title: Mechanism and kinetic properties for the OH-initiated atmospheric oxidation degradation of 9,10-Dichlorophenanthrene.
abstract: Chlorinated polycyclic aromatic hydrocarbons (ClPAHs) have become a serious environmental concern due to their widespread occurrence and dioxin-like toxicities. In this work, the mechanism of the OH-initiated atmospheric oxidation degradation of 9,10-dichlorophenanthrene (9,10-Cl₂Phe) was investigated by using high-accuracy quantum chemistry calculations. The rate constants of the crucial elementary reactions were determined by the Rice-Ramsperger-Kassel-Marcus (RRKM) theory. The theoretical results were compared with the available experimental data. The main oxidation products are a group of ring-retaining and ring-opening compounds including chlorophenanthrols, 9,10-dichlorophenanthrene-3,4-dione, dialdehydes, chlorophenanthrenequinones, nitro-9,10-Cl₂Phe and epoxides et al. The overall rate constant of the OH addition reaction is 2.35 × 10(-12)cm(3) molecule(-1)s(-1) at 298 K and 1 atm. The atmospheric lifetime of 9,10-Cl₂Phe determined by OH radicals is about 5.05 days. This study provides a comprehensive investigation of the OH-initiated oxidation degradation of 9,10-Cl₂Phe and should contribute to clarifying its atmospheric fate.
authors.affiliation: Environment Research Institute, Shandong University, Jinan 250100, P. R. China.
authors.forename: Juan
authors.initials: J
authors.lastname: Dang
authors.affiliation: Environment Research Institute, Shandong University, Jinan 250100, P. R. China.
authors.forename: Xiangli
authors.initials: X
authors.lastname: Shi
authors.affiliation: Environment Research Institute, Shandong University, Jinan 250100, P. R. China. Electronic address: zqz@sdu.edu.cn.
authors.forename: Qingzhu
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Environment Research Institute, Shandong University, Jinan 250100, P. R. China.
authors.forename: Jingtian
authors.initials: J
authors.lastname: Hu
authors.affiliation: Environment Research Institute, Shandong University, Jinan 250100, P. R. China.
authors.forename: Wenxing
authors.initials: W
authors.lastname: Wang
mesh_terms: D000393:Air Pollutants / Q000737:chemistry*; D001272:Atmosphere / Q000737:chemistry*; D017665:Hydroxyl Radical / Q000737:chemistry*; D007700:Kinetics; D008956:Models, Chemical; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry*
chemical_list: D000393:Air Pollutants; D011084:Polycyclic Aromatic Hydrocarbons; D017665:Hydroxyl Radical
keywords: 9,10-Dichlorophenanthrene; Degradation products; OH radicals; Oxidation mechanism; Rate constants