Lone pairs and molecular structure: The Conformation of the o,o′‐Azabiphenyls

Abstract The conformational structure of the o,o′‐azabiphenyls was examined using the NDDO method. The planarity or nonplanarity of the various compounds is the result of a compromise between the stabilizing conjugation effect and the destabilizing interactions of the nitrogen lone pairs and the steric hindrance of the ortho hydrogen atoms, respectively. There are no destabilizing interactions between the ortho hydrogens and nitrogen lone pairs. A detailed analysis of the results provides more insight into the problems of the treatment of lone pairs within NDO methods.