How many of the following compounds have non zero dipole moments is.

Question

How many of the following compounds have non zero dipole moments is. (A)  (B)  (C)  (D)

Tardigrade Admin · Accepted Answer

(a), (b), (d) and (e) are benzene and fused benzene ring complexes. As benzene is symmetrical and have zero dipole moment, the fused ring molecules will also have zero dipole moments.
(c) is an azulene which is an aromatic compound and a structural isomer of naphthalene. The polarity can be explained by regarding azulene as the fusion of

a 6 π

- electron cyclopentadienyl anion and a

6 π

-electron tropylium cation.
One electron from a

7

-membered ring is transferred to the

5

-membered ring to give each ring aromatic stability.

This gives it a dipole moment of

1.08 D

.
(f) will have a considerable dipole moment due to non-linear dipole moment generated by

2 - O H

groups.

Q. How many of the following compounds have non zero dipole moments is_____.