Detection of interaction between redox centers of surface confined molecules by means of Cyclic Voltammetry and Differential Staircase Voltcoulommetry

Analytical expressions for the reversible electrochemical response of surface confined molecules with dependent or independent redox centers to Cyclic Voltammetry (CV, I–E curves) and Differential Staircase Voltcoulommetry (DSVC, dQ/dE–E curves), are presented and compared. The terms dependent and independent centers refer to those which are located inside the molecule at distances smaller or greater than a typical molecular diameter, respectively. In the case of dependent redox centers (stepwise processes), easy methods for characterising their intramolecular repulsive or attractive interactions are given.DSVC curves allow an effective de-coupling of the non-faradaic components of the response due to the discrete nature of the potential waveform used.Simple criteria for analyzing surface dependent and independent redox centers are given and experimentally tested obtaining surface coverages and the formal potential of each electroactive center.

► Electrochemical response of adsorbed multicenter redox molecules is analysed. ► The different interactions of molecules with dependent redox centers are analyzed. ► Simple criteria for characterising the surface electron transfer processes are given. ► Differential Staircase Voltcoulommetry reveals as a useful technique for these systems.