Name the type of isomerism exibited by the following isomers :
(1) `[Cr(NH_(3))_(6)][Cr(CN)_(6)] and [Cr(NH_(3))_(4)(CN)_(2)][Cr(NH_(3))_(2)(CN)_(4)]`
(2) `[Co(py)_(2)(H_(2)O)_(2)Cl_(2)]Cl and [Co(py)_(2)(H_(2)O)Cl_(3)]H_(2)O`
(3) `[Pt(NH_(3))_(4)Br_(2)]Cl_(2) and [Pt(NH_(3))_(4)Cl_(2)]Br_(2)`
(4) `[Co(NH_(3))_(5)NO_(2)]Cl_(2) and [Co(NH_(3))_(5)ONO]Cl_(2)`

Options

A. `(i)` only
B. `(i)` and `(ii)` only
C. `(ii)` and `(iii)` only
D. `(iii)` and `(iv)` only.

Answer

1

Explanation

`(i)` Coordination compounds made up of cationic and anionic coordination entities show coordination isomerism due to the interchange of ligands between the cation and anion entities.
`(ii)` Hydrate isomers differ by whether or not a water molecule is directly bonded to the metal ion or merely present as free water molecules in the crystal lattice.
`(iii)` Ionisation isomerism occurs when the counter ion in a coordination compounds is itself a potential ligand and can displace a ligand which can then become the counter ion.
`(iv)` `[NiCl_92)9PPh_(3))_(2)]` has tetrahedral geometry on account of the bulkier nature of triphenyl phosphine. In tetrahedral geometry all position are adjacent to each other and therefore , does not show geometrical isomerism.