硫代草酸异构体结构及异构化反应机理的理论研究  

Theoretical Study on the Structures and Isomerization of HO(S)CC(S)OH

作　　者：靳玲侠[1] 吕梦丹[1] 闵锁田[1] 张强[1] 赵蔡斌[1] 卢久富[1] 王令[1] 魏雅雯[2] 

机构地区：[1]陕西理工大学化学与环境科学学院陕西省催化基础与应用重点实验室,汉中723001 [2]长安大学出版科学研究所,西安710064

出　　处：《化学通报》2016年第12期1184-1188,共5页Chemistry

基　　金：国家自然科学基金项目(21603133);陕西省教育厅专项科研基金项目(16JK1134);中央高校基金资助项目(310850160322);陕西理工大学科研基金资助项目(SLGQD14-10;SLGKYQD2-13)资助

摘　　要：采用量子化学CBS-QB3组合方法对硫代草酸可能存在的异构体构型及异构体间相互转化机理进行了详细计算研究,分别得到11种稳定结构及12种异构化过渡态。其中硫代草酸异构体的相对稳定性顺序为M11>M7>M10>M1>M9>M6>M2>M3=M4>M5,不稳定异构体M5极易向稳定异构体转化。异构体M6向M11转化仅需越过1.92k J·mol-1的能垒,且放出49.04k J·mol-1能量,因此M6向M11的转化是H迁移异构化反应的主通道。The stability and isomerization mechanisms of HO （S）CC （S）OH have been investigated by the CBS- QB3 composite approach. Eleven isomers and twelve transition states were obtained and the possible reaction pathways were probed. The results indicated that the order of stability is M11 〉 M7 〉 MIO 〉 M1 〉 M9 〉 M6 〉 M2 〉 M3 = M4 〉 M5. The activation free energy associated with the C-C bond rotation paths are all small, and they are easily converted into the O-H bond rotation isomers. In addition, the isomerization of M6 to Mll is most favorable both thermodynamically and kinetically in all isomerizations, which should be the dominant process.

关 键 词：硫代草酸 H迁移 异构化反应 

分 类 号：O623.8[理学—有机化学] O621.1[理学—化学]