Mo的亚硝酰基配合物催化的亚胺氢化反应机理的研究  

Study on the mechanism of imine hydrogenation catalyzed by a molybdenum nitrosyl complex

作　　者：张红红[1] 张岩[1] 杨仲年[1] 

机构地区：[1]滨州学院化学工程系,山东滨州256600

出　　处：《计算机与应用化学》2014年第6期766-768,共3页Computers and Applied Chemistry

基　　金：滨州市科技发展计划项目(2013ZC0703);滨州学院科研基金资助项目(2010Y04;BZXYG1210)

摘　　要：采用密度泛函理论(DFT)的B3LYP方法,对过渡金属Mo的二膦亚硝酰基氢化物[Mo(dimpp)(NO)(CO)_2(H)](MoH,dimpp=1,3-二(二甲基膦基)丙烷)催化的N-苯亚甲基甲胺(BIMA)氢化的反应机理进行了理论研究。Mo原子基于LANL2DZ基组,其它原子基于6-31+G(d,p)基组,对反应势能面上各稳定点和过渡态的进行了几何构型优化和振动频率分析。计算结果表明,该催化反应通过质子-负氢转移的离子氢化机理进行。催化循环由MoH质子化生成酸性η~2-H_2配合物MoHH开始,分3步进行:(1)η~2-H_2配体上的质子转移到亚胺的N原子上生成亚胺正离子;(2)负氢转移到亚胺正离子的碳原子上,生成产物胺;(3)氢分子与金属中心Mo配位生成MoHH。这3个步骤的活化能分别为5.7,8.1和3.6 kcal.mol^(-1)。The mechanism of catalytic hydrogenation of N-benzylidenemethylamine by the molybdenum nitrosyl complex [Mo（dimpp）（NO）（COh（H）]（MoH） has been investigated by use of the B3LYP method of the density functional theory.The optimization and frequency analysis of geometries of stationary points and transition states on the energy profiles were carried out with LANL2DZ basis set for Mo and the standard 6-3 l＋G（d,p） basis set for the remaining elements.According to the computational results,the catalytic reaction proceeds through the ionic hydrogenation pathway with proton-before-hydride transfer.The catalytic cycle,which is started by the protonation of the hydride MoH forming the dihydrogen complex MoHH,can be divided into three steps：（1） the proton of H2 ligand transfers to the N atom of imine generating the iminium; （2） the hydride transfers to the C atom of irninium producing the amine; （3） the hydrogen molecule coordinates with metal center Mo and regenerates MoHH.The activation energy barriers for the three steps are 5.7,8.1 and 3.6 kcal.mol-1,respectively.

关 键 词：催化氢化 亚胺 密度泛函理论 

分 类 号：O641[理学—物理化学]