: Compounds (I) and (II) both contain complex cation and anion, so they show coordination isomerism. Compounds (III) and (IV) are obtained by the interchange of groups outside the coordination sphere and the ligands within the coordination sphere. Therefore, they give different ions in the solution. Hence, they show ionisation isomerism. Compounds (V) and (VI) are linkage isomers, because the ambidentate ligand, has two donor atoms, i.e., it has two possibilities of attachment (-SCN and - NCS) with the central metal. Hence, they show linkage isomerism.
Compounds (VII) and (VIII) are obtained by the replacement of a coordinated group such as by water of hydration. Hence, they show hydrate isomerism.