Molecular structure, thermal behavior and adiabatic time-to-explosion of 3,3-dinitroazetidinium picrate

Abstract

3,3-Dinitroazetidinium picrate (DNAZ⋅PA) was synthesized by adding 3,3-dinitroazetidine (DNAZ) to picric acid (PA) in methanol, the single crystals suitable for X-ray measurement were obtained by recrystallization at room temperature. The compound crystallises orthorhombic with space group P2 12 12 1 and crystal parameters of a = 0.7655(1) nm, b = 0.8962(2) nm, c = 2.0507(4) nm, V = 1.4069(5) nm 3, D c = 1.776 g cm −3, Z = 4, F(0 0 0) = 768 and μ = 0.166 mm −1. The thermal behavior of DNAZ⋅PA was studied under a non-isothermal condition by DSC and TG–DTG methods. The kinetic parameters of the first exothermic thermal decomposition process were obtained from analysis of the DSC and TG curves by Kissinger method, Ozawa method and the integral method. The specific heat capacity of DNAZ⋅PA was determined with a continuous C p mode of micro-calorimeter and the standard mole specific heat capacity was 436.56 J mol −1 K −1 at 298.15 K. Using the relationship of C p with T and the thermal decomposition parameters, the time of the thermal decomposition from initialization to thermal explosion (adiabatic time-to-explosion) was evaluated to be 40.7 s. The free radical signals of DNAZ⋅PA and 1,3,3-trinitroazetidine (TNAZ) were detected by electron spin resonance (ESR) technique to estimate its sensitivity.