Double relaxation phenomena of monosubstituted anilines in benzene under high frequency electric field

The intercept and slope of a derived linear equation: (χoij - χij′)/χij′ = ω (τ1+τ2) χij″/χij′ - ω2τ1τ2 for different weight fractions wj's of monosubstituted anilines (j) in benzene(i) at 35°C under different electric field frequencies are used to yield the double relaxation times τ1 and τ2 of the flexible parts and the whole molecules. χij′ and χij″ are the real and imaginary parts of hf complex dielectric orientational susceptibility χij∗ and χoij is the low frequency dielectric susceptibility which is real. τj's obtained from the ratio of the individual slopes of variations of χij∥ and χij′ with wj's at wj→0 are compared with Murthy et al (Indian J Phys 63 B 1989 491) and Gopalakrishna (Trans Faradey. Soc. 53 1957 767). The theoretical weighted contributions c1 and c2 for τ1 and τ2 from Frohlichs' equations are compared with the experimental ones from the graphically fitted curves of χij′/χoij and χij″/χoij with wj's in the limit wj=0. The values of (χij′/χoij)wj→0 and (χij″/χoij)wj→0 are again employed to get symmetric and asymmetric distribution parameters γ and δ, the latter one is from the curve of 1/ϕ log Cosϕ against ϕ0, to yield the symmetric and characteristic relaxation times τs and τcs respectively, only to show that symmetric relaxation behaviour is obeyed by the molecules. The dipole moments μ1 and μ2 for the rotation of flexible parts and the whole molecules are measured from τ1 and τ2 and linear coefficient s's of the variations of χij′ and hf conductivity σij with wj's. The measured μ1 and μ2 are compared with the reported μ's and μtheo's of available bond angles and bond moments of the substituent polar groups of the parent molecules. The slight disagreement of measured μ's from μtheo's indicates the existence of inductive, mesomeric and electromeric effects suffered by the polar groups under hf electric field.