Crystal Structure and Thermal Behavior of a Novel Cocrystal Consisting of 3,3？-Dinitrimino-5,5？-Bis（1H-1,2,4-triazole）,H_2O and （CH_3）_2SO

A typical nitroimine bistriazole (DNABT) was synthesized with high yield (90.4%) by nitration reaction from DABT in HNO3 and NH4NO3. Furthermore, a novel cocrystal (1) consisting of DNABT, H2O and DMSO in a 1:2:2 molar ratio was analysized on the crystal structure. Cocrystal 1 crystallizes in the triclinic system, space group P1 with a = 6.3124(18), b = 8.233(2), c = 9.775(3) A, β = 98.326(4)°, V = 481.59(74) A, Z = 2, Dc = 1.55 g/cm, F(000) = 234, μ = 0.337 mm, S = 1.078, the final R = 0.0609 and wR = 0.2743. Additionally, the crystal structure is built up by four strong and seven weak hydrogen bonds. And the hydrogen bond network contributes to the stability of DNABT molecule. Typical TGA and DSC curves indicate the cocrystal 1 includes one endothermic and one exothermic decomposition processes, and the peak temperature at each process is 164.0 and 245.0 C. The nonisothermal decomposition kinetics analysis was performed by means of the Kissinger and Ozawa methods. The apparent activation energy (Ea) and pre-exponential factor (A) of the two decompositions are 96.0 kJ·mol, 10 s and 215.8 kJ·mol, 10 s, respectively. Keyword: energetic material, cocrystal, 3,3 -dinitrimino-5,5 -bis(1H-1,2,4-triazole), thermal behavior, decomposition kinetics; DOI: 10.14102/j.cnki.0254-5861.2011-0883