Polarizabilities of solvents from the chemical composition.

From the experimental polarizability values, alpha, of a large set of solvents containing 426 compounds with very different chemical characteristics, an additive model for the estimation of the polarizability is proposed. The derived average atomic polarizability of 10 elements, C, H, O, N, S, P, F, Cl, Br, and I, allows the calculation of the molecular polarizability of solvents from their chemical composition alone, without any other structural consideration. The average errors are 2.31% and 1.93% for the working set of 340 solvents and the prediction set of 86 solvents, respectively. Semiempirical quantum methods, such as, AM1, PM3, and MNDO, gave errors of about 35%. The density functional theory (DFT) calculations give better results than the semiempirical ones but poorer results than those obtained by the additive approach.