Question

Which of the following cannot show geometrical isomerism?

• A. $PhNH.N{H}_2$
• B. $H-N=N-C{H}_3$
• C.
• D. None of the above

Answer 1

The correct option is A $PhNH.N{H}_2$

Geometrical Isomerism arises due to different arrangement of atoms/groups around a system where free rotation of bonds is restricted.

Conditions for Geometrical Isomerism:
1. Free rotation must be restricted
2. Both the terminals of the system must be attached with different atoms/groups.

In compound (a), free rotation is not restricted. Hence, it does not show geometrical isomerism.


Compound (b) and (c) have different groups attached to the terminals of the system and their free rotation is restricted.