硅烯及其卤代物与苯环加成反应机理的研究  

Theoretical Study on the Mechanism of Cycloaddition Reaction Between Silylene,Halogeno-silylene and Benzene

作　　者：于海彬[1] 王玉芝[1] 张萌[1] 卢秀慧[1] 

机构地区：[1]济南大学化学化工学院,山东济南250022

出　　处：《济南大学学报（自然科学版）》2005年第4期305-308,共4页Journal of University of Jinan(Science and Technology)

基　　金：山东省自然科学基金资助项目(Y2002B07)

摘　　要：用量子化学方法分别研究了单重态硅烯、氟代硅烯、氯代硅烯与苯环加成反应的机理,采用HF/3-21G*方法计算了势能面上各驻点的构型参数、振动频率和能量。研究结果表明,硅烯、氟代硅烯、氯代硅烯与苯的环加成反应具有相同的反应途径,该途径均由两步组成:(1)硅烯、氟代硅烯、氯代硅烯与苯反应分别生成中间体INT1I、NT2I、NT3,它们均是无势垒的放热反应,放出的热量分别为18.9,29.1,31.5kJ.mol-1;(2)中间体INT1I、NT2I、NT3分别经过渡态TS1、TS2和TS3异构化为产物P1、P2和P3,其势垒分别为93.8,230.3和205.2kJ.mol-1。硅烯、氯代硅烯和氟代硅烯在与芳香族化合物环加成反应中的反应活性次序为:硅烯>氯代硅烯>氟代硅烯。The mechanisms of cycloaddition reactions between singlet silylene,difluosilylene,dichlorosilylene and benzene have respectively been investigated with HF/3-21G* method.Geometry optimization,vibrational analysis and energies have been done for the involved stationary points on the potential energy surface.The results show that the cycloaddition reactions of silylene,difluosilylene,dichlorosilylene and benzene have the same reaction paths,which consist of two steps:(Ⅰ)silylene,difluosilylene, dichlorosilylene and benzene form the intermediates INT1,INT2 and INT3,which are barrier-free exothermic reactions of 18.9,29.1 and 31.5?kJ/mol,respectively; (Ⅱ) Intermediates INT1,INT2 and INT3 isomerize to products P_1,P_2 and P_3 via transition states TS1,TS2 and TS3,in which the energy barriers are 93.8,230.3 and 205.2?kJ/mol,respectively.The order of reaction activity of cycloaddition reactions of silylene,difluosilylene,dichlorosilylene and aromatic compounds is silylene>dichlorosilylene>difluosilylene.

关 键 词：硅烯 苯 环加成反应 势能面 

分 类 号：O641[理学—物理化学]