Thin‐Film Voltammetry of a Lutetium Bisphthalocyanine at Ionic Liquid|Water Interface

Abstract

At room temperature, tetraoctylphosphonium bromide is a viscous ionic liquid, this gel-like organic phase can be cast over a basal-plane graphite electrode (BPGE). Cyclic voltammetry at such a modified electrode, in contact with an aqueous solution have revealed one reversible oxidation and five reversible reduction steps for a Lu III bisphthalocyanine dissolved in the ionic liquid film, a proof that the highly reactive reduced species were protected from interaction with water in this highly lipophilic phase. It has also been shown that the redox properties are influenced by the ions in the aqueous phase, a property which has been attributed to ion-pairing effects; obviously, the ion transfers at the organic j aqueous interface has been ignored. Electrochemistry of Lu(III)[( t Bu) 4 Pc] 2 (cyclic voltammetry and square wave voltammetry) under similar conditions shows that the nature and concentration of the anion in the aqueous solution in contact with the ionic liquid film influences the potential of the electrode reaction. This can be attributed to variations of the interfacial potential and also because the organic phase is an anion exchanger. Moreover, SWV experiments suggest that the rate of the overall reaction varies with the nature and concentration of the anion of the aqueous electrolyte, which implies that the ion transfer through the organic j aqueous interface is slower than the electron exchange rate of the molecule at the surface of graphite.

Voltammetry Study of an Anti-HIV Compound by means of a Thin Organic Membrane

“…At this level, we cannot establish the fact that the system I/I exchanges one electron. In order to shed more light on these systems and gather more information (e.g., the number of the electrons exchanged), some few experiments were done using square wave voltammetry, a more sensitive method especially when one deals with membrane processes [26][27][28][29][30]. The SWV technique is one of the most advanced voltammetric methods unifying the advantages of CV and pulse voltammetric techniques.…”

Electric-double-layer potential distribution in multiple-layer immiscible electrolytes

“…Among others, the model developed in this Brief Report is relevant for all situations in which a thin electrolyte film covers a wall in the presence of a second immiscible electrolyte. Examples are electrochemical setups utilizing electrodes covered by a thin liquid film [10][11][12], for which the rate of electrode reactions is dictated by the EDL structure at the electrode surface (see [13] and references therein).…”