Polarity and acidity of solvents. Part 3. Polarity of non-aromatic polychloro-substituted solvents

Abstract

The empirical solvent polarity parameters E_T(30), (π*), and (G) have been measured for thirty-four non-aromatic polychloro-substituted solvents. The E_T(30) values of these polychloro-substituted solvents, determined by means of the betaine dyes (1a) and (1b), are practically insensitive to the solvent polarizability, as previously found for the corresponding E_T(30) values of hydrocarbon and aromatic solvents. The difference between the empirical solvent parameters E_T(30), (π*), (G), and * for these three groups of solvents (i.e. alkanes, polychloroalkanes, and aromatics) stems above all from their different susceptibility to solvent polarizability. For those polychloroalkanes capable of solute ⋯ H–C hydrogen bonding, the empirical solvent parameters depend also on their different sensitivity to the C–H acidity of the solvent.