Microwave absorption and relaxation processes for some substituted benzotrifluorides in benzene solutions at different temperatures

Abstract

Measurements of static permittivity at 300 kHZ, refractive index (for the sodium D-line) and complex permittivity at 9.945 GHz have been made for five substituted benzotrifluorides, viz. o-aminobenzo-trifluoride (I), m-aminobenzotrifluoride (II), o-nitrobenzotrifluoride (III), m-nitrobenzotrifluoride (IV) and o-chlorobenzotrifluoride (V), in dilute solutions of benzene over a temperature range 25–55 °C. The relaxation time and distribution parameter have been evaluated from the measured dielectric data. The thermodynamic parameters and the frequency factors A′ and B′ are determined from the Eyring rate equations. The effects of molecular size and molecular and intramolecular motions on the relaxation time and energy parameters have been observed. Kalman's equation satisfactorily explains the relation between the dielectric relaxation time and the viscosity.