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-NO2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-dinitroethylene (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 energies 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 activation energies of the nitro-nitrite isomerization.The catalytic cracking reaction of FOX-7 was catalyzed by radicals.
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