Concentration profiles as lability indicators for electrochemical systems containing metal complexes

Abstract

Electrochemical processes, involving mass transport of chemically interacting metal complexes and ligands, are considered using the quantitative model based on the second Fick’s law equations supplemented with kinetic terms. Concen­tration profiles obtained at different diffusion and kinetic parameters are used for the characterization of system lability. When chemical steps are fast enough and the interrelation between concentrations of species is specified by stability constants of metal complexes, all complexes in the system might be treated as electrically active species yielding the respective partial currents. In the case of the systems with limited lability, certain deviations from the equilibrium distribution of species is observed in the diffusion layer. The reaction layer concept is analysed and consideration is given to the feasibility of an idealized mass transport model in the electroanalysis.