OxoMn(Salen)与取代乙烯的环氧化反应机理的理论研究  

Theoretical study on the epoxidation reaction mechanism between substituted ethylenes and the OxoMn(Salen)complex

作　　者：王长生[1] 汤立鹏[1] 曲威[1] 李书实[1] 赵明[1] 张丹[1] 

机构地区：[1]辽宁师范大学化学化工学院,辽宁大连116029

出　　处：《辽宁师范大学学报（自然科学版）》2010年第3期335-338,共4页Journal of Liaoning Normal University:Natural Science Edition

基　　金：国家自然科学基金项目(20973088)

摘　　要：使用B3LYP方法研究了OxoMn(Salen)与取代乙烯CH2=CHR(R=H,Me,NO2,CF3)的环氧化反应机理.结果表明:OxoMn(Salen)与取代乙烯的反应不可能经由协同反应通道完成;由于第一过渡态的相对Gibbs自由能太高,单重态OxoMn(Salen)与取代乙烯的反应也不可能经由分步反应通道完成;三重态和五重态OxoMn(Salen)与取代乙烯的反应可以经由分步反应通道2步完成,并且第1步是反应的决速步骤.研究结果还表明,取代基对第一过渡态的相对Gibbs自由能影响不大.Theoretical studies based on a hybrid density functional theory（B3LYP）were carried out to explore the epoxidation reaction mechanism between substituted ethylenes CH2=CHR（R=H,Me,NO2,CF3）and the OxoMn（Salen）complex.Calculation results show that the reactions could not follow through a concerted mechanism.The reactions in the singlet energy hyper surface could not accomplish through a stepwise pathway either,owing to the high relative Gibbs free energies in the first transition states process.The stepwise pathway is feasible for both the triplet and quintet reactions in which the first step is rate determining.Calculation results also show that the substituent has little effect on the epoxidation reaction barrier.

关 键 词：环氧化反应 取代乙烯 相对Gibbs自由能 

分 类 号：O641.121[理学—物理化学]