Mechanism and rate constants for complete series reactions of 19 fluorophenols with atomic H  

作　　者：Rui Gao Xiaoyan Sun Wanni Yu Qingzhu Zhang Wenxing Wang 

机构地区：[1]Environment Research Institute, Shandong University

出　　处：《Journal of Environmental Sciences》2014年第1期154-159,共6页环境科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(No.21177077,21177076);the Independent Innovation Foundation of Shandong University(No.2012JC030)

摘　　要：Fluorine-containing halogenated fluorophenol may have effect as intermediate species involved in the formation of polyfluorinated dibenzo-p-dioxin/dibenzofurans （PFDDs/Fs）. The mechanism for the atomic H initiated reactions with complete series of nineteen fluorophenol congeners was studies using the density functional theory. At the MPWB1K,/6-31＋G（d,p） level, the geometries and frequencies of reactants, transition states, and products were obtained, and the accurate energetic values were acquired at the MPWB 1K/6-311 ＋G（3df,2p） level. The rate constants were evaluated by the canonical variational transition-state theory with the small curvature tunneling contribution over a wide temperature range of 600-1000 K. The study shows that the intramolecular hydrogen-bond in the ortho-substituted FPs as well as the inductive effect of the electron-withdrawing fluorine and steric repulsion of multiple substitutions may ultimately be responsible for the relative strength of the O-H bonds in FPs. The results can be used for further studies on PFDD/Fs formation mechanism.Fluorine-containing halogenated fluorophenol may have effect as intermediate species involved in the formation of polyfluorinated dibenzo-p-dioxin/dibenzofurans （PFDDs/Fs）. The mechanism for the atomic H initiated reactions with complete series of nineteen fluorophenol congeners was studies using the density functional theory. At the MPWB1K,/6-31＋G（d,p） level, the geometries and frequencies of reactants, transition states, and products were obtained, and the accurate energetic values were acquired at the MPWB 1K/6-311 ＋G（3df,2p） level. The rate constants were evaluated by the canonical variational transition-state theory with the small curvature tunneling contribution over a wide temperature range of 600-1000 K. The study shows that the intramolecular hydrogen-bond in the ortho-substituted FPs as well as the inductive effect of the electron-withdrawing fluorine and steric repulsion of multiple substitutions may ultimately be responsible for the relative strength of the O-H bonds in FPs. The results can be used for further studies on PFDD/Fs formation mechanism.

关 键 词：fluorophenols fluorophenoxy radicals atomic H hydrogen bond reaction mechanism rate constants 

分 类 号：X705[环境科学与工程—环境工程]