卤代烷的SN_2反应的研究  

Study on SN_2 reaction of alkyl halide

作　　者：涂文通 干作飞 赵丹[1] 

机构地区：[1]广西师范学院化学与材料科学学院,广西南宁530001

出　　处：《广西师范学院学报（自然科学版）》2015年第3期50-59,共10页Journal of Guangxi Teachers Education University(Natural Science Edition)

摘　　要：双分子亲核取代(SN2)反应是重要的基本有机反应之一,其中电子从亲核基团向离去基团的转移发挥着关键作用。利用密度泛函理论(DFT)计算方法分别在B3LYP/6-311++G(d,p)以及B3LYP/LanL2DZ水平上对SN2反应进行了研究,计算出了反应物﹑中间态或复合物﹑过度态的能量以及活化能和优化结构数据﹑Mulliken电荷布居﹑NBO分析的键级﹑SCAN扫描的势能面等。结果表明介电常数﹑离去基团的碱性﹑支链基团(空间位阻效应和推吸电子效应)﹑溶剂效应等都对SN2反应有影响。本文以简单经典反应为计算依据,得出计算的方法和思路,为以后的复杂反应提供理论指导。bimolecular nucleoplilic-substitution(SN2) reaction is one of the basic organic reactions,the electron transfer from the parent group to the leaving group plays a key role.The SN2 reaction at B3LYP/6-311++G(d,p)and B3LYP/LanL2 DZ levels were studied by using density functional theory(DFT).The energy of reactants,the intermediate state or complex and the transition state are calculated,and activation energy and optimized structure data,Mulliken charge distribution,NBO analysis,SCAN scanning potential energy surface,etc.The results show that the permittivity,the basicity of the leaving group,branched groups(steric effect and push-pull electron effect)and the solvent effect have the effect on the SN2 reaction.This article based on the simple classical reaction,the method and the method of calculation are obtained,which can provide the guidance for the complicated reaction in the future.

关 键 词：SN2反应 密度泛函理论(DFT) 过度态 活化能 

分 类 号：O622.2[理学—有机化学]