Rate constants of hydroxyl radical oxidation of polychlorinated biphenyls in the gas phase: A single-descriptor based QSAR and DFT study

Zhihui Yang; Shuang Luo; Zongsu Wei; Tiantian Ye; Richard Spinney; Dong Chen; Ruiyang Xiao

doi:10.1016/j.envpol.2015.12.044

Rate constants of hydroxyl radical oxidation of polychlorinated biphenyls in the gas phase: A single-descriptor based QSAR and DFT study

Environ Pollut. 2016 Apr:211:157-64. doi: 10.1016/j.envpol.2015.12.044. Epub 2015 Dec 31.

Authors

Zhihui Yang¹, Shuang Luo¹, Zongsu Wei², Tiantian Ye¹, Richard Spinney³, Dong Chen⁴, Ruiyang Xiao⁵

Affiliations

¹ Institute of Environmental Engineering, School of Metallurgy and Environment, Central South University, Changsha, 410083, China; Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Changsha, 410083, China.
² Department of Civil, Environmental and Geodetic Engineering, The Ohio State University, Columbus, OH, 43210, USA.
³ Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, 43210, USA.
⁴ Indiana University-Purdue University Fort Wayne, Fort Wayne, Indiana, 46805, USA.
⁵ Institute of Environmental Engineering, School of Metallurgy and Environment, Central South University, Changsha, 410083, China; Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Changsha, 410083, China. Electronic address: xiao.53@csu.edu.cn.

PMID: 26748251
DOI: 10.1016/j.envpol.2015.12.044

Abstract

The second-order rate constants (k) of hydroxyl radical (·OH) with polychlorinated biphenyls (PCBs) in the gas phase are of scientific and regulatory importance for assessing their global distribution and fate in the atmosphere. Due to the limited number of measured k values, there is a need to model the k values for unknown PCBs congeners. In the present study, we developed a quantitative structure-activity relationship (QSAR) model with quantum chemical descriptors using a sequential approach, including correlation analysis, principal component analysis, multi-linear regression, validation, and estimation of applicability domain. The result indicates that the single descriptor, polarizability (α), plays an important role in determining the reactivity with a global standardized function of lnk = -0.054 × α ‒ 19.49 at 298 K. In order to validate the QSAR predicted k values and expand the current k value database for PCBs congeners, an independent method, density functional theory (DFT), was employed to calculate the kinetics and thermodynamics of the gas-phase ·OH oxidation of 2,4',5-trichlorobiphenyl (PCB31), 2,2',4,4'-tetrachlorobiphenyl (PCB47), 2,3,4,5,6-pentachlorobiphenyl (PCB116), 3,3',4,4',5,5'-hexachlorobiphenyl (PCB169), and 2,3,3',4,5,5',6-heptachlorobiphenyl (PCB192) at 298 K at B3LYP/6-311++G**//B3LYP/6-31 + G** level of theory. The QSAR predicted and DFT calculated k values for ·OH oxidation of these PCB congeners exhibit excellent agreement with the experimental k values, indicating the robustness and predictive power of the single-descriptor based QSAR model we developed.

Keywords: DFT; Hydroxyl radical; PCBs; Polarizability; Single–descriptor based QSAR.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Atmosphere / chemistry
Hydroxyl Radical*
Kinetics
Models, Chemical*
Oxidation-Reduction*
Polychlorinated Biphenyls / analysis
Polychlorinated Biphenyls / chemistry*
Quantitative Structure-Activity Relationship

Substances

2,4',5-trichlorobiphenyl
Hydroxyl Radical
2,3,4,5,3',4',5'-heptachlorobiphenyl
2,4,2',4'-tetrachlorobiphenyl
Polychlorinated Biphenyls
3,4,5,3',4',5'-hexachlorobiphenyl