Thermodynamic and physical properties of binary mixtures involving sulfolane. Excess volumes and dielectric constants of benzonitrile-sulfolane and acetonitrile-sulfolane systems

Excess volumes and dielectric constants were measured for sulfolane + acetonitrile and sulfolane + benzonitrile mixtures over the entire composition range, 0 <= x <= 1, at several temperatures, ranging between 283.13 and 333.16 K. The observed low deviations from ideality are indicative of only moderate interactions of all kinds; nevertheless the experimental data supply evidence for the supposition that interactions between unlike molecules predominate in acetonitrile-sulfolane mixtures, whereas these interactions are relatively weak if compared with the average of the energies of interaction between benzonitrile pairs of molecules, in benzonitrile-sulfolane mixtures. © 1980 American Chemical Society.