Unique zwitterionic explosophore azasydnonimine: thermal stability, decomposition and combustion mechanism of aromatic derivatives

A study of the thermal stability of derivatives of one of the most energetic heterocycle, azasydnonimine, was carried out. It has been shown that the azasydnonimine cycle has satisfactory stability which grows with an increase in the electronegativity of the substituent at the imine group. The combustion behaviors of azasydnonimine derivatives have been investigated, and the temperature distribution in their combustion waves has been measured using thin thermocouples. Based on the obtained dependences of the surface temperature and burning rate on pressure, it was found that the burning rate of 3-phenyl-1,2,3,4-oxatriazolium-5-phenylamide (ASI-1) is determined by the fast kinetics of autocatalysis of decomposition in the melt at the temperature of burning surface. In the case of 3-(3-nitrophenyl-1,2,3,4-oxatriazolium-5-(2,4,6-trinitrophenyl)aminid (ASI-2), a peculiar Merzhanov-Dubovitsky combustion mechanism is realized, according to which a part of the heat is released in the aerosol droplets, and the rest of the heat required for the propagation of combustion comes from the gas phase.