Separation of the energetic and geometric contributions to aromaticity. Part VII. Changes of the aromatic character of the rings in naphthalene induced by the charged substituent CH2+. The dependence on the position of the substitution, torsion angle

摘要

The 1- and 2-CH2+ derivatives are studied in terms of variation of the C-C exocyclic bond and the torsion around it in order to show the structural consequences in naphthalene moiety. It results that rotation around and elongation of this bond lead to the fluctuation of the electronic charge at atoms and variation of CC bond length in the whole moiety. The latter changes allow to evaluate variation in aromatic character of both rings in the system leading to the conclusion that rotation is a more substantial factor causing decrease of aromaticity than the mere elongation. Changes in the aromatic character are greater in the case of 2-substituted species than those observed in position 1. (C) 1998 Elsevier Science Ltd. All rights reserved. [References: 12]