List various types of isomerism possible for coordination compounds, giving an example of each.

(a) Geometric isomerism: This type of isomerism is common in heteroleptic complexes. It arises due to the different possible geometric arrangements of the ligands. For example: (b) Optical isomerism: This type of isomerism arises in chiral molecules. Isomers are mirror images of each other and are non-superimposable. (c) Linkage isomerism: This type of isomerism is found in complexes that contain ambidentate ligands. For example: [Co(NH3)5 (NO2)]Cl2 and [Co(NH3)5 (ONO)Cl2 Yellow form Red form (d) Coordination isomerism: This type of isomerism arises when the ligands are interchanged between cationic and anionic entities of differnet metal ions present in the complex. [Co(NH3)6] [Cr(CN)6] and [Cr(NH3)6] [Co(CN)6] (e) Ionization isomerism: This type of isomerism arises when a counter ion replaces a ligand within the coordination sphere. Thus, complexes that have the same composition, but furnish different ions when dissolved in water are called ionization isomers. For e.g., Co(NH3)5SO4)Br and Co(NH3)5Br]SO4. (f) Solvate isomerism: Solvate isomers differ by whether or not the solvent molecule is directly bonded to the metal ion or merely present as a free solvent molecule in the crystal lattice. [Cr[H2O)6]Cl3 [Cr(H2O)5Cl]Cl2⋅H2O [Cr(H2O)5Cl2]Cl⋅2H2O Violet Blue-green Dark green read less