Dielectric dispersion studies of mixtures of aniline and benzonitrile in benzene solutions

Dielectric behavior of aniline, benzonitrile and their binary mixtures of different concentrations were studied in benzene at 293, 303, 313 and 323 K. The complex permittivity (∈′, ∈″) at microwave frequencies 7.22, 9.1, 19.61 GHz, static permittivity ∈₀ at 455 KHz and high frequency limiting dielectric constant ∈_∞ = n_D² at optical frequency of these molecules and their binary mixtures were measured. The average relaxation time (τ₀), distribution parameter (α) and thermodynamical parameters were determined. The plot of relaxation time (τ₀) against concentration of benzonitrile in the mixtures is nonlinear indicating complex formation.