Cl原子与CH_3COCH_2Cl反应的理论研究  

Theoretical Study on the Reaction of CH_3COCH_2Cl with Chlorine Atom

作　　者：马咏梅[1,2] 王艳丽[1] 

机构地区：[1]西北工业大学理学院应用化学系,西安710129 [2]渭南师范学院化学与生命科学学院,渭南714099

出　　处：《化学通报》2014年第6期539-544,共6页Chemistry

基　　金：西北工业大学基础研究基金项目(JC201269)资助

摘　　要：在B3LYP/6-31 G（d,p）水平上优化了Cl原子与CH3COCH2Cl反应的各驻点的几何构型,并在相同水平上通过频率计算和内禀反应坐标（IRC）分析对过渡态的结构和反应物、产物的连接性进行了验证.采用高精确模型G3MP2方法进行单点能计算,构建了反应的势能剖面.计算结果表明,标题反应有抽氢反应、加成-消除反应、取代反应3种反应机理6条反应通道.利用经典过渡态理论（TST）和正则变分过渡态理论（CVT）计算了各反应通道在200～2000 K温度范围内的速率常数,并用小区率隧道效应模型（SCT）对抽氢反应进行校正.计算结果显示,反应有一定的变分效应,计算的总反应速率常数与文献报道的实验值符合得较好,速率常数的三参数表达式为k =2.33×10-19T2.54exp（567.07/T） cm3· mol-1·s-1.The geometries, vibrational frequencies of all stationary points involved in the reaction of CHdCOCH2C1 with chlorine atom were calculated at the B3LYP/6-31G（d,p） level. Relationships of reactants, intermediates, transition states and products were confirmed by the intrinsic reaction coordinate （IRC） calculations. Potential energy surfaces were refined by single-point energy calculations at the G3MP2 level. The resuhs showed that three kinds of reaction mechanisms i.e. the H-abstraction, addition-elimination and substitution reactions were found. The rate constants of all the channels were evaluated by the classical transition state theory （TST） and the canonical variational transition state theory （CVT） over a wide temperature range of 200 - 2000 K. The small- curvature tunneling correction was calculated for the H- abstraction. The results indicated that the variational effect should be considered. The calculated rate constants were in good agreement with the experimental values reported in literatures. The fitted three-parameter expression of the total rate constants was k =2. 33× 10^-19TZ54exp（567.07/T） cm3·mol-1·s-1.

关 键 词：G3MP2 反应机理 速率常数 变分过渡态理论 

分 类 号：O643.12[理学—物理化学]