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_wand 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.