Chapter 18, Problem 54IP

Interpretation Introduction

Interpretation: By analyzing the resonance structures, the dipole moment of azulene should be explained and for the given compounds, larger dipole moment exhibiting compound should be determined.

Concept introduction:

• A five membered ring will be aromatic if it contains six $\text{π}$ electrons. In order to have six $\text{π}$ electrons, one of the carbon atoms must possess two electrons. It should be a carbanion.
• A seven membered ring will be aromatic if it contains six $\text{π}$ electrons. In order to have six $\text{π}$ electrons in a seven membered ring one of the carbon atom must possess an empty p orbital. This carbocation exhibits a continuous system of overlapping and p orbitals and has six $\text{π}$ electrons.
• Aromatic compounds are more stable than non-aromatic compound
• If the resonance structures of the compound are aromatic and these resonance structures contribute significant character to the overall resonance hybrid, then the compound will have significant dipole moment