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 AND THE EXOCYCLIC BOND-LENGTH VARIATION( )

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 str uctural consequences in naphthalene moiety. It results that rotation a round and elongation of this bond lead to the fluctuation of the elect ronic charge at atoms and variation of CC bond length in the whole moi ety. The latter changes allow to evaluate variation in aromatic charac ter of both rings in the system leading to the conclusion that rotatio n is a more substantial factor causing decrease of aromaticity than th e mere elongation. Changes in the aromatic character are greater in th e case of 2-substituted species than those observed in position 1. (C) 1998 Elsevier Science Ltd. All rights reserved.