Question

Where among the following metal complexes the one which exhibits optical activity is: ($AA=$ bidentate ligand; $X=$ monodentate ligand)

• A. $cis-\left[M{A}_4{X}_2\right]$
• B. $trans-\left[M{A}_4{X}_2\right]$
• C. $cis-\left[M\right(AA{)}_2{X}_2]$
• D. $trans-\left[M\right(AA{)}_2{X}_2]$

Answer 1

The correct option is C $cis-\left[M\right(AA{)}_2{X}_2]$

In the octahedral complexes of the type $M(AA{)}_2{X}_2$ like $\left[Co\right(en{)}_{2}C{l}_2{]}^{+}$ :

The cis isomer exist in two optical isomers. In the case of trans isomer optical isomerism not possible.

In octahedral complexes of the type $M(A{)}_4{X}_2$ like $\left[Co\right(N{H}_3{)}_{4}C{l}_2{]}^{+}$ the optical isomerism is not possible.