Didehydroazepines from the photolysis of phenyl azide and 3- and 4-substituted phenyl azides isolated in low-temperature matrices

Abstract

Phenyl azide, its ¹⁵N-labelled derivative (Ph¹⁵NNN), and a series of 3- and 4-substituted phenyl aiides have been photolysed in N₂ and Ar matrices at 12 K. In all cases, the major decomposition pathways yield didehydroazepines with characteristic i.r. absorptions at ca. 1 890 cm^–1. Neither the reaction pathway nor the characteristic group frequency of the didehydroazepines seem much affected by variation of the substituents.