高等学校化学学报 ›› 2018, Vol. 39 ›› Issue (5): 956.doi: 10.7503/cjcu20170723

• 物理化学 • 上一篇    下一篇

Criegee中间体RCHOO(R=H,CH3)与NO2反应机理及大气中HNO3的形成

周丽婷, 雷小洋, 王渭娜, 陈东平, 刘峰毅, 王文亮   

  1. 陕西省大分子科学重点实验室, 陕西师范大学化学化工学院, 西安 710119
  • 收稿日期:2017-11-10 修回日期:2018-04-20 出版日期:2018-05-10 发布日期:2018-04-20
  • 通讯作者: 王文亮,男,教授,博士生导师,主要从事理论与计算化学研究.E-mail:wlwang@snnu.edu.cn E-mail:wlwang@snnu.edu.cn
  • 基金资助:
    国家自然科学基金(批准号:21473108,21473107)和陕西省重点科技创新团队基金(批准号:2013KCT-17)资助.

Reaction Mechanism of Criegee Intermediate RCHOO(R=H, CH3) with Nitrogen Dioxide and Formation of HNO3 in the Atmosphere

ZHOU Liting, LEI Xiaoyang, WANG Weina, CHEN Dongping, LIU Fengyi, WANG Wenliang   

  1. Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710119, China
  • Received:2017-11-10 Revised:2018-04-20 Online:2018-05-10 Published:2018-04-20
  • Supported by:
    Supported by the National Natural Science Foundation of China(Nos.21473108, 21473107) and the Project of Innovative Team of Key Science and Technology of Shaanxi Province, China(No.2013KCT-17).

摘要: 采用CCSD(T)/aug-cc-pVTZ//M06-2X/cc-pVDZ方法研究了RCHOO(R=H,CH3)+NO2反应的微观机理,并讨论了甲基取代对反应活性的影响.结果表明,该反应存在加成-分解、氧化-氢转移和直接抽氢3类反应机理,其中氧化-氢转移反应的主要产物为RCO+HNO3,表观活化能仅为40.51 kJ/mol,且释放出235.04 kJ/mol的能量,是反应的优势通道;而生成RCHO+NO3自由基的加成-分解通道较难进行.甲基取代使α-C电正性增大,端氧负性增加,这有利于加成-分解和氧化-氢转移反应的进行,但syn-CH3CHOO中显著的位阻因素反而使加成-分解反应活性有所降低.

关键词: Criegee中间体, 二氧化氮, 反应机理, 反应活性

Abstract: The mechanism of RCHOO(R=H, CH3)+NO2 reaction was studied at CCSD(T)/aug-cc-pVTZ//M06-2X/cc-pVDZ level. The influence of the methyl substitution on the reactivity was discussed. The results show that the reaction could take place through three channels addition-decomposition, oxidative H-transfer and hydrogen abstraction. Therein, the oxidative H-transfer reaction, which mainly produces the RCO+HNO3, is the favorable pathway. The apparent activation energy and release energy of the oxidative H-transfer reaction are 40.51 and 235.04 kJ/mol, respectively. Moreover, the methyl substituent will lead to the increase of the electropositivity on α-C and decrease of the electronegativity on terminal O, which is advantageous to proceed the addition-decomposition and oxidation-hydrogen transfer reaction. However, the reactivity of the addition-decomposition reaction reduced because of the prominent steric effect in syn-CH3CHOO.

Key words: Criegee intermediate, Nitrogen dioxide, Reaction mechanism, Reaction activity

中图分类号: 

TrendMD: