Question

Which of the following is optically inactive?

• A.
• B.
• C.
• D.

Answer 1

The correct option is A

Biphenyl Systems show optical activity when the following conditions are satisfied:

• Each ring should have 2 different ortho substituting groups.

In a each ring have 2 different ortho substituting groups $(-COOH$ and $N{O}_2.$ thus it is optically active.

In even cumulenes, having different terminal atoms/groups, two mutually perpendicular π bonds are formed. Hence, the terminal atoms/groups attached to the terminal $s{p}^2$ carbons are in different planes. So, elements of symmetry (POS, COS) are absent. Hence, even-cumulenes are optically active. so b and d are optically inactive.


c is not chiral carbon because 4 different group is not present on central carbon hence it is optically inactive.