Atmospheric oxidation mechanisms of polychlorinated dibenzo-p-dioxins are different from those of benzene and dibenzofuran: a theoretical prediction.
The reaction mechanisms of dibenzo-p-dioxin (DD) and 2,3,7,8-TCDD with OH radical have been studied using density functional theory calculations. Under the atmospheric conditions, ca 42% of DD+OH reaction proceeds as formation of DD-OH-β adduct, which will react with O(2) slowly; while the rest will proceed as formation of DD-OH-γ adduct, which will decompose to the substituted phenoxy radical P1 by the fused-ring C-O bond cleavage. For 2,3,7,8-TCDD+OH, the reaction will predominantly form the substituted phenoxy radical P2. The reaction mechanisms are drastically different from the peroxy mechanism for the atmospheric oxidations of benzene and dibenzofuran.
School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640, China. wanglm@scut.edu.cn
Liming
L
Wang
Aili
A
Tang
D000393:Air Pollutants / Q000737:chemistry*; D001272:Atmosphere / Q000737:chemistry*; D001554:Benzene / Q000737:chemistry*; D001572:Benzofurans / Q000737:chemistry*; D017665:Hydroxyl Radical / Q000737:chemistry; D007700:Kinetics; D008962:Models, Theoretical; D010084:Oxidation-Reduction; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives* / Q000737:chemistry
D000393:Air Pollutants; D001572:Benzofurans; D000072317:Polychlorinated Dibenzodioxins; D017665:Hydroxyl Radical; C023614:dibenzofuran; D001554:Benzene