Dielectric and thermodynamic investigation of heterocyclic compound Indole-3-Carbinol (I3C) using time domain reflectometry

Abstract

The present work aims at the study of dielectric relaxation spectroscopy, which involves the measurement of dielectric loss and dielectric permittivity of Indole-3-carbinol in (Dimethyl Sulfoxide) DMSO over the frequency range of 10 MHz to 50 GHz. Two relaxation modes were observed for the studied system. Low-frequency relaxation mode is observed at the frequency of about 80–100 MHz, which is attributed to Indole-3 Carbinol (I3C) molecules, and high-frequency relaxation is observed at about 6–7 GHz, which is due to DMSO molecules. The structural properties of I3C have been studied through dielectric parameters such as dielectric constant (εi), relaxation time (τi), distribution parameters, dipole moment, Kirkwood correlation factor (g), and number of DMSO molecules irrotationally bound to I3C molecules (Zib), and the results have been expressed in terms of molecular interaction between solute–solute and solute solvent (I3C and DMSO) molecules. The results obtained using dielectric spectroscopy are corroborated by the thermodynamic parameters.