Synthesis, crystal structure and thermal behaviors of 2, 3-dihydro-4-nitro-3-(dinitromethylene)-1H-pyrazol-5-amine potassium salt [K(NNMPA)]

摘要

A novel high-energy organic potassium salt, 3-(dinitromethylene)-4-nitro-2, 3-dihydro-1H-pyrazol-5-amine potassium salt [K(NNMPA)], was first synthesized by an unexpected reaction of 1-amino-1-hydra-zino-2, 2-dinitroethylene (AHDNE) and KOH in methanol aqueous solution. K(NNMPA) was characterized by elemental analysis, IR spectra, ~(13)C NMR and single-crystal X-ray diffraction. K(NNMPA) crystallized in monoclinic system, space group P21/c with crystal parameters of a = 9.358(3) ?, b = 13.079(4) ?, c= 7.568(2) ?, β= 107.344(5)°, V= 884.2(5) ?~3, Z = 4, μ = 0.638 mm ~1, F(000) = 544 and D_(calc) = 2.03-gcm ~3. Thermal decomposition of K(NNMPA) was studied with DSC and TG-DTG methods and presents two exothermic decomposition processes. The kinetic equation of the first process obtained is dα/dT = 10~(10.42)/β 4(1-α)[-1n(1-α)] exp(-1.665 × 10~5/RT). The self-accelerating decomposition temperature (TSADT) and critical temperature of thermal explosion (Tb) of K(NNMPA) are 137.4 and 146.3 °C, respectively. K(NNMPA) exhibits lower thermal stability than K(AHDNE).