title: PBCDD/F formation from radical/radical cross-condensation of 2-Chlorophenoxy with 2-Bromophenoxy, 2,4-Dichlorophenoxy with 2,4-Dibromophenoxy, and 2,4,6-Trichlorophenoxy with 2,4,6-Tribromophenoxy.
abstract: Quantum chemical calculations were carried out to investigate the homogeneous gas-phase formation of mixed polybrominated/chlorinated dibenzo-p-dioxins/benzofurans (PBCDD/Fs) from the cross-condensation of 2-chlorophenoxy radical (2-CPR) with 2-bromophenoxy radical (2-BPR), 2,4-dichlorophenoxy radical (2,4-DCPR) with 2,4-dibromophenoxy radical (2,4-DBPR), and 2,4,6-trichlorophenoxy radical (2,4,6-TCPR) with 2,4,6-tribromophenoxy radical (2,4,6-TBPR). The geometrical parameters and vibrational frequencies were calculated at the MPWB1K/6-31+G(d,p) level, and single-point energy calculations were performed at the MPWB1K/6-311+G(3df,2p) level of theory. The rate constants of the crucial elementary reactions were evaluated by the canonical variational transition-state (CVT) theory with the small curvature tunneling (SCT) correction over a wide temperature range of 600-1200K. Studies show that the substitution pattern of halogenated phenols not only determines the substitution pattern of the resulting PBCDD/Fs, but also has a significant influence on the formation mechanism of PBCDD/Fs, especially on the coupling of the halogenated phenoxy radicals.
authors.affiliation: Environment Research Institute, Shandong University, Jinan 250100, PR China.
authors.forename: Xiangli
authors.initials: X
authors.lastname: Shi
authors.affiliation: Environment Research Institute, Shandong University, Jinan 250100, PR China; College of Resources and Environment, Linyi University, Linyi 276000, PR China.
authors.forename: Wanni
authors.initials: W
authors.lastname: Yu
authors.affiliation: Environment Research Institute, Shandong University, Jinan 250100, PR China.
authors.forename: Fei
authors.initials: F
authors.lastname: Xu
authors.affiliation: Environment Research Institute, Shandong University, Jinan 250100, PR 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, PR China.
authors.forename: Jingtian
authors.initials: J
authors.lastname: Hu
authors.affiliation: Environment Research Institute, Shandong University, Jinan 250100, PR China.
authors.forename: Wenxing
authors.initials: W
authors.lastname: Wang
mesh_terms: D001572:Benzofurans / Q000138:chemical synthesis*; D002733:Chlorophenols / Q000737:chemistry*; D003198:Computer Simulation; D010636:Phenols / Q000737:chemistry*; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives* / Q000138:chemical synthesis
chemical_list: D001572:Benzofurans; D002733:Chlorophenols; D010636:Phenols; D000072317:Polychlorinated Dibenzodioxins; C042329:phenoxy radical; C023614:dibenzofuran
keywords: 2,4,6-Tribromophenoxy radicals; 2,4,6-Trichlorophenoxy radicals; 2,4-Dibromophenoxy radicals; 2,4-Dichlorophenoxy radicals; 2-Bromophenoxy radicals; 2-Chlorophenoxy radicals