Studying the Thermodynamics and Kinetics of Ion Transfers Across Water-2-nitrophenyloctyl Ether Interface by Means of Organic-solution-modified Electrodes

Abstract

Transfer reactions across a water-2-nitrophenyloctyl ether (W|NPOE) interface for a series of monovalent inorganic ions and tetraalkylammonium cations are studied by means of square-wave (SWV) and cyclic voltammetry at thin organic-film-modified (TFE) and three-phase electrodes (TPE). Both electrode configurations are assembled using lutetium bis(tetra-tert-butylphthalocyaninato) as the redox probe, whose properties enable assessment of both anion and cation transfer reactions in a single voltammetric experiment. It is demonstrated that TFE can be effectively applied to measure the Gibbs energy of ion transfer reactions when the transferring ion is common to both liquid phases, controlling the Galvani potential difference at the W|NPOE interface. A comparative study of the thermodynamics of ion transfer reactions performed with TFE and TPE reveals that both electrode configurations provide a consistent set of data. Kinetic measurements referring to the transfers of ClO4−, and a series of tetraalkylammoniu...