Which of the following complexes can exists as diastereoisomer ?

Options

A. `[Cr(NH_(3))_(2)Cl_(4)]^(-)`
B. `[Co(NH_(3))_(5)Br]^(2+)`
C. `[FeCl_(2)(NCS)_(2)]^(2-)`
D. `[PtCl_(2)Br_(2)]^(2-)`

Answer

A, D

Explanation

(A) Exists as cis and trans form but neither of the forms can have enetiomeric forms on account of presence of the plane of symmetry as well as centre of symmetry.
(B) Only one form possible .
( C) Tetrahedral in which all positions are adjacent to each other.
(D) Exists as cis and trans form but neither of the forms can have enantiomeric form on account of presence of the plane of symmetry.