带电粒子对FOX-7裂解通道影响的密度泛函研究

D ensity Functional Study of the Effect of Charged Particles on FOX-7 D issociation Channels

为研究带电粒子(H_3O^+,OH^-,NO_2^+ and NO^+)对1,1-二氨基-2,2-二硝基乙烯(FOX-7)裂解通道的影响,采用密度泛函理论的B3LYP、B3PW91和PBE0泛函理论在6-31++G(d,p)基组下优化出了H_3O^+,OH^-,NO_2^+ 和 NO^+分别与FOX-7的复合体,从成键方式和静电势变化的角度分析了复合方式。在相同水平下,计算了各复合体不同裂解通道的活化能,并基于键长、键级、成键方式等电子结构参数的变化分析了活化能变化的本质。结果表明,在B3LYP/6-31++G(d,p)水平上,OH^-使两种构型C—NH_2键的离解能分别下降了260.7 k J·mol-1和74.3 k J·mol-1,H_3O^+,NO_2^+ 和 NO^+使C—NO_2键的离解能下降44~260 k J·mol-1,带电粒子使大部分复合体C—C键的离解能提高,但对硝基异构的活化能影响甚微,由过渡态分析可知,这源于硝基异构的过渡态具有的极其相似的几何构型。四种带电粒子都扰乱了单分子FOX-7相对稳定的结构,降低了FOX-7后续裂解的能垒,影响了FOX-7裂解中后期自加速反应的进程。

To investigate the effects of charged particles （H3O＋, OH-, NO2＋ and NO＋） on the dissociation channel of 1,1-diamino-2,2- dinitroethylene（ FOX-7）, the complexes of H3O＋, OH-, NO2＋ and NO＋ respectively with FOX-7 were optimized using B3 LYP, B3 PW91 and PBE0 functional theory of density functional theory in 6-31 ＋＋G（d, p） basis sets. The composite mode was analyzed from bonding styles and electrostatic potential. At the same level, the activation energies of the different dissociation channels of the complexes were calculated ,and the nature of change in activation energies were analyzed based on the changes of the electronic structure parameters such as bond length, bond order and bonding styles. Results show that at B3LYP/6-31 ＋＋G（d, p） level, OH- makes the dissociation energies of the two configurations of C-NH2 bond decrease by 260.6 kJ · mol-1 and 74.3 kJ · mol-1 , respectively. H3O ＋, NO2＋ and NO＋ make the dissociation energies of C--NO2 bond decrease by 44-260 kJ · mol-1. The charged particles make the dissociation energy of C--C bond of the most complexes increase, but have little effect on the activation energy of nitro isomerism. By the analysis of the transition state, ones may know that this is due to the extremely similar geometry of the transition state of the nitro isomerism. The four kinds of charged particles disturb the relatively stable structure of FOX-7, reduce the energy barrier of the subsequent dissociation, and affect the self-acceleration reaction process in the late stage of FOX-7 dissociation.