Chapter 15.6, Problem 11P

Interpretation Introduction

Interpretation:

Whether azulene, an isomer of naphthalene, is aromatic or not is to be stated. Another resonance form of azulene in addition to that shown is to be drawn.

Concept introduction:

According to Huckel’s rule a planar, cyclic conjugated system will be aromatic if it contains (4n+2)Ï€ electrons. Systems with 4nÏ€ electrons will be antiaromatic.

Resonance structures differ only in the position of lone pair or its π electrons. The position of atoms in different resonance forms do not differ. They do not represent the actual structure of the molecule. The actual structure is a hybrid of all the resonance forms possible.

To state:

Whether azulene, an isomer of naphthalene, is aromatic.

To draw:

Another resonance form of azulene in addition to that shown.