What Is A Coordination Compound?

A coordination complex is the product of a Lewis acid-base reaction in which neutral molecules or anions (called ligands) bond to a central metal atom (or ion) by coordinate covalent bonds.

Coordination compounds and complexes are distinct chemical species - their properties and behavior are different from the metal atom/ion and ligands from which they are composed.

The coordination sphere of a coordination compound or complex consists of the central metal atom/ion plus its attached ligands. The coordination sphere is usually enclosed in brackets when written in a formula.

The coordination number is the number of donor atoms bonded to the central metal atom/ion.

Some Coordination Complexes
example	molecular formula	Lewis base/ligand	Lewis acid	donor atom	coordination number
Jmol._Canvas2D (JSmol) "jmolApplet0"[x] call loadScript core\corescript.z.js starting QueueThread0_2 script 1 started call loadScript core\corestate.z.js FileManager.getAtomSetCollectionFromFile(lin2.xyz) //XYZ::lin2.xyz starting HoverWatcher_3 FileManager opening https://www.chem.purdue.edu/jmol/cchem/lin2.xyz The Resolver assumes Xyz Time for openFile(XYZ::lin2.xyz): 111 ms reading 9 atoms ModelSet: haveSymmetry:false haveUnitcells:false haveFractionalCoord:false 1 model in this collection. Use getProperty "modelInfo" or getProperty "auxiliaryInfo" to inspect them. Default Van der Waals type for model set to Babel 9 atoms created ModelSet: autobonding; use autobond=false to not generate bonds automatically Jmol JavaScript applet jmolApplet1_object__250604178493052__ initializing getValue debug = null getValue logLevel = null AppletRegistry.checkIn(jmolApplet1_object__250604178493052__) viewerOptions: { "name":"jmolApplet1_object","applet":true,"documentBase":"https://www.chem.purdue.edu/jmol/cchem/whatis.html","platform":"J.awtjs2d.Platform","fullName":"jmolApplet1_object__250604178493052__","display":"jmolApplet1_canvas2d","signedApplet":"true","appletReadyCallback":"Jmol._readyCallback","statusListener":"[J.appletjs.Jmol.MyStatusListener object]","codeBase":"https://www.chem.purdue.edu/jmol/cchem/j2s/","syncId":"250604178493052","bgcolor":"white" } (C) 2012 Jmol Development Jmol Version: 13.1.14_dev $Date: 2013-02-27 13:04:34 -0600 (Wed, 27 Feb 2013) $ java.vendor: j2s java.version: 0.0 os.name: j2s Access: ALL memory: 0.0/0.0 processors available: 1 useCommandThread: false appletId:jmolApplet1_object (signed) starting HoverWatcher_5 getValue emulate = null defaults = "Jmol" getValue boxbgcolor = null getValue bgcolor = white backgroundColor = "white" getValue ANIMFRAMECallback = null getValue APPLETREADYCallback = Jmol._readyCallback APPLETREADYCallback = "Jmol._readyCallback" getValue ATOMMOVEDCallback = null getValue CLICKCallback = null getValue ECHOCallback = null getValue ERRORCallback = null getValue EVALCallback = null getValue HOVERCallback = null getValue LOADSTRUCTCallback = null getValue MEASURECallback = null getValue MESSAGECallback = null getValue MINIMIZATIONCallback = null getValue PICKCallback = null getValue RESIZECallback = null getValue SCRIPTCallback = null getValue SYNCCallback = null language=en_US getValue script = null Jmol applet jmolApplet1_object__250604178493052__ ready	[Ag(NH₃)₂]⁺	NH₃	Ag⁺	N	2
Jmol._Canvas2D (JSmol) "jmolApplet1"[x] starting QueueThread0_6 script 1 started FileManager.getAtomSetCollectionFromFile(zncn4.pdb) //PDB::zncn4.pdb starting HoverWatcher_7 FileManager opening https://www.chem.purdue.edu/jmol/cchem/zncn4.pdb The Resolver assumes Pdb call loadScript core\corebio.z.js Time for openFile(PDB::zncn4.pdb): 168 ms reading 9 atoms ModelSet: haveSymmetry:false haveUnitcells:false haveFractionalCoord:false 1 model in this collection. Use getProperty "modelInfo" or getProperty "auxiliaryInfo" to inspect them. Default Van der Waals type for model set to Jmol 9 atoms created ModelSet: not autobonding; use forceAutobond=true to force automatic bond creation spinY = 180 specularExponent = -6 specularPercent = 50 specularPower = 70 Script completed Jmol script terminated	[Zn(CN)₄]^2-	CN^-	Zn²⁺	C	4
Jmol._Canvas2D (JSmol) "jmolApplet2"[x]	[Ni(CN)₄]^2-	CN^-	Ni²⁺	C	4
Jmol._Canvas2D (JSmol) "jmolApplet3"[x]	[PtCl₆]^2-	Cl^-	Pt⁴⁺	Cl	6
Jmol._Canvas2D (JSmol) "jmolApplet4"[x] call loadScript core\package.js call loadScript core\core.z.js -- required by ClazzNode Jmol JavaScript applet jmolApplet0_object__125449835227935__ initializing getValue debug = null getValue logLevel = null AppletRegistry.checkIn(jmolApplet0_object__125449835227935__) viewerOptions: { "name":"jmolApplet0_object","applet":true,"documentBase":"https://www.chem.purdue.edu/jmol/cchem/whatis.html","platform":"J.awtjs2d.Platform","fullName":"jmolApplet0_object__125449835227935__","display":"jmolApplet0_canvas2d","signedApplet":"true","appletReadyCallback":"Jmol._readyCallback","statusListener":"[J.appletjs.Jmol.MyStatusListener object]","codeBase":"https://www.chem.purdue.edu/jmol/cchem/j2s/","syncId":"125449835227935","bgcolor":"white" } (C) 2012 Jmol Development Jmol Version: 13.1.14_dev $Date: 2013-02-27 13:04:34 -0600 (Wed, 27 Feb 2013) $ java.vendor: j2s java.version: 0.0 os.name: j2s Access: ALL memory: 0.0/0.0 processors available: 1 useCommandThread: false appletId:jmolApplet0_object (signed) starting HoverWatcher_1 getValue emulate = null defaults = "Jmol" getValue boxbgcolor = null getValue bgcolor = white backgroundColor = "white" getValue ANIMFRAMECallback = null getValue APPLETREADYCallback = Jmol._readyCallback APPLETREADYCallback = "Jmol._readyCallback" getValue ATOMMOVEDCallback = null getValue CLICKCallback = null getValue ECHOCallback = null getValue ERRORCallback = null getValue EVALCallback = null getValue HOVERCallback = null getValue LOADSTRUCTCallback = null getValue MEASURECallback = null getValue MESSAGECallback = null getValue MINIMIZATIONCallback = null getValue PICKCallback = null getValue RESIZECallback = null getValue SCRIPTCallback = null getValue SYNCCallback = null language=en_US getValue script = null Jmol applet jmolApplet0_object__125449835227935__ ready	[Ni(NH₃)₆]²⁺	NH₃	Ni²⁺	N	6