Chapter 17, Problem 17.33P

Interpretation Introduction

Interpretation: Among the given heterocycles, the aromatic compounds are to be determined.

Concept introduction: A molecule must be cyclic, planar, completely conjugated and should follow Huckel’s rule to be classified as aromatic. For an antiaromatic molecule, the molecule must be cyclic, planar, completely conjugated and have $4n\pi$ electrons. For a non-aromatic molecule, the molecule lacks the one of the requirements to be aromatic or anti aromatic molecule.

According to the Huckel’s rule, the aromatic compound must contain $\left(4n+2\right)\pi$ electrons.