A Molecular Orbital Description of Aromaticity and Antiaromaticity

Why are compounds with tt clouds highly stable (aromatic) if the tt cloud contains an odd number of pairs of tt electrons but highly unstable (antiaromatic) if the tt cloud contains an even number of pairs of tt electrons To answer this question, we must turn to molecular orbital theory. [Pg.350]

Aromatic compounds are stable because they have filled bonding tt molecular orbitals. [Pg.350]

The distribution of electrons in the rr molecular orbitals of (a) benzene, (b) the cyclopentadienyl anion, (c) the cyclopentadienyl cation, and (d) cyclobutadiene. [Pg.350]

Big Chemical Encyclopedia