QSPR models for polychlorinated biphenyls: n-Octanol/water partition coefficient

The success of any QSPR model depends on the selection of proper descriptors. Exploring the usefulness of descriptors, especially, conceptual DFT based global electrophilicity index ( ω) along with the energy of lowest unoccupied molecular orbital ( E LUMO) and the number of chlorine substituents ( N Cl) in analyzing the lipophilic behaviour (log K ow) for 133 PCBs congeners is assessed. Existence of high correlation indicates the significance of the developed model in property prediction. The logarithmic n-octanol/water partition coefficient (log K ow) is an important property for pharmacology, toxicology and medicinal chemistry. Quantitative structure–property relationship (QSPR) model for the lipophilic behaviour (log K ow) of the data set containing 133 polychlorinated biphenyl (PCB) congeners is analyzed using the conceptual density functional theory based global reactivity parameter such as electrophilicity index ( ω) along with energy of lowest unoccupied molecular orbital ( E LUMO) and number of chlorine substituents ( N Cl) as descriptors. A reasonably good coefficient of determination ( r 2 = 0.914) and the internal predictive ability ( r cv 2 = 0.909 ) values are obtained indicating the significance of the considered descriptors in the property analysis of PCBs. Further, the developed method has widespread applicability from chemical reactivity to toxicity analysis and in studies related to various physicochemical properties in the series of dioxins and other polyaromatic hydrocarbons.