1,5-二氨基四唑的异构化合成动力学

Theoretical Studies on Kinetics of Isomerization Reaction for 1,5-Diamino-tetrazole

用密度泛函方法，计算研究1，5-二氨基四唑（DAT）的电子结构及异构化反应机理。在B3LYP／6—311G水平下，对涉及反应各驻点的几何结构、振动频率、自然键轨道、以及零点能（ZPE）进行了计算；用内禀反应坐标理论（IRC）获得反应的最小能量路径（MEP），在耦合簇理论的CCSD（T）方法下计算单点能得到了反应的最小势能曲线；并且用传统过渡态理论（TST）、Eckart隧道校正理论（TST／Eckart）和变分过渡态理论（CVT），计算了200～1000K的反应速率常数。计算结果表明，DAT分子中的N（4）和N（9）易参与金属原子配位，形成一系列以DAT为配体的配位化合物。异构化合成DAT反应为叠氮基关环机理，气态情况下该反应为放热且自发反应，反应活化能较低。

The electronic properties of 1 , 5-diamino-tetrazole（DAT） and isomerization reaction kinetics were studied based on densi- ty functional theory. The geometry structure, vibration frequencies, natural bonding orbital, and zero point energy （ZPE） of station- ary points involved in the reaction was calculated at B3LYP/6-311G level of theory. The intrinsic reaction coordinate theory （IRC） was used to obtain the minimum energy path （MEP）. The reaction potential energy curve was obtained by calculating the single point energy with CCSD （T） method. The rate constants are evaluated from 200 to 1000 K using transition state theory （TST）, TST/ Eckart and Canonical variational transition state theory （CVT）. Results show that N （4） and N （9） in DAT molecule participate easily in coordination with metal atoms, forming a series of coordination compounds. The isomerization reaction for DAT displays azide- cyclization mechanism. At gaseous case, the reaction is exothermic and spontaneous, with lower reaction activation energy.