Question

Which of the following compounds shows optical isomerism?

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

Answer 1

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

Optical isomerism is very common with octahedral complexes of the type $M(AA{)}_3,M(AA{)}_{2}AB,M\left(AA\right)A_2{B}_2,M\left(AA\right)\left(BB\right)A_2$ etc. A few typical examples are shown in the figure.

In $\left[Cr\right(C_2{O}_4{)}_3{]}^{3-}$, all the 3 same bidentate ligands exist in different planes and no plane of symmetry so it will show optical isomerism.

Option A is correct.