Quantitative Structure-Activity Relationships Study on the Rate Constants of Polychlorinated Dibenzo-p-Dioxins with OH Radical.
The OH-initiated reaction rate constants (kOH) are of great importance to measure atmospheric behaviors of polychlorinated dibenzo-p-dioxins (PCDDs) in the environment. The rate constants of 75 PCDDs with the OH radical at 298.15 K have been calculated using high level molecular orbital theory, and the rate constants (kα, kβ, kγ and kOH) were further analyzed by the quantitative structure-activity relationships (QSAR) study. According to the QSAR models, the relations between rate constants and the numbers and positions of Cl atoms, the energy of the highest occupied molecular orbital (EHOMO), the energy of the lowest unoccupied molecular orbital (ELUMO), the difference ΔEHOMO-LUMO between EHOMO and ELUMO, and the dipole of oxidizing agents (D) were discussed. It was found that EHOMO is the main factor in the kOH. The number of Cl atoms is more effective than the number of relative position of these Cl atoms in the kOH. The kOH decreases with the increase of the substitute number of Cl atoms.
College of Chemical Engineering, Beijing Institute of Petrochemical Technology, Beijing 102617, China. qichuansong@bipt.edu.cn.
Chuansong
C
Qi
Environment Research Institute, Shandong University, Jinan 250100, China. sdzhangcx@163.com.|Department of Resources and Environment, Binzhou University, Binzhou 256600, China. sdzhangcx@163.com.
Chenxi
C
Zhang
Environment Research Institute, Shandong University, Jinan 250100, China. sxmwch@sdu.edu.cn.
Xiaomin
X
Sun
D017665:Hydroxyl Radical / Q000737:chemistry*; D008956:Models, Chemical; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives* / Q000737:chemistry; D021281:Quantitative Structure-Activity Relationship
D000072317:Polychlorinated Dibenzodioxins; D017665:Hydroxyl Radical
number and position of  Cl atom; polychlorinated dibenzo-p-dioxins; quantitative structure-activity relationships; rate constants