Criegee中间体RCHOO(R=H,CH_3)与NO_2反应机理及大气中HNO_3的形成  

Reaction Mechanism of Criegee Intermediate RCHOO(R=H,CH_3) with Nitrogen Dioxide and Formation of HNO_3 in the Atmosphere

作　　者：周丽婷[1] 雷小洋 王渭娜[1] 陈东平 刘峰毅[1] 王文亮[1] ZHOU Liting;LEI Xiaoyang;WANG Weina;CHEN Dongping;LIU Fengyi;WANG Wenliang(Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi＇an 710119, China)

机构地区：[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

出　　处：《高等学校化学学报》2018年第5期956-963,共8页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:21473108;21473107);陕西省重点科技创新团队基金(批准号:2013KCT-17)资助~~

摘　　要：采用CCSD(T)/aug-cc-p VTZ//M06-2X/cc-p VDZ方法研究了RCHOO(R=H,CH_3)+NO_2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+HNO_3,表观活化能仅为40.51 k J/mol,且释放出235.04 k J/mol的能量,是反应的优势通道;而生成RCHO+NO_3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-CH_3CHOO中显著的位阻因素反而使加成-分解反应活性有所降低.The mechanism of RCHOO（ R = H,CH3） ＋NO2 reaction was studied at CCSD（ T）/aug-cc-p VTZ//M06-2 X/cc-p VDZ 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 k J/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 additiondecomposition reaction reduced because of the prominent steric effect in syn-CH3 CHOO.

关 键 词：Criegee中间体 二氧化氮 反应机理 反应活性 

分 类 号：O643.1[理学—物理化学]