The theoretical conformational analysis of some bridged aromatic compounds: diphenyl ether, diphenylmethane, benzophenone and diphenyl sulphide

Abstract

A conformational analysis of the bridged aromatic compounds PhXPh with X = O, CH2, CO, and S has been carried out. The conformational energy maps for PhOPh calculated by different quantum chemical methods (EHT, CNDO/2, MINDO/2, PCILO) are substantially different. Comparison of the quantum chemical results for PhOPh with the results of classical conformational calculations, and with experimental data, show that the EHT and CNDO/2 methods give satisfactory results, in contrast to the MINDO/2 and PCILO methods. The EHT method is then applied to all the studied molecules. The dependence of the dielectric relaxation times of these compounds on the main features of internal rotation and the flexibility of macromolecules with skeletal PhXPh groups are discussed. © 1975.