标题：Kinetics and mechanism for chlorine-initiated atmospheric oxidation of ethyl formate
作者：Zhao, Yan; Sun, Xiaomin; Wang, Wenxing; Xu, Laixiang
作者机构：[Zhao, Yan] Shandong Univ, Sch Chem & Chem Engn, Jinan 250100, Peoples R China.; [Zhao, Yan] Qufu Normal Univ, Sch Life Sci, Qufu 273165, Peoples R 更多
通讯作者地址：[Zhao, Y]Shandong Univ, Sch Chem & Chem Engn, Jinan 250100, Peoples R China.
来源：CANADIAN JOURNAL OF CHEMISTRY
关键词：ethyl formate; chlorine atom; reaction mechanism; kinetic parameters
摘要：The chlorine-initiated reaction mechanism of ethyl formate in the atmosphere was investigated using the density functional theory method. The geometry parameters and frequencies of all of the stationary points were calculated at the B3LYP/6-31G(d, p) level. The single-point energy calculations were carried out at different levels, including MP2/6-31G(d), MP2/6-311++G(d, p), and CCSD(T)/6-31G(d). A detailed oxidation mechanism is provided and discussed. Present results show that alpha-ester rearrangement reaction and the O-2 direct abstraction from IM6 (HC(O)OCH(O)CH3) are the more favorable pathway and are competitive. The 1,4-H shift isomerization of IM6 proved to be feasible under general atmospheric conditions. The decomposition of IM18 (CH3CH2OC(O)O) is favorable both thermodynamically and kinetically. Canonical variational transition theory with small-curvature tunneling correction was employed to predict the rate constants. The overall rate constant of ethyl formate at 298 K is 8.63 x 10(-12) cm(3) molecule(-1) s(-1). The Arrhenius equations of rate constants at the temperature range of 200-380 K were fitted.