化学学报 ›› 2012, Vol. 70 ›› Issue (11): 1245-1249.DOI: 10.6023/A1201134 上一篇    下一篇

研究论文

Fe2+活化CH3X (X=H, Cl)中C—H, C—Cl 键的理论研究

孙小丽, 李吉来, 黄旭日, 孙家锺   

  1. 吉林大学理论化学研究所 理论化学国家重点实验室 长春 130023
  • 收稿日期:2012-01-13 修回日期:2012-02-28 出版日期:2012-06-14 发布日期:2012-03-29
  • 通讯作者: 李吉来, 黄旭日 E-mail:jilai@jlu.edu.cn
  • 基金资助:

    国家自然科学基金(Nos. 21103064, 21073075 和21173097)、教育部博士点基金(No. 20100061110046)、吉林大学理论化学国家重点实验室专项基金和吉林大学基本科研业务费(Nos. 421010061439, 450060445067).

A Theoretical Study on Activation of C—H and C—Cl Bonds in CH3X (X=H, Cl) by Fe2+

Sun Xiaoli, Li Jilai, Huang Xuri, Sun Chiachung   

  1. State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023
  • Received:2012-01-13 Revised:2012-02-28 Online:2012-06-14 Published:2012-03-29
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Nos. 21103064, 21073075, 21173097), Research Fund for the Doctoral Program of Higher Education of China (No. 20100061110046), the Special Funding of State Key Laboratory of Theoretical and Computational Chemistry, Jilin University and Basic Research Fund of Jilin University (Nos. 421010061439, 450060445067).

采用密度泛函理论(DFT)详尽地研究了Fe2+与CH3X (X=H, Cl)的反应机理. 结果表明在所有通道中, 反应4 的H 提取能垒最低(ΔGa=0.23 kcal/mol), 氧化插入机制和SN2 取代机制没有竞争性. 详尽的电子结构分析表明由于金属3d 与底物的σC—X* 可以最好的重叠, 从而Fe2+从前端进攻C—X 键有利于反应. 该研究揭示了其微观本质, 为Fe2+活化C—X 键等相关研究提供理论线索和依据.

关键词: SN2, 插入, 抽提, 反应机制, 活化能, 电子结构

The reactions of Fe2+ with CH3X (X=H, Cl) have been studied by density functional theory method detailedly. The results demonstrated that the H abstraction in Eq. 4 can proceed via the lowest activation barrier (ΔGa=0.23 kcal/mol) in all feasible pathways. However, the mechanisms of oxidative insertion and the SN2 substitution are not competitive because of thermodynamic factors. The electronic structure analysis suggests that the overlap between metal 3d orbital and substrate σC—X* results in the preference of Fe2+ front side attack on the C—X bond. This study is expected to shed light on the nature of the title reactions and provide theoretical clues and foundation for future research.

Key words: SN2, insertion, abstraction, reaction mechanism, activation barrier, electronic structure