Dielectric relaxation in non-aqueous solutions. Part 3.—Solutions of tetra(n-butyl)ammonium bromide in 1,2-dichloroethane and pentan-3-one

Abstract

The frequency dependence of the complex permittivity of a series of solutions of tetra(n-butyl) ammonium bromide in 1,2-dichloroethane and pentan-3-one has been studied in the frequency range 0.4 to 3.0 GHz at four temperatures between 0 and 45°C. The dispersion of permittivity observed in the majority of cases cannot be adequately described by means of a single relaxation time. A non-zero distribution parameter must also be included, while the dispersion amplitude is not even an approximately linear function of electrolyte concentration. Possible loss mechanisms involving the rotational diffusion of ion-pairs and the translational diffusion of free ions have been considered in an attempt to interpret these observations.

The electrical conductivity and permittivity of representative solutions in 1,2-dichloroethane have been measured between 1 and 100 MHz in addition to the real and imaginary permittivities of the pure solvents at frequencies up to 3 GHz. Density data for solutions of the salt in 1,2-dichloroethane are included and from these data, the partial molar volume of the solute has been evaluated.