Photochemistry of aryl azides: detection and characterization of a dehydroazepine by time-resolved infrared spectroscopy and flash photolysis at room temperature

The authors report herein investigation of the photochemistry of 4-(dimethylamido)phenyl azide at room temperature in fluid solution by transient absorption techniques with detection by infrared and ultraviolet spectroscopy. These experiments establish with certainty the intermediacy of 5-(dimethylamido)-1,2-dehydroazepine, identify it as the species trapped by nucleophiles, permit the estimation of its lifetime, and allow measurement of the rate of its reaction with diethylamine.