Electron-Transfer Studies of Model Redox-Active Species (Cationic, Anionic, and Neutral) in Deep Eutectic Solvents

Renjith, A and Lakshminarayanan, V (2018) Electron-Transfer Studies of Model Redox-Active Species (Cationic, Anionic, and Neutral) in Deep Eutectic Solvents. In: Journal of Physical Chemistry C, 122 (44). pp. 25411-25421.

PDF jou_phy_che_C_122-44_25411-25421_2018.pdf - Published Version Restricted to Registered users only Download (2MB) | Request a copy

Abstract

The redox potentials of electroactive species are significantly influenced by the solvation characteristics of the medium. This is manifested in the shift of half-peak potentials with the change in the solvent medium. There have been many approaches till date, both experimental and theoretical to understand the role of molecular solvents in the peak potentials of redox species. The electrochemical studies reported here are aimed at understanding the effect of deep eutectic solvents (DESs) which is distinct from conventional solvents in terms of highly concentrated ionic composition, on the half-peak potentials of some standard redox reactions. The redox species selected for this study are distinct either in terms of their charge Fe(CN)6 4-/3-, Ru(NH3)6 2+/3+, and ferrocene methanol, FcMeOH0/+ or their hydrophilic/hydrophobic properties methyl viologen and ferrocene. The redox potentials are compared with the values obtained in the aqueous medium which is very well characterized in terms of solvent reorganization energy and free-energy changes. The cyclic voltammetric behavior of the redox species in DES is significantly different from that of aqueous medium. The diffusion coefficients of the redox species in DES measured by EIS and cyclic voltammetry showed significant deviations from that predicted by Stokes-Einstein equation, indicating the dominant effect of Coulombic interactions within the components of DES.

Item Type:	Journal Article
Publication:	Journal of Physical Chemistry C
Publisher:	American Chemical Society
Additional Information:	The copyright for this article belongs to the American Chemical Society.
Keywords:	Ammonia; Cyclic voltammetry; Eutectics; Free energy; Hydrophilicity; Ionic liquids; Iron compounds; Organometallics; Solvents, Coulombic interactions; Cyclic voltammetric; Deep eutectic solvents; Electroactive species; Electrochemical studies; Hydrophilic/hydrophobic; Solvent reorganization energy; Stokes Einstein equations, Redox reactions
Department/Centre:	Division of Electrical Sciences > Electronic Systems Engineering (Formerly Centre for Electronic Design & Technology)
Date Deposited:	05 Aug 2022 05:38
Last Modified:	05 Aug 2022 05:38
URI:	https://eprints.iisc.ac.in/id/eprint/75158

Actions (login required)

View Item