Question

Which of the following compounds has the greater dipole moment ?

• A. left compound
• B. right compound
• C. both have same
• D. none of these

Answer 1

The correct option is A left compound

The left compound has the greater dipole moment.

In the case of the compound on the left, the three-member ring becomes aromatic when the charges are separated.

In the case of the compound on the right, the resonance contributor with separated charges does not have any additional aromaticity. Thus, the resonance contributor with separated charges is more stable and, therefore, makes a greater contribution to the hybrid for the compound on the left than for the compound on the right.

The compound on the left, therefore, has the greater dipole moment.