Kinetics of the Decomposition of 1,1-Diamino-2,2-Dinitroethylene (FOX-7). Part 4: Comparison of the Decomposition Reactions of FOX-7 and Its Diazacyclic Derivatives

The kinetics of the thermal decomposition of diazacyclic derivatives of 1,1-diamino-2,2-dinitroethylene (FOX-7) in a dilute solution of nitrobenzene and in the solid phase are studied by manometric and calorimetric methods. The activation energy data obtained for the solution are used for comparison with quantum chemical calculations and for establishing the relationship between the stability of compounds and the structure of the molecules. The decomposition of these derivatives in solution proceeds according to the same mechanism as the decomposition of FOX-7. Their activation energies decrease with the increasing C=C bond length and are in close agreement with the published data on quantum chemical calculations. By the nature of decomposition in the solid state, these compounds differ significantly from FOX-7. This difference is due to the fact that the condensed products of their decomposition are not solid but liquid compounds.