question_answer

In which of the following pairs both the complexes show optical isomerism?

A) \[cis-{{[Cr{{({{C}_{2}}{{O}_{4}})}_{2}}C{{l}_{2}}]}^{3-}}\,cis-[Co{{(N{{H}_{3}})}_{4}}C{{l}_{2}}]\]

B) \[[Co{{(en)}_{3}}]C{{l}_{3}},cis-[Co{{(en)}_{2}}C{{l}_{2}}]Cl\]

C) \[[PtCl(diem)]Cl,\,{{[NiC{{l}_{2}}B{{r}_{2}}]}^{2-}}\]

D) \[[Co{{(N{{O}_{3}})}_{3}}{{(N{{H}_{3}})}_{3}}],cis-Pt{{(en)}_{2}}C{{l}_{2}}]\]

Correct Answer: B

Solution :

Both \[cis-[Co{{(en)}_{3}}]C{{l}_{3}}\] and \[cis-[Co{{(en)}_{2}}]Cl\] show optical isomerism. Optical isomers are non-super imposable mirror images of each other. Compounds with co-ordination number 4 and 6 show optical isomerism.

Co-ordination no.	Type
4	\[M{{(AB)}_{2}}\]
6	\[[M(AA){{X}_{2}}{{Y}_{2}}],\] \[[M{{(AA)}_{2}}{{X}_{2}})\] or \[[M{{(AA)}_{2}}XY)\] \[[M{{(AA)}_{3}})]\]