Improved prediction of octanol-water partition coefficients from liquid-solute water solubilities and molar volumes

A volume-fraction-based solvent-water partition model for dilute solutes, in which the partition coefficient shows a dependence on solute molar volume ((V) over bar), is adapted to predict the octanol-water partition coefficient (K-ow) from the liquid or supercooled-liquid solute water solubility (S-w) or vice versa. The established correlation is tested for a wide range of industrial compounds and pesticides (e.g., halogenated aliphatic hydrocarbons, alkylbenzenes, halogenated benzenes, ethers, esters, PAHs, PCBs, organochlorines, organophosphates, carbamates, and amides-ureas-triazines), which comprise a total of 215 test compounds spanning about 10 orders of magnitude in S-w and 8.5 orders of magnitude in K-ow. Except for phenols and alcohols, which require special considerations of the K-ow data, the correlation predicts the K-ow within 0.1 log units for most compounds, much independent of the compound type or the magnitude in K-ow. With reliable S-w and (V) over bar data for compounds of interest, the correlation provides an effective means for either predicting the unavailable log K-ow values or verifying the reliability of the reported log K-ow data.