Dielectric relaxation in the mixtures of some nitriles

Dielectric constants and losses have been measured at wavelengths of 3 × 104, 10.0, 3.22, 1.96, and 1.25 cm at 30°C for pure acetonitrile, pure propionitrile, five mixtures of acetonitrile and benzonitrile and three mixtures of propionitrile and benzonitrile. A single relaxation time of 3.3 × 10–12 s has been obtained for pure acetonitrile, whereas the dielectric data of pure propionitrile indicate an unsymmetrical distribution of relaxation times in good agreement with the Davidson-Cole representation. The dielectric data of the binary mixtures of acetonitrile and benzonitrile have been analyzed in terms of two partly superimposed Deby e regions, whereas that of propionitrile and benzonitrile have been interpreted in terms of three partly overlapping Debye regions.