中文摘要：

利用密度泛函理论研究了N′-苯亚甲基-苯并酰肼气相高温分解生成苯腈和苯甲酰胺的反应机理．首先用B3LYP／6．31G（d，p）方法优化反应中反应物、过渡态、中间体及产物的几何构型，然后通过振动分析确认了过渡态的结构，并通过内窠反应坐标方法（IRC）确认能量最低的反应途径．报道了3条可能的反应通道，包括1条直接协同高温分解反应和2条先成环后协同高温分解反应途径，其中直接协同高温分解反应由于能垒低，因此发生的几率较大．

英文摘要：

The gas-phase pyrolytic decomposition mechanisms of N′-benzylidene-benzohydrazide with the production of benzene nitrile and benzamide were studied by density functional theory. The geometries of the reactant, transition states, intermediates and products were optimized at the B3LYP/6-31G （d, p） level. Vibration analysis was carded out to confirm the transition state structure, and the intrinsic reaction coordinate （IRC） method was performed to search the minimum energy path. Three possible reaction channels are shown, including one concerted reaction of direct pyrolytic decomposition and two indirect channels in which the reactant first becomes a ring-like intermediate, followed by concerted pyrolytic decomposition. The concerted reaction of direct pyrolytic decomposition has the lowest activation barrier among all the three channels and therefore it occurs more often than the others.