Molecular Polarizability. 1. Relationship to Water Solubility of Alkanes and Alcohols

The polarizability effect index (PEI) of groups and the molecular polarizability effect index (MPEI) are proposed on the basis of the principle that molecules are polarized by electric fields. Furthermore, by taking the sum of bond lengths (SBL) in a molecule and the difference in molecular polarizability effect index values (ΔMPEI) between branching chain and normal chain isomers as parameters, we studied the correlations of cavity surface area (CSA), water solubility (−log S), and partition coefficients in n-octanol/water (log P) with the SBL and ΔMPEI parameters for the alkanes and alcohols and got excellent linear correlations.