Nitrogen-15 tracer evidence discounting the occurrence of a cyclic azide intermediate in the reaction between nitrous acid and hydrazine

Abstract

Analysis by ¹⁵N NMR spectroscopy of a sample of hydrazoic acid isolated from a reaction mixture of labelled hydrazine and nitrous acid has shown that there is no rearrangement of tracer, and that the earlier suggestion of a cyclic azide intermediate must be discarded. Mass-spectrometric analyses of the evolved dinitrogen and dinitrogen monoxide showed that there are probably three distinct pathways by which reaction proceeds, one via the formation of hydrazoic acid, one via the dinitrosated species ONNHNHNO and a third route which leads to an excess of doubly labelled N₂ which may involve HNN–N(NO)OH.