Change in the hybridization of the N→O group oxygen atom upon complex formation of pyridine and quinoline N-oxides with v-acceptors

Abstract

It was shown on the basis of X-ray structural and NMR data that the (sp 2→sp 3) rehybridization of the oxygen atom of the N→O group can take place in reactions of heteroaromatic N-oxides with Lewis and Bronsted-Lowry acids. The hybridization type depends on the ligand and acceptor natures, composition of a complex, and spatial stresses arising during the complex formation.