HQSAR and CoMFA approaches in predicting reactivity of halogenated compounds with hydroxyl radicals

Two quantitative structure–activity relationship (QSAR) methods: hologram QSAR (HQSAR) and comparative molecular field analysis (CoMFa) were evaluated for predicting half-lives of the hydroxyl radicals reaction with substituted aromatic compounds. The HQSAR approach, which is topological in nature, results in a mathematical model which was more stable and has a greater predictive ability than the model derived on the 3-D CoMFA approach. Interpretations of the colour coded results of both methods are in good agreement with the proposed mechanism of the hydroxyl radical oxidation of halogenated aromatic compounds in the atmosphere.