Question

Which of the following complex show optical isomerism?
$(i) \text{cis} - [\text{COCl}(\text{en})_2 (\text{NH}_3)]^{2+} $ 
$(ii) \text{cis} - [\text{CrCl}_2(\text{ox})_2]^{3-}$ 
$(iii) \text{cis} - [\text{CO}(\text{en})_2\text{Cl}_2]\text{Cl}$ 
$(iv) \text{cis} - [\text{CO}(\text{NH}_3)_4 \text{Cl}_2]^+$

• A. (i), (ii), (iii)
• B. (i), (ii)
• C. (i), (iv)
• D. (i), (ii), (iv)

Hint:

For a complex to show optical isomerism, it must lack any symmetry and must have a non-superimposable mirror image, typically arising from a cis configuration.

Answer 1

The Correct Option is A

Optical isomerism occurs when a molecule cannot be superimposed on its mirror image, i.e., it has chirality. 
The complexes (i), (ii), and (iii) exhibit optical isomerism because they have cis configurations and involve non-superimposable mirror images due to the arrangement of ligands around the central metal ion. 
However, the complex (iv) does not exhibit optical isomerism as it is a symmetric structure.