Dielectric behavior of indole in the GHz region using TDR

Abstract

The effect of microwave frequencies on the structural and dynamical properties of heterocyclic organic compound such as Indole in the surrounding of DMSO (Dimethyl sulphoxide) molecule has been studied over the temperature region 298.15 K to 273.15 K using Time Domain Reflectometry (TDR) in the frequency region of 10 MHz–50 GHz. Dielectric parameters including Static permittivity (ε′), Dielectric constant (ε0), Relaxation time (τ) Kirkwood correlation factor (g) and dipole moment (μ) which is well supported by thermodynamic parameters such as activation and molal/M Free energy (∆F), Entropy (∆S) and Enthalpy (∆H) have been calculated. The dielectric permittivity spectra and relaxation behavior of Indole in different concentrations with DMSO was analyzed using Debye model. Dielectric loss peak for all studied temperature observed to be shifted towards lower frequency side with increasing concentration. Also, it was observed that, Dielectric constant(ε0) increases for lower concentration and then starts decreasing towards higher concentrations. Dielectric constant was also affected by temperature as, the value decreases for higher temperature. Dielectric relaxation time (τ) show increasing behavior with concentration C. However, relaxation time seems to be decreasing as we increase the temperature towards room temperature.