物理化学学报 >> 2013, Vol. 29 >> Issue (11): 2313-2320.doi: 10.3866/PKU.WHXB201310083

理论与计算化学 上一篇    下一篇

反式2-甲基-2-丁烯酸甲酯与臭氧反应机理的计算研究

张田雷1,2, 王渭娜1, 刘畅1, 吕娜1, 陈妙1, 郭莎1, 王文亮1   

  1. 1 陕西师范大学化学化工学院, 陕西省大分子科学重点实验室, 西安 710062;
    2 陕西理工学院化学与环境科学学院, 陕西汉中 723001
  • 收稿日期:2013-07-09 修回日期:2013-10-07 发布日期:2013-10-30
  • 通讯作者: 王文亮 E-mail:wlwang@snnu.edu.cn
  • 基金资助:

    国家自然科学基金(21173139)及陕西师范大学国家级大学生创新性实验计划(1110718008)资助项目

Computational Study of the Reaction Mechanism and Kinetics of CH3CHC(CH3)COOCH3 Ozonolysis

ZHANG Tian-Lei1,2, WANG Wei-Na1, LIU Chang1, LU Na1, CHEN Miao1, GUO Sha1, WANG Wen-Liang1   

  1. 1 Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710062, P. R. China;
    2 School of Chemical & Environment Science, Shaanxi University of Technology, Hanzhong 723001, Shaanxi Province, P. R. China
  • Received:2013-07-09 Revised:2013-10-07 Published:2013-10-30
  • Contact: WANG Wen-Liang E-mail:wlwang@snnu.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (21173139) and Student Innovation Foundation of Shaanxi Normal University, China (1110718008).

摘要:

采用G3B3方法构建反式2-甲基-2-丁烯酸甲酯与O3反应体系以及后续Criegee 自由基有、无水分子参与下异构化反应的势能面剖面. 结果表明, 反式2-甲基-2-丁烯酸甲酯与O3反应首先生成一个稳定的五元环中间体, 此中间体按断键位置不同后续裂解反应存在两条路径, 分别生成产物P1(CH3CHOO+CH3OC(O)C(CH3)O)和P2(CH3CHO+CH3OC(O)C(CH3)OO). 利用经典过渡态理论(TST)并结合Wigner 矫正模型计算了200-1200K 温度区间内标题反应的速率常数kTST/W. 计算结果显示, 294 K 时, 该反应速率常数为7.55×10-18 cm3·molecule-1·s-1, 与Bernard 等对类似反应所测实验值非常接近. 生成的Criegee 自由基(CH3CHOO 和CH3OC(O)C(CH3)OO)可分别与水分子发生α-加成及β-氢迁移反应, 其中Criegee 自由基与水的α-加成反应较其与水的β-氢迁移反应具有优势. 另外与无水分子参与CH3CHOO和CH3OC(O)C(CH3)OO异构化反应相比,水分子的参与使得异构化反应较为容易进行.

关键词: 2-甲基-2-丁烯酸甲酯, 臭氧, 密度泛函理论, 反应机理, 速率常数

Abstract:

The reaction mechanism for the ozonolysis of trans-CH3CHC(CH3)COOCH3 as well as the isomerization reaction of CH3CHOO and CH3OC(O)C(CH3)OO) without and with a water molecule were investigated at the G3B3 level. The profile of the potential energy surface (PES) was constructed. Ozone adds to trans-CH3CHC(CH3)COOCH3 via a cyclic transition state to produce a highly unstable primary ozonide that can decompose readily to form P1(CH3CHOO + CH3OC(O)C(CH3)O) and P2(CH3CHO + CH3OC(O)C(CH3)OO) because the bond breaks in different positions. The total rate constants over the temperature range of 200-1200 K are obtained using the conventional transition state theory with Wigner tunneling correction. The calculated rate constant is 7.55×10-18 cm3·molecule-1·s-1 at 294 K, in good agreement with previous experimental data for similar reactions. The isomerization reaction of CH3CHOO and CH3OC (O)C(CH3)OO) with a water molecule can occur via α-addition process and β-hydrogen transfer mechanism. The former is more favorable than the latter. Compared with the naked isomerization reactions of CH3CHOO and CH3OC(O)C(CH3)OO), the presence of water molecules makes isomerization reactions much easier.

Key words: CH3CHC(CH3)COOCH3, O3, Density functional theory, Reaction mechanism, Rate constant

MSC2000: 

  • O641