Aromaticity of bent benzene rings: A VBSCF study

The effect of ring deformation on aromaticity has been studied for bent ben zene molecules in which two carbon atoms have been bent out of plane, resul ting in a boat conformation. Valence-bond self-consistent field (VBSCF) cal culations have been performed on these molecules to obtain insight into the aromaticity of bent benzenes. Results for total energy, structure energies , weights, and orbital overlaps show that the molecule keeps its aromatic n ature up to 55 degrees. After 55 degrees a transition to Dewar benzene occu rs. The valence-bond model, by showing the weights of both Dewar and Kekule structures, is an excellent tool to study deformed benzene. (C) 1999 John Wiley & Sons, Inc.