CH2O＋O[^3P]→CHO＋OH反应途径和变分速率常数  

The Reaction Path and Variational Rate Constant of the Hydrogen Abstraction Reaction CH_2O+O［~3P］→CHO+OH

作　　者：李会英[1] 冯文林[1] 冀永强[1] 徐振峰 雷鸣[1] 

机构地区：[1]北京化工大学应用化学系,北京100029

出　　处：《物理化学学报》2002年第5期446-450,共5页Acta Physico-Chimica Sinica

基　　金：国家教育委员会博士点基金(1999002715)资助项目

摘　　要：采用QCISD/6-311G犤d,p犦从头算方法,优化了吸氢反应CH2O+O犤3P犦→CHO+OH的反应物、过渡态和产物的几何结构,并用QCISD(t,full)/6-311G//QCISD/6-311G方法对各驻点进行了单点校正,得出正逆反应的活化位垒分别为38.86kJ·mol-1和67.23kJ·mol-1.IRC(内禀反应坐标)分析指出,该反应是一个C-H键断裂和H-O键生成协同进行的反应,而且在反应途径上存在一个引导反应进行的振动模式,其引导反应进行s区间为-0.4～0.75(amu)1/2.在1300～2270K温度范围内运用改进的变分过渡态理论(ICVT),计算了反应速率常数,与实验结果相当一致.Using ab initio molecular orbital theory,the hydrogenion reaction CH2O+O→CHO+OH has been studied.The geometries of the reactants,transition state and products have been optimized at the QCISD/6 311G level.The forward and reverse reaction potential barriers are 38.86 kJ·mol-1 and 67.23 kJ·mol-1 respectively at the QCISD(t,full)/6 311G//QCISD/6 311G.By analyzing the changes of the generalized normal mode vibrational frequencies along the IRC,we found that the C-H bond breaking and the O-H bond forming took place as a concerted process.And there is a reactive vibrational normal mode which leads to the process of reaction from reactants to products.At the temperature range of 1 300～2 270 K,the forward and reverse reaction rate constants obtained by using the improved canonical variational transition state theory (ICVT),are consistent with the experimental values.

关 键 词：反应途径 甲醛 三线态氧 速率常数 从头算法 变分过渡态理论 反应动力学 

分 类 号：O643.11[理学—物理化学]