CF_3CH=CH_2与大气Cl原子反应机理研究  

Theoretical Study on the Reaction Mechanisms between CF_3CH = CH_2 and Cl Atoms in Gas

作　　者：刘艳 LIU Yan(School of Chemistry and Materials,Weinan Normal University,Weinan 714099,China;School of Chemiswy and Chemical Engineering,Shaanxi Normal University,Xi＇an 710062,China)

机构地区：[1]渭南师范学院化学与材料学院,陕西渭南714099 [2]陕西师范大学化学化工学院,西安710062

出　　处：《渭南师范学院学报》2018年第20期22-27,共6页Journal of Weinan Normal University

基　　金：国家自然科学基金项目:全氟类强温室气体生成及降解机理的理论研究(21503150);陕西省自然科学基金项目:新温室气体SF5CF3大气环境下催化降解反应机理研究(2018JM2051);陕西省军民融合研究基金项目:乙苯CO2催化制备苯乙烯反应机理研究(18JMR34)

摘　　要：采用密度泛函B3PW91/6-311++g(d,p)方法对CF_3CH=CH_2与Cl原子的反应机理进行了理论研究,对所有反应物、过渡态以及产物的几何构型进行了全参数优化,通过振动频率分析和内禀反应坐标(IRC)分析方法证实了过渡态的真实性,用传统过渡态理论计算了最佳反应通道的速率常数。结果表明:CF_3CH=CH_2与Cl原子有6条可能的反应通道,其中最佳反应通道为Cl原子提取CF_3CH=CH_2分子中2个不同位上的H原子,分别生成主要产物P1(CF_3CH=CH+HCl)和P2(CF3C=CH_2+HCl);通道1和2的能垒高度分别为35.8 kJ/mol和32.1 k J/mol,为竞争反应通道。速率常数计算表明,在200～2 000 K温度范围内,高温有利于反应的发生,且温度越高,竞争反应越激烈。A theoretical study on the reaction mechanism of CF3CH = CH2 and Cl atoms was studied by density function B3PW91/6-311＋＋g （d, p） theory. The geometric configuration of all reactants, intemlediates, transition states and products was optimized by the full parameter. The authenticity of the transition state was confirmed by the vibration frequency analysis and the intrinsic reaction coordinate （IRC） analysis. The reaction rate constant of the best reaction channel was calculated by the traditional transition state theory. Six possible reaction pathways in the title reaction are found. The CI atom could abstract the H atoms in the site of end and internal in CF3 CH = CH： molecule. The main products are P1 （CF3 C H = CH＋HCI） and P2 （CF3 C = CH： ＋HCI） via TS1 and TS2 with small energy barriers of 35.8 and 32.1 kJ/mol, respectively. The rate constants for the favorable pathways would increase with the temperature in the range of 200- 200 0 K.

关 键 词：CF3CH=CH2 CL原子 反应机理 密度泛函理论 

分 类 号：O643.12[理学—物理化学]