初始裂解产物对FOX-7裂解通道影响的理论研究

Theoretical Study of the Effect of Initial Products on FOX-7 Dissociation Channels

为研究裂解过程中生成的自由基(·H、·OH和·NO)对尚未裂解的1,1-二氨基-2,2-二硝基乙烯(FOX-7)各裂解通道的影响,采用密度泛函理论PW6B95-D3方法,结合def2-TZVP基组和def2-TZVP/J辅助基组在ORCA程序中优化出了·H、·OH、·NO分别与FOX-7的复合体。为判断自由基与FOX-7的复合方式,采用AIM理论计算了各复合体电荷密度的拉普拉斯值(Laplacian)。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,自由基的存在使C—NO_2键的离解能(除NO_01外)降低4.1~138 kJ·mol^(-1);但对硝基异构的活化能影响不大。自由基的生成引发了FOX-7的自加速裂解反应。

To investigate the effect of radicals that generated in the reaction process on 1 ,1-diamino-2,2-dinitro- ethylene （ FOX-7 ） dissociation channels, geometries and electronic structures of the complexes which were composed of radicals and FOX-7 have been calculated. The PW6B95-D3 functional were used in conjunction with basis set def2-TZVP and auxiliary basis sets def2-TZVP/J in ORCA program for these calculations. The value of the Laplacian are calculated by using the quantum theory of atoms-in-molecules to analyze intermolecular interaction. The activation energies of the different dissociation channels of each complexes were calculated and the origin of the activation ener-gies change were analyzed from bond lengths, bond orders and bonding styles. Results show that radicals reduce the dissociation energies of the C-NO2 bond （except NO_01） by 4. 1 - 138 kJ·mol^-1, but have little effect on the acti-vation energies of the nitro-nitrite isomerization. The catalytic cracking reaction of FOX-7 was catalyzed by radicals.