Theoretical investigation on reaction mechanism and kinetics of m-xylene bicyclic peroxy radical with HO_(2)  

间二甲苯双环过氧自由基与HO_(2)反应机理和动力学理论研究

作　　者：Zhenli Yang Xiaofeng Tang Dongdong Shu Yinfeng Yang Xiaoxiao Lin Weijun Zhang 杨振丽;唐小锋;束冬冬;杨银凤;林晓晓;张为俊(安徽中医药大学医药信息工程学院,合肥230012;中国科学院合肥物质科学研究院安徽光学精密机械研究所,合肥230031;中国科学院等离子体物理研究所,合肥230031)

机构地区：[1]School of Medical Informatics Engineering,Anhui University of Chinese Medicine,Hefei 230012,China [2]Anhui Institute of Optics and Fine Mechanics,Hefei Institutes of Physical Science,Chinese Academy of Sciences,Hefei 230031,China [3]Institute of Plasma Physics,Chinese Academy of Sciences,Hefei 230031,China

出　　处：《Chinese Journal of Chemical Physics》2024年第6期831-839,I0014-I0026,I0043,共23页化学物理学报(英文)

基　　金：the Anhui University of Traditional Chinese Medicine High Level Talent Support Program Project(No.2021rcybO1);the National Natural Science Foundation of China(No.42075113,No.91544228);Scientific Research Program of Higher Education Institutions in Anhui Province(2023AH050836).

摘　　要：M-xylene bicyclic peroxy radical(M-BPR)is an important atmospheric intermediate formed by the oxidation of m-xylene,which plays an important role in the new particle formation and growth of secondary organic aerosol.In this work,the reaction mechanism,thermodynamic analysis,and kinetics of the reaction between M-BPR and HO_(2)were investigated at the CCSD(T)/cc-pVDZ//B3LYP/6-311G(d,p)level of theory coupled with transition state theory.The calculated results indicate that the title reaction can occur on both singlet and triplet potential energy surfaces,and the formation of hydroperoxides and 3O_(2)via triplet state is the main reaction channel,while the other four singlet product channels are negligible due to the higher barrier heights.Additionally,the reaction rate constants are estimated by using the transition state theory over the temperature range of 258 K to 378 K,and reaction rate constants arc found to be negatively correlated with temperature.At 298 K,the total rate constant for the title reaction is 1.86×10^(-11)cm^(3)·molecule^(-1)·s^(-1).The calculated rate constants over the studied temperature range were used to fit the data and the three-parameter Arrhenius ex-studied is obtainted to be k(T)=4.22×10^(-15)·(T/300)^(1.44)·exp(2505/T).间二甲苯双环过氧自由基是间二甲苯大气氧化过程中形成的重要中间体,在新粒子生成和二次有机气溶胶生长中起着重要作用.本文采用CCSD(T)/cc-pVDZ//B3LYP/6-311G(d,p)理论方法结合过渡态理论研究了间二甲苯双环过氧自由基和HO_(2)之间的反应机理、热力学和反应动力学.计算结果表明,该反应可以在单重态和三重态势能面上发生.其中,通过三重态势能面形成氢过氧化物和^(3)O_(2)是主要的反应通道,而其他四个单重态产物通道由于较高的反应能垒可忽略不计.另外,在258至378 K的温度区间内,利用过渡态理论反应速率常数进行估算,发现该反应速率常数与温度呈负相关关系.在298 K,反应的总速率常数为1.86×10^(-11)cm^(3)·molecule^(-1)·s^(-1).对一定温度范围内计算得出的速率常数进行数据拟合,得到阿伦尼乌斯公式为k(T)=4.22×10^(-15)·(T/300)^(1.44)·exp(2505/T).

关 键 词：M-XYLENE HO_(2)radical Bicyclic peroxy radical Reaction mechanism Transition statetheory 

分 类 号：O643.1[理学—物理化学]