Chapter 15, Problem 49P

Interpretation Introduction

Interpretation: The pattern of molecular orbitals in cyclonona-$1,3,5,7$-tetraene, using the inscribed polygon method is to be shown and its cation, radical, and anion are to be labeled as aromatic, antiaromatic, or not aromatic.

Concept introduction: The inscribed polygon method is helpful to predict whether a compound involves completely filled bonding $\text{MOs}$ or not. The all bonding $\text{MOs}$, and the $\text{HOMOs}$ of an aromatic compound are completely filled. However, the antibonding $\text{MOs}$ are completely vacant.