Hazardous N-containing system: Thermochemical and computational evaluation of the intrinsic molecular reactivity of some aryl azides and diazides

The exothermic decompositions of the tosyl azide 1, five substituted aryl monoazides 2-6 and two diazides: 1-azido-4-(4-azidophenoxy)benzene 7 and 1-azido-4-[(4-azidophenyl)sulfanyl]benzene 8 were studied experimentally using DSC, weight loss TGA-FTIR and C80-FTIR techniques, and theoretically using the CHETAH software. Numerical modelling and electron impact mass spectrometry (EI-MS) were also performed to investigate the nature of the intrinsic molecular reactivity of azides 1-8, and the possible early stage rate-controlling of an oxidative self-heating process. Significant data were obtained in the instances of 4-methylbenzenesulfonyl azide 1, 4-azido-1,1′-biphenyl-2,2-azido-1, 1′-biphenyl 3 and 1-azido-2-(trifluoromethyl)benzene 6. The most likely decomposition pathways of the azides are proposed to explain the observed thermal behavior. © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.