title: Atmospheric oxidation mechanism of chlorobenzene.
abstract: The atmospheric oxidation mechanism of chlorobenzene (CB) initiated by the OH radicals is investigated at M06-2X/6-311++G(2df, 2p) and ROCBS-QB3 levels. The oxidation is initiated by OH addition to the ortho (∼50%), para (∼33%) and meta (∼17%) positions, forming CB-OH adducts as R2, R3, and R4; while the ipso-addition is negligible (∼0.2%). The reactions of the CB-OH adducts with the atmospheric oxygen are further investigated in detail by coupling the unimolecular reaction rate theory calculations with master-equation (RRKM-ME). The CB-OH adducts react with O2 either by irreversible H-abstraction to form chlorophenol and HO2 or by reversible additions to form CB-OH-O2 radicals, which subsequently cyclize to bicyclic radicals. RRKM-ME calculations show that the addition reactions of CB-OH and O2 at the atmospheric pressure are close to but not yet reach their high-pressure-limits. The RRKM-ME simulations predict the yields of 93%, 38%, and 74% for ortho-, meta- and para-chlorophenols from the reactions of O2 with R2, R3 and R4, being lower than their high-pressure-limit yields of 95%, 48%, an 80%, respectively. Overall, the yield of chlorophenols is determined as 72% at the atmospheric pressure.
authors.affiliation: School of Chemistry & Chemical Engineering, South China University of Technology, Guangzhou 510640, China.
authors.forename: Runrun
authors.initials: R
authors.lastname: Wu
authors.affiliation: School of Chemistry & Chemical Engineering, South China University of Technology, Guangzhou 510640, China.
authors.forename: Sainan
authors.initials: S
authors.lastname: Wang
authors.affiliation: School of Chemistry & Chemical Engineering, South China University of Technology, Guangzhou 510640, China; Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, South China University of Technology, Guangzhou 510006, China. Electronic address: wanglm@scut.edu.cn.
authors.forename: Liming
authors.initials: L
authors.lastname: Wang
mesh_terms: D000393:Air Pollutants / Q000737:chemistry*; D001272:Atmosphere / Q000737:chemistry; D002722:Chlorobenzenes / Q000737:chemistry*; D017665:Hydroxyl Radical / Q000737:chemistry*; D007700:Kinetics; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D011312:Pressure
chemical_list: D000393:Air Pollutants; D002722:Chlorobenzenes; D017665:Hydroxyl Radical; C031294:chlorobenzene; D010100:Oxygen
keywords: Atmospheric oxidation mechanism; Chlorobenzene; Chlorophenols; OH radical