偶氮桥联氮杂环化合物结构与热化学性能的DFT研究（英）

为了探寻含能化合物结构与热化学性能的关系,用密度泛函理论方法研究了15种偶氮桥联氮杂环化合物的结构与热化学性能.在B3 LYP/6-31 G(d,p)水平上,优化了它们的结构,计算了它们的熵和等压热容,通过等键反应设计,估算了它们的生成焓.结果表明,杂环上的N原子与C原子均为sp2杂环原子,所有杂环,几乎在同一平面上.化合物生成焓与氮原子数目成正比,对于氮原子数目相同的化合物,化合物的生成焓随着偶氮桥与杂环上氮原子的距离和杂环上氮原子之间的距离的增加而减小.不同温度下的等压比热容与化合物的氮含量(杂环上的氮原子数)成反比.

A Density Functional Theory Study on the Structures and Thermochemical Properties of Azo-bridged Azoles

To find the relationship between the structures and thermochemical properties of energetic compounds, the structures and thermochemical properties of 15 kinds of azo-bridged azoles were studied by density functional theory. Their structures were optimized at B3LYP/6-311+G (d,p) level, their entropies and constant-pressure specific heat capacity were calculated and their enthalpies of formation were estimated via design of the isodesmic reaction. Results show that the N atom and C atom on the heterocyclic ring are sp² heterocyclic atoms. All heterocyclic rings are nearly in the same plane. The enthalpy of formation of the compound is proportional to the number of nitrogen atom. For compounds with the same number of nitrogen atoms, the enthalpy of formation of the compound decreases with increasing the distances from the azo-bridge to nitrogen atom on heterocyclic ring and the distances between the nitrogen atoms on heterocyclic ring. The constant pressure specific heat capacity at different temperatures are inversely proportional to the nitrogen content (the number of nitrogen atom on the heterocyclic ring).