高等学校化学学报2013，Vol.34Issue(3)：641-649,9.DOI:10.7503/cjcu20120589
CF3CH2CF2CH3(HFC-365mfc)与Cl原子反应的微观机理及动力学性质
Mechanism and Kinetics for Reaction of CF3CH2CF2CH3(HFC-365mfc) with Cl Atom
摘要
Abstract
The mechanism of the CF3CH2CF2CH3+C1 reaction was investigated by the M06-2X method combining with the 6-31+G(d,p) basis set[ M06-2X/6-31+G(d,p) ]. There were two distinguishable stable con-formers (RC1 and RC2) for the reactant CF3CH2CF2CH3, and eight H-abstraction channels as well as two substitution channels were located associated with them. The rate constants for each of the H-abstraction channels were evaluated by the improved canonical variational transition state theory (ICVT) with the small-curvature tunneling(SCT) approximation at the M06-2X/6-31+G(d,p) level. The overall rate constant(kT) was obtained by considering the weight factor of each conformer from the Boltzmann distribution function, and the calculated values agree well with the available experimental values. Moreover, the contribution of the two con-formers to the whole reaction as well as the site selectivity for each of the conformers were discussed. A three-parameter rate constant-temperature expression for the total reaction within 200-1000 K was fitted to kT = 1. 88×l0-22T3.76exp( -1780. 69/T). In addition, because of the lack of available experimental data for the reactant as well as the corresponding product radicals involved in the reactions, their enthalpies of the formation (△Hf,298K) were predicted via isodesmic reaction at the M06-2X/6-31+G(d,p) level.关键词
密度泛函理论/直接动力学/速率常数/改进的正则变分过渡态理论/CF3CH2CF2CH3Key words
Density functional theory/ Direct dynamics/ Rate constant/ Improved canonical variational transition state theory/ CF3CH2CF2CH3分类
化学化工引用本文复制引用
金铜音,王钦,刘靖尧..CF3CH2CF2CH3(HFC-365mfc)与Cl原子反应的微观机理及动力学性质[J].高等学校化学学报,2013,34(3):641-649,9.基金项目
国家自然科学基金(批准号:20973077,20303007)和教育部新世纪优秀人才支持计划资助. （批准号:20973077,20303007）
