Chapter 15, Problem 58P

Interpretation Introduction

Interpretation:

The difference in behavior in halogen substituted azulenes, a halogen atom on carbon 6 atom is displaced by nucleophiles, while on carbon 1 atom, it is unreactive; is to be explained.

Concept introduction:

Resonance is an idea to explain the bonding in a molecule having delocalized electrons, that results in the formation of many resonance structures that collectively constitute a resonance hybrid.

In order to be aromatic, a molecule should be cyclic, planar, and uninterrupted $\pi$ electrons.