In one example the choloride is bound to the cobalt and bromide is the counter ion. In the other coordination isomer the bromide is coordinated to the cobalt and chloride is the counter ion

Linkage isomers contain the same ligands but one or more of the ligands are coordinated to the metal through a different atoms. These ligands are said to be ambidentate. A ligand that has lone pairs on two different atoms can potentially be ambidentate

In this example, nitrite ion NO2- is ambidentate and may be bound through either the lone pair on the central nitrogen atom or the lone pare on the oxygen. This gives rise to two linkage isomers.

In this case, the spatial orientation of ligands is such that the two isomers are non-super imposable mirror images of one another. There are two common occurences of this type of isomerism

(i) cis-isomers of octahedral complexes with 2 bidentate ligands and 2 monodentate ligands (cis-bis chelates)

(ii) octahedral complexes with 3 bidentate ligands (tris chelates)

Note that trans isomers cannot be optical isomers