Which complex is likely to show optical activity :

Options

A. `trans-[Co(NH_(3))_(4)Cl_(2)]^(-)`
B. `[Cr(H_(2)O)_(6)]^(3+)`
C. `cis-[Co(NH_(3))_(2)(en)_(2)]^(3+)`
D. `trans-[Co(NH_(3))_(2)(en)_(2)]^(3+)`

Answer

C

Explanation

(1) `trans-[Co(H_(2)O)_(6)]^(3+)` has plane of symmetry as well as centre of symmetry. Hence it does not show optical isomerism.
(2) `[Cr(H_(2)O)_(6)]^(3+)` has plane of symmetry as well as centre of symmetry. Hence it does not show optical isomerism.
(3) `cis-[Co(NH_(3))_(2)(en)_(2)]^(3+)` lackls one of the symmetry elements.

(4) `trans-[co(NH_(3))_(2)(en)_(2)]^(3+)` has plane of symmetry as well as centre of symmetry. Hence it does not show optical isomerism.