H^+、NH_4^+对HMX的N—NO_2键解离能的影响  

Effect of H^+ and NH_4^+ on the N-NO_2 Bond Dissociation Energy of HMX

作　　者：王罗新[1] 刘勇[1] 庹新林[1] 李松年[1] 王晓工[1] 

机构地区：[1]清华大学化学工程系,高分子研究所,北京100084

出　　处：《物理化学学报》2007年第10期1560-1564,共5页Acta Physico-Chimica Sinica

基　　金：国家安全重大基础研究项目资助

摘　　要：采用密度泛函理论的B3P86/6-31G**方法,优化了β-HMX环四甲撑四硝胺及其与H+、NH4+分别形成的复合物的稳定结构,计算了β-HMX以及复合物中最弱的N—NO2键解离能.结果发现,HMX与H+、NH4+形成复合物后,使HMX的构型产生较大变化;与H+结合后,HMX的一个N—NO2键显著伸长,键级变小;但与NH4+形成复合物后,HMX中键级最小的N—NO2键长变化不大.键解离能计算表明,同β-HMX相比,与H+形成的两种复合物中N—NO2键解离能分别降低了近20和82kJ·mol-1,而HMX与NH4+形成的复合物中N—NO2键解离能仅降低了约8kJ·mol-1,表明H+对β-HMX的N—NO2键的初始热裂解反应有促进作用,而NH4+影响不明显.The structure of β-HMX （β-octahydro-1, 3, 5, 7-tetrartitro-1, 3, 5, 7-tetrazocine） and several complexes with H^＋ or NH^＋ were optimized using the density functional theory （DFT） at the B3P86/6-31G^＊ ＊ level. Meanwhile, the bond dissociation energies of the weakest N--NO2 for β-HMX and the complexes were obtained by the same calculation method. It was found that the geometrical configuration of the HMX in the complexes differed significantly from that of β-HMX. On the other hand, one of the N--NO2 bonds of HMX was activated due to the combination of H^＋ with HMX, but this activation was unobvious for the complexes with NH 2. The N--NO2 bond dissociation energies of two complexes with H^＋ decreased about 20 and 82 kJ ·mol^-1, respectively, in comparison with that of β-HMX. However, the N--NO2 bond dissociation energy for the complex with NH4^＋ decreased only about 8 kJ·mol^-1. It indicated that the H^＋ could promote the initial thermal decomposition of N--NO2 bond of β-HMX, but this initial decomposition was slightly inβuenced by NH4^＋.

关 键 词：HMX 键解离能 热裂解能 密度泛函理论 

分 类 号：O641.1[理学—物理化学]