Which of the folloiwng complexes in not expected to exhibit optical isomerism? .

Options

A. (a) `[Co(en)_3Cl_2]^(+)`
B. (b) `[Co(en)_2Cl_2]^(+)`
C. (c) `[Co(NH_3)_3Cl_3]`
D. (d) `[Co(en)(NH_3)Cl_2]^(+)`

Answer

C

Explanation

Optical isomerism is exhibited by only those complexes which lack elements of symmetry.
`[Co(NH_3)_3Cl_3]` shows facial as well as meridional isomerism. But both the forms contain plane of symmetry. Thus, this complex does not exhibit optical isomerism.