反式-1,4,5,8-四硝基-1,4,5,8-四氮杂萘烷异构体热解机理与稳定性的理论研究

运用密度泛函理论和半经验分子轨道方法，对一系列高能杂环硝胺—反式-1,4,5,8-四硝基-1,4,5,8-四氮杂萘烷异构体的热解机理和稳定性进行了系统地计算研究。在B3LYP/6-31G**和PM3水平上，分别计算了标题物的化学键离解能(BDE)和热解反应活化能(Ea)，并根据BDE和Ea数值考察了硝胺取代基对化合物稳定性和热解机理的影响；同时，还详细考察了BDE与Ea、化学键重叠布居数、前线轨道能级以及能隙之间的相关性。结果表明，由BDE、Ea和静态电子结构参数推断的标题物热稳定性和热解机理的结论基本是一致的，N-NO2键均裂是标题物的热解引发步骤，间位取代异构体较对位取代异构体稳定，而邻位取代的异构体稳定性最差。

Theoretical Studies on Thermolysis Mechanism and Stability of trans‐1,4,5,8‐Tetranitro‐1,4,5,8‐tetraazadecalin Isomers

A systematic study on the thermolysis mechanism and stability of a series of energetic cyclic nitramines, trans‐1,4,5,8‐tetranitro‐1,4,5,8‐tetraazadecalin isomers, was performed by density functional theory (DFT) and semiempirical molecular orbital (MO) calculations. Bond dissociation energies (BDE) and activation energies (E_a) of the thermolysis processes were computed at the B3LYP/6‐31G???? and PM3 levels, respectively. The effect of nitroamino groups on the thermal stability and pyrolysis mechanism of the title compounds was evaluated by the BDE and E_a. The correlations among BDE, E_a, bond overlap populations, energies of the frontier orbitals, and energy gaps were examined in detail. The results indicate that thermal stabilities and decomposition mechanisms of the title compounds derived from the BDE, E_a and static electronic parameters are basically consistent. Homolysis of the N–NO₂ bond is the initial step in the thermolysis of the title compounds, the meta‐isomers are more stable than the para‐isomers, and the ortho‐isomers are the most sensitive.