Crystal structure of hydrobromides of pyridines and quinolines N-oxides

Abstract

Structures of hydrobromides of quinoline, 4-methylquinoline, pyridine, and 4-methylpyridine N-oxides have been elucidated by means of X-ray diffraction analysis. In contrast to other salts, quinoline N-oxide hydrobromide crystallizes in the form of dimer with two water molecules. The oxygen atom of the organic molecule is coordinated with water protons, and its state is close to sp²-hybridization. In the cases of other hydrobromides, the oxygen atom is strongly bound to the proton of НBr and exhibits sp³-hybridization.