Which of the following does not show optical isomerism ?

Options

A. `[Co(en)_(2)Cl_(2)]^(+)`
B. `[Co(NH_(3))_(3)Cl_(3)]^(0)`
C. `[Co(en)Cl_(2)(NH_(3))_(2)]^(+)`
D. `[Co(en)_(3)]^(3+)`

Answer

B

Explanation

Optical isomerism is exhibited only by those complexes in which plane of symmetry are absent Octahedral complexes of the types`[M(aa)_(3)], [M(aa)_(x_(2)),y_(2)]" and "[M(aa)_(2)X_(2)]` have absence of plane of symmetry, thus exhibit. optical isomerism Here, aa represents bidentate ligand, x or y represents monodentate ligand and M represents central metal ion.
Hence, `[Co(NH_(3))_(3)Cl_(3)]^(0)` due to presence of symmetry elements does not exhibit optical isomerism.
Or
Octahedral complexes of `[M("AA")_(2)B_(2)]" type , e.g. "[Co(en)_(2)Cl_(2)]^(+),[M("AA")B_(2)C_(2)]" type, e.g. "[Co(en)_(3)]^(3+)` show optical isomensim, whereas complexes of `[MA_(3)B_(3)]" type, e.g. "[Co(NH_(3))Cl_(2)]^(0)` do not show optical isomerism.