PREDICTION OF REACTION RATE CONSTANTS OF HYDROXYL RADICAL WITH ORGANIC COMPOUNDS

Journal of The Chilean Chemical Society

CHEN, ZHEN¹  YU, XINLIANG¹  ZHANG, SHIHUA¹  HUANG, XIANWEI¹ 

[1] Hunan Institute of Engineering, Xiangtan, China

关键词: alkenes;    aromatics;    density functional theory;    quantum chemical;    structure-;    activity relationships;    rate constant.;   

DOI  :  10.4067/S0717-97072014000100003

学科分类：化学（综合）

来源: Sociedad Chilena de Quimica

【 摘 要 】

In this work we have performeda QSAR study of atmospheric reactions with hydroxyl radical, at the B3LYP levelof theory with 6-31G(d) basis set. Molecular descriptors selected by applyingmultiple linear stepwise regression (MLR) analysis were used to predict thereaction rate constants (-logkOH) of OH radicals with organiccompounds in the atmosphere, including 98 alkenes and 80 aromatic compounds.For setting our reactions, we have calculated 98 alkenes and 80 aromatic compounds.A four-descriptor MLR model (rms = 0.102 and R2= 0.938) for98 alkenes was developed based on the number of R=CHX functional group counts,EHOMO parameter, and Fukui indices of the double-bonded C atoms.We found vinyl chemicals with conjugated double bonds and electron-donorsubstituents are the most reactive systems; while alkenes with multiple halogensubstitutions are the least reactive molecules. Additionally, a three-descriptorMLR model (rms = 0.282 and R2= 0.910) was built to predictOH radical rate constants for 80 aromatic compounds, which was dominated bythe EHOMO parameter, a topological descriptor for steric hindrance,and the most positive net atomic charge on hydrogen atoms. Aromatics with electron-donorand electron-acceptor groups, respectively, possess high and low degradationrates. The halogen aromatics are less reactive, especially for aromatics withmultiple halogen substitutions. In comparison to existing models, the two modelsobtained in this paper show better statistical quality.

【 授权许可】

Unknown