Octanol-water partition coefficients of substituted phenols and their correlation with molecular descriptors

Abstract

Quantum mechanical molecular descriptors and physical properties have been used to estimate log K ow values for a range of substituted phenols using multilinear regression. The quantum mechanical molecular descriptors were derived from a commercially available software package. Two models have been proposed. The first model involves molecular mass and E HOMO as independent variables whereas the second model combines the following molecular descriptors: molecular mass, melting point, charge on oxygen atom, E HOMO , E LUMO , molecular volume, total surface area, refractivity, and polarizability. The equations were derived using a set of 14 reference phenolic compounds with their log k ow values being the average of several experimental values reported in the literature. The predictive power of the derived model equations was compared to a set of 18 test compounds, whose log K ow values have been estimated by an isocratic liquid chromatography (LC) procedure, log K ow values of the test compounds estimated on the basis of the two equations showed good correlation with LC estimated log K ow values.