Solubility properties in polymers and biological media 5: an analysis of the physicochemical properties which influence octanol-water partition coefficients of aliphatic and aromatic solutes.

Octanol-water partition coefficients of 102 aliphatic, polychloro aliphatic, and aromatic non-hydrogen-bond donor and hydrogen-bond donor solutes are well correlated (r = 0.989, SD = 0.175) by the equation: log Kow = 0.20 + 2.74 V/100 - 0.92 pi - 3.49 beta, where V is the molar volume (taken as the molecular weight divided by the liquid density) and pi and beta are the solvatochromic parameters that measure solute dipolarity/polarizability and hydrogen-bond acceptor basicity. A set of "ground rules" (modifications of the input parameters) are described which allow the inclusion of both aliphatic and aromatic solutes in the same correlation equation. Monomer beta values (betam) are used for alcohol solutes.