Molecular polarizability as a single-parameter predictor of vapour pressures and octanol–air partitioning coefficients of non-polar compounds: a priori approach and results

We present a one-parameter quantitative structure–property relationship (QSPR) which relates the vapour pressures, PL, and octanol–air partition coefficients, KOA, of a series of chlorinated organic compounds to their molecular polarizabilities. Polarizabilities, dipole moments and quadrupole moments were calculated for the complete set of chlorobenzenes, the mono-, di-, and tri-substituted chloronaphthalenes, the mono-, di-, tri-, and tetra-substituted chlorobiphenyls, and the chloroalkanes with one, two and three carbons using Density Functional Theory methods at the B3LYP/6-311G(d, p) level. Only the molecular polarizability was found to be significantly correlated with logPL and logKOA. The regression coefficients for plots of experimental values of logPL and logKOA as a function of molecular polarizability are approximately 0.98, indicating that non-specific intermolecular forces are dominant in governing the gas–condensed phase transition in these molecules. The predictive ability of the single-parameter QSPR is suggested by near-identical values of the residual sum of squares and PRESS parameters. We suggest that the QSPRs derived here could be used more generally.