Polarity and hydrogen-bonding ability of some binary aqueous–organic mixtures

Abstract

The solvatochromic parameters π* for the polarity/polarizability, β for the hydrogen-bond accepting (electron-pair-donating) ability, and α for the hydrogen-bond-donating ability of binary aqueous tetrahydrofuran, N,N-dimethylformamide, pyridine, dimethyl sulphoxide, formamide and formic acid have been determined spectrophotometrically at 25 °C as functions of the composition of the mixtures. They were compared with the local composition of the environment of each kind of molecules in the mixtures, obtained from theoretical models. These parameters were also determined for several water-saturated alkanols and tri-n-butyl phosphate, that are of significance in liquid–liquid distribution studies of organic solutes.