AM1 STUDY OF SINGLE-ATOM PERI-BRIDGED NAPHTHALENES

peri-Bridged naphthalenes in which the C-1 and C-8 atoms of the naphth alene ring are bonded to a single atom in a bridging group Z (Z=CH2, C HBr, C=O, NH, O, S, S=O and SO2) sere studied by the AM1 semi-empirica l SCF MO method. Although in peri-naphthalenes bridged by carbon or su lfur the naphthalene structure is planar, the corresponding nitrogen- or oxygen-bridged molecules are distorted about 15 and 23 degrees, res pectively. There are significant variations (from 92 to 106 degrees) o f the C-1-C-9-C-8 angle that is calculated in the cycle formed by the bridge, The calculated strain-energy barrier for pyramidal atom invers ion in amine 4 and sulfoxide 7 are 32.5 and 174 kJ mol(-1), respective ly.