Molecular and group relaxation of a few solutes in liquid o-terphenyl

✍ Scribed by J. Crossley; S.P. Tay; M.S. Walker; S. Walker

• Publisher: Elsevier Science
• Year: 1981
• Weight: 425 KB
• Volume: 20
• Category: Article
• ISSN: 0378-4487
• DOI: 10.1016/0378-4487(81)80053-2

✦ Synopsis

Dielectric constant and loss data have been obtained at up to eight frequencies between1 and ;GGHz for five parasubstituted benzenes in o-terphenyl at a few temperatures above the melting point. The data have been analyzed for mean relaxation times, 'co, and some estimates have been made of the enthalpy of activation for the molecular process and in two cases for the intramolecular process. In the case of p-methylanisole in o-terphenyl the work indicates a contribution from both the molecular ('II) and the intramolecular (TZ) relaxation processes whereas microwave studies on this solute in p-xylene revealed only an intramolecular process.

In general, a more viscous solvent seems of good potential for dielectric studies of flexible molecules. The solutes examined here have a much greater T~/TZ ratio than with solvents of appreciably lower viscosity. Such a higher ratio should lead to a more favourable analysis for molecules in which molecular orientation makes a smaller contribution to the dielectric absorption.