MnSalen(O)(Cl)氧化CH_2=CHR(R=H,Me,Ph)环氧化反应的理论研究——取代基R对活化吉布斯自由能的影响  

Theoretical study on the epoxidation of the substituted ethylene catalyzed by MnSalen(O)(Cl)——The effect of the substituted groups on the activation free energies

作　　者：王长生[1] 张丹[1] 高坤[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）》2008年第2期185-188,共4页Journal of Liaoning Normal University:Natural Science Edition

基　　金：国家自然科学基金资助项目(20573049);辽宁省科学技术基金资助项目(2004C019;20060469)

摘　　要：使用B3LYP方法研究了三线态Salen-Mn(V)氧化物1催化氧化烯烃CH2=CHR(R=H,Me,Ph)的环氧化反应中不同取代基对反应势垒的影响.优化得到了相关反应物、中间体、过渡态和环氧化产物即环氧烷烃和Salen-Mn(Ⅲ)复合物的结构.计算了三线态各驻点上吉布斯自由能值.研究结果显示,所有反应均为放热反应,反应势垒都很小,说明这些反应在室温下都很容易发生;当R=Me时,反应的活化吉布斯自由能最低,当R=H时,反应的活化吉布斯自由能最高.B3LYP density functional calculations were carried out to study the epoxidation of substituted ethylene CH2 =CHR（R= H,Me,Ph）, where a model catalyst with chloride as oxygen containing counter ligand, MnSalen（O）（Cl）, was employed. The optimal structures of the reactants, intermediates, transition states, and products were obtained. The Gibbs free energies were calculated and the effects of the substituents on the barriers was therefore illustrated. Calculations results show that all three reactions are exothermic, and reaction barriers are small, so all the reactions will steadily take place at the room temperature. The activation free energy is smallest for R= Me, while it is largest for R=H.

关 键 词：MnSalen(O)(Cl) B3LYP方法 取代乙烯 

分 类 号：O641.121[理学—物理化学]