title: Theoretical investigation on the mechanisms and kinetics of OH-initiated photooxidation of dimethyl phthalate (DMP) in atmosphere.
abstract: The atmospheric OH-initiated degradation mechanisms of dimethy phthalate (DMP) are analyzed at the MPWB1K/6-311++G(3df,2p)//MPWB1K/6-31+G(d,p) level of theory. The principal products detected experimentally are confirmed by this study while several major intermediates are reported for the first time. Additionally, the pathway scheme of hydroxylation reaction of DMP is proposed. The results about initial steps indicate that hydroxyl radical is most likely to be added to the ortho-carbon atom among additional reactions, while H atoms in methyl group are the most favorable to be abstracted by the OH radical. The rate constants of the elementary reactions over the temperature of 200-400 K were deduced using RRKM theory. The overall rate constant of the title reaction is 1.18×10(-12) cm(3) molecule(-1) s(-1) at 298 K and 760 Torr while H abstraction reactions predominate. According to the rate constants given at different temperatures, the Arrhenius equation is fitted. The atmospheric half life of DMP with respect to OH is estimated to be 6.8 days.
authors.affiliation: Environmental Research Institute, Shandong University, Jinan 250100, PR China.
authors.forename: Dandan
authors.initials: D
authors.lastname: Han
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Haijie
authors.initials: H
authors.lastname: Cao
authors.forename: Maoxia
authors.initials: M
authors.lastname: He
authors.forename: Jingtian
authors.initials: J
authors.lastname: Hu
authors.forename: Side
authors.initials: S
authors.lastname: Yao
mesh_terms: D000393:Air Pollutants / Q000032:analysis* / Q000737:chemistry; D001272:Atmosphere / Q000737:chemistry*; D017665:Hydroxyl Radical / Q000737:chemistry; D007700:Kinetics; D008956:Models, Chemical; D010084:Oxidation-Reduction; D055668:Photochemical Processes; D010795:Phthalic Acids / Q000032:analysis* / Q000737:chemistry; D013696:Temperature
chemical_list: D000393:Air Pollutants; D010795:Phthalic Acids; C024629:dimethyl phthalate; D017665:Hydroxyl Radical
keywords: Dimethy phthalate (DMP); Hydroxylation reaction; Mechanism and kinetics; Rate constants