氮杂炔正离子与环烯反应的机理及取代基效应  

The influence of substituents on nitriliums with bicycle[2.2.1]-hept-2-ene

作　　者：林雪飞[1] 孙成科[1] 

机构地区：[1]曲靖师范学院化学与生命科学系,云南曲靖655011

出　　处：《化学研究与应用》2007年第8期872-876,共5页Chemical Research and Application

基　　金：云南省教育厅科学研究基金资助(06Y064A);云南省教育厅教学科研带头人项目资助(200401)

摘　　要：用DFT方法研究了氮杂炔正离子[R-C≡N-CH3]+与二环[2,2,1]-2-庚烯的反应机理。所有几何构型用B3LYP/6-31G**基组进行优化,过渡态通过振动分析和内聚反应坐标进行了确认。并在相同基组上研究了当R为不同取代基时的反应变化规律。结果表明该反应为环加成反应,有两条反应途径,产物主要通过能量较低的过渡态TSa生成。当取代基为支链烷烃基团时,反应位垒较大;取代基为直链烷烃基团和苯环时,反应较易进行。The mechanisms on addition reactions of nitrilium[ R-C≡ N-CH3 ]^＋ with bicycle[ 2. 2. 1 ]-hept-2-ene have been studied using the density function theory method. M1 geometries were optimized at the B3LYP/6-31G ＊ ＊ level, the transition states have further been confirmed by intrinsic reaction coordinates （IRC）and characterized by the number of imaginary vibrational frequency, and the energies of the stationary points in the teaction processes were calculated. The influence of different substituents on the addition reaction has been also discussed. The obtained results show that the titled reaction is a addition reaction, which consists of two similar parallel reactions Path 1 and Path 2, and generate the product Pa and Pb via TSa and TSb, respectively. The reaction process of the Path 1 is much more favorable than that of the Path 2. The energy barrier of reaction is higher when the substituent is branchalkyl, and the energy barrier for straight-alkyl and phenyl is low so that the reactions take place easily.

关 键 词：氮杂炔正离子 二环烯 加成反应 取代基 

分 类 号：O641.121[理学—物理化学]