【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.更多还原

【Abstract】 The structure of β-HMX ( β-octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine) and several complexes with H+ or NH+4 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+4. 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 NH+4 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 influenced by NH+4.更多还原