1,4-二氨基-3,6-二硝基吡唑[4,3-c]并吡唑的制备及热分解机理

Preparation and Thermal Decomposition Mechanism of 1,4-Diamino-3,6-dinitropyrazolo[4,3-c]pyrazole

以3,6-二硝基吡唑[4,3-c]并吡唑(DNPP)为原料,经N-胺化反应合成了1,4-二氨基-3,6-二硝基吡唑[4,3-c]并吡唑(DADNP),采用红外光谱、核磁共振(1H NMR、13C NMR)、质谱及元素分析等手段表征了化合物结构;利用差示扫描量热仪(DSC)、热重仪(TG)、固相原位热红外检测仪(RSFTIR)、热重-质谱联用技术(TG-MS)等热分析方法研究了DADNP的热分解过程和机理,结果表明,DADNP热分解反应的活化能和指前因子分别为166.45 kJ·mol^-1和1016.53 s^-1。DADNP的热分解过程主要包含两个阶段,第一阶段分别在电离源或加热条件下,DADNP分子中C─NO2首先发生断裂,生成NO2小分子;第二阶段是吡唑并吡唑环的进一步破裂及二次氧化反应,生成HCN、N2H2等小分子。

1,4-Diamino-3,6-dinitropyrazolo[4,3-c]pyrazole(DADNP)was synthesized by N-amination reaction,and its struc-ture was characterized by NMR,IR,MS and element analysis.The thermal decomposition kinetics and mechanism were studied by means of different heating rate differential scanning calorimetry(DSC),rapid-scan fourier transform infrared spectroscopy(RSFTIR)and thermogravimetry-mass spectrometer(TG-MS)coupling technique.The results show that the apparent activation energy and pre-exponential constant of the exothermic decomposition reaction of DADNP obtained by Kissinger method are 166.45 kJ·mol-1,1016.53 s-1.The decomposition of DADNP includes two stages,which begins with the rupture of C─NO2 with subsequent loss of NO2 under electron impact and heating condition,respectively.In the first stage of decomposition,the rup-ture of one C─NO2 and one pyrazole ring in DADNP molecule with the release of NO2 and N2H2 occur under electron impact condition,whereas the homolysis of two C─NO2 bonds occur with the loss of two molecular NO2 under heating condition.