Electronic Structure and Spectra of Biphenyl and Its Related Compound

Abstract

The Pariser—Parr method has been used to elucidate the electronic structure and the spectrum of biphenyl. The absorptions at 300, 250, 200, and 170 mμ seem to be explained reasonably. Simple forms of linear combinations of the symmetry orbitals constructed from 2pπAO's were used as molecular orbitals. Calculations were made for three conformations, the angle between the planes of two benzene rings being 0°, 45°, or 90°. In each of the conformations 16 singlet and 16 triplet excited configurations were taken into account. An application has been made to 2,2′‐bipyridyl, and its absorption spectrum has been explained.