VOLTAMMETRY OF ADSORBED MOLECULES - PART 1 - REVERSIBLE REDOX SYSTEMS

When strongly adsorbed or chemisorbed molecules behave ''ideally'' it is a relatively simple process to interpret linear sweep voltammograms and extract thermodynamic and kinetic information. Unfortunately it i s rare that the criteria for ideality are met and other models have to be developed from which to extract information about the adsorbed red ox system of interest. In the last 15-20 years models have been develo ped which allow for the influence of such factors as lateral interacti ons, adsorbed dipoles, a distribution of formal potentials, multiple r edox sites, interfacial potential distribution, ion pairing, and acid- base equilibria. These models are reviewed with an emphasis on the und erlying assumptions on which the each model was derived. Diagnostic cr iteria are provided from which it may be determined which of the above phenomena, if any, are effecting the voltammetric response.