Which of the following complex species is not expected to exhibit optical isomerism ?

Options

A. `[Co(en)(NH_(3))_(2)Cl_(2)]^(+)`
B. `[Co(en)_(3)]^(3+)`
C. `[Co(en)_(2)Cl_(2)]^(+)`
D. `[Co(NH_(3))_(3)Cl_(3)]`

Answer

D

Explanation

`[Co(NH_(3))_(3)Cl_(3)]` shows cis or facial (fac) as well as trans or meridional (mer) isomers. But both these isomers contain plane of symmetry. So they do not exhibit optical isomerism.