Molecular orbital studies of aminoanthraquinones

Abstract

Both the Hückel and CNDO/2 methods have been used to calculate the charge densities and localisation energies of 1- and 2-aminoanthraquinones. It is found that a reasonably good correlation exists between the calculated and experimentally determined positions of ring substitution as assessed by the halogenation, nitration, and sulphonation of these systems. The experimentally determined substitution patterns obtained for 1- and 2-methyl-aminoanthraquinone show considerable differences from their amino-analogues suggesting that the methyl group is exerting a considerable steric effect in these reactions.