Question

Which of the following will show optical isomerism ?

• A. $\left[Cu\right(N{H}_3{)}_4{]}^{2+}$
• B. $[ZnC{l}_4{]}^{2-}$
• C. $\left[Cr\right(C_2{O}_4{)}_3{]}^{3-}$
• D. $\left[Co\right(CN{)}_6{]}^{3-}$

Answer 1

The correct option is C $\left[Cr\right(C_2{O}_4{)}_3{]}^{3-}$

Optical isomers rarely occur in square planar complexes on account of the presence of the axis of symmetry. Optical isomerism is very common in octahedral complexes.

Optical isomerism is very common in octahedral complexes having general formula $[M{A}_2{B}_2{C}_2{]}^{n-}$, $\left[M\right(AA{)}_3{]}^{n-},$ $M(AA{)}_2{B}_2{]}^{n-},[M(AA{)}_{2}AB{]}^{n-}$, and $\left[M\right(AB{)}_3{]}^{n-}$ where $AA$ is symmetrical bidentate ligand such as

$\stackrel{CO{O}^{-}}{\stackrel{|}{C}}O{O}^{-}$ and $AB$ is an unsymmetrical bidentate ligand.

Hence, option C is correct.