摘要
用量子力学方法对偶氮异丁腈(AIBN)分解反应的机理进行了系统的理论研究.应用密度泛函理论在B3LYP/6-311G*,B3LYP/6-311+G*和BHandH/6-31+G**水平上对此反应过程中所涉及的反应物、过渡态、中间体、复合物和产物的几何结构和能量进行优化计算,并给出了反应详细的势能面信息和机理解析.结果表明,偶氮异丁腈在基态下采取两键(三体)同步解离的模式进行自由基热分解反应,即Me2(CN)C-N=N-C(CN)Me2→2Me2(CN)C.+N2;在三态(诱导激发)下,则进行两键(三体)异步解离,即Me2(CN)CN=N—C(CN)Me2→Me2(CN)—CN=N…C(CN)Me2→2Me2(CN)C.+N2.计算的活化能与实验结果吻合.
The decomposition mechanisms of azoisobutyronitrile （AIBN） have been investigated systematically. The density function theory B3LYP/6 - 311G^＊ , B3LYP/6 - 311 ＋ G^＊ and BHandH/6 - 31 ＋ G^＊ ＊ method was employed to optimize the geometric parameters of reactant, transition state, possible intermediates and products based on the detailed potential energy surfaces （PES） scanned with AM1. And the reaction mechanism and reason has been also analyzed theoretically. The results show that the decomposition of azoisobutyronitrile is a twobond （three body） synchronous cleavage proceeding in ground state Me2 （CN）C - N = N - C（CN） Me2→2Me2 （CN）C· ＋ N2 ;and is a two - bond asynchronous cleavage proceeding wile in the triple state Me2 （CN）CN = N- C（CN）Me2→Me2 （CN）-CN = N-C（CN）Me2→2Me2 （ CN）C· ＋ N2. Our calculations rationalize and verify all the experimental facts.
出处
《曲靖师范学院学报》
2005年第6期1-8,共8页
Journal of Qujing Normal University
基金
云南省教学科研带头人基金资助项目(200401)
关键词
偶氮异丁腈
分解反应
密度泛函(DFT)
azoisobutyronitrile（AIBN）
decomposition
density funtion theory（DFT）
