物理化学学报 >> 2011, Vol. 27 >> Issue (02): 322-328.doi: 10.3866/PKU.WHXB20110218

理论与计算化学 上一篇    下一篇

过氧化氢与苯乙烯环氧化的反应机理及溶剂效应

王志强, 孙文晶, 储伟, 余良军   

  1. 四川大学化学工程学院, 成都 610065
  • 收稿日期:2010-08-25 修回日期:2010-12-13 发布日期:2011-01-25
  • 通讯作者: 储伟 E-mail:chuwei65@yahoo.com.cn
  • 基金资助:

    国家重点基础研究发展计划项目(973) (2011CB201202)资助

Reaction Mechanism and Solvent Effects of Styrene Epoxidation with Hydrogen Peroxide

WANG Zhi-Qiang, SUN Wen-Jing, CHU Wei, YU Liang-Jun   

  1. School of Chemical Engineering, Sichuan University, Chengdu 610065, P. R. China
  • Received:2010-08-25 Revised:2010-12-13 Published:2011-01-25
  • Contact: CHU Wei E-mail:chuwei65@yahoo.com.cn
  • Supported by:

    The project was supported by the National Key Basic Research Program of China (973) (2011CB201202).

摘要:

以过氧化氢与苯乙烯环氧化为模型反应, 采用Materials Studio软件中Dmol3模块, 模拟计算了过氧化氢与苯乙烯的环氧化反应机理. 并用连续介质-类导体屏蔽模型(COSMO)研究了反应体系分别在三种质子性溶剂(水, 乙醇, 叔丁醇)中的溶剂化效应. 为研究溶剂分子直接参与反应的微观过程, 用离散介质模型模拟了单个水分子、乙醇分子和叔丁醇分子分别对反应的影响. 两种溶剂模型所得的结果一致, 叔丁醇作溶剂时反应活性最好, 乙醇次之; 质子性溶剂能够促进过氧化氢分子的异裂, 形成活性氧物种, 从而使反应能垒降低.

关键词: 密度泛函理论, 苯乙烯, 过氧化氢, 环氧化反应, 溶剂效应

Abstract:

In this paper, styrene epoxidation with hydrogen peroxide was used as a model reaction. The Dmol3 implementation in the Materials Studio Software was used to simulate the mechanism of the model reaction. Solvent effects in the reaction were also studied using the conductor-like screening model (COSMO) as a part of the continuum model in three solvents: water, ethanol, and tert-butyl alcohol. To investigate the micro-process wherein the solvent molecules react with the solute molecules directly, the discrete model was employed to simulate the impact of a single molecule of water, ethanol and tert-butyl alcohol on the reaction. Consistent results were obtained for the two different solvent models. Reaction activity was most favorable for the tert-butyl alcohol followed by ethanol. Protic solvent molecules promote the heterolytic cleavage of hydrogen peroxide and form active oxygen species, which can reduce the reaction barrier.

Key words: Density functional theory, Styrene, Hydrogen peroxide, Epoxidation reaction, Solvent effect

MSC2000: 

  • O641