A newly designed variable temperature stationary and flow-through cell for in situ ESR-electrochemical experiments in solvents having either low or high dielectric constants

Abstract

Previously designed cells for ESR-electrochemical measurements have been limited in their range of applicability because of mutually exclusive constraints placed by the ESR cavity quality factor and/or electrochemical ohmic iR drop problems. In this paper a readily constructed ESR-electrochemical cell has been designed which enables simultaneous in situ ESR-voltammetric and ESR-controlled potential electrolysis experiments to be performed (i) in solvents of either low dielectric constant (dichloromethane) or high dielectric constant (water, ethanol), (ii) with platinum, mercury, gold, silver or other electrode materials, (iii) in either a stationary or flow-through configuration and (iv) at variable temperature. Results for the reduction of the methyl viologen dication to the ESR-active monocation radical are presented to demonstrate the performance of the ESR-electrochemical cell under a range of conditions and to determine both the ESR and voltammetric characteristics of the cell.