Question

Which of the following can show coordination isomerism? (1) $[Cu{(N{H}_3)}_4][PtC{l}_4]$ (2) ${[Fe{(N{H}_3)}_6]}_2{[Pt{(CN)}_6]}_3$ (3) $[Co{(N{H}_3)}_6][Cr{(C_2{O}_4)}_3]$ (4) $[Pt{(en)}_3]{(S{O}_4)}_2$

• A. 1, 2 and 3 are correct.
• B. 1 and 2 are correct.
• C. 2 and 4 are correct.
• D. 1 and 3 are correct.

Answer 1

Answer: (D)

The compounds in which cation and anion both are complex and metals have same coordination number, exhibit coordination isomerism. It involves the exchange of ligands between cation and anion. (i) $\begin{array}{rl}& [Cu{(N{H}_3)}_4][PtC{l}_4,]\\ & [CuC{l}_4][Pt{(N{h}_3)}_4]\end{array}\}(coordinationisomers)$ $C.N.=4$ (ii) $\begin{array}{rl}& [Co{(N{H}_3)}_6][Cr{(C_2{O}_4)}_3],\\ & [Co{(C_2{O}_4)}_3][Cr{(N{H}_3)}_6]\end{array}\}(coordinationisomers)$ $C.N=6[\because C_2{O}_{4}isbidentateligand]$