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 ( ), 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 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.