Post-electron-transfer chemical reactions

Therefore, some concise review of the conditions of formation and the physical and chemical properties of the most important inorganic ion radicals is in order here. Special attention ought to be given to their reactions with organic compounds, both in an initial uncharged form and in a post-electron-transfer form. 

With respect to chemical steps prior to the electron-transfer step, chrono-potentiometiy offers a convenient technique. The methods of measurement and the quantitative relationships are outlined in Chapter 4. Post-electron-transfer reactions to the electron-transfer step are most conveniently characterized by cyclic voltammetry (see Chapter 3). Although the techniques of cyclic voltammetry and chronopotentiometiy both provide a means for the qualitative detection of adsorption processes at an electrode, the coulostatic method and chrono-coulometry are the methods of choice for quantitative measurements of adsorption. 

The simplest situation is when the electron transfer is totally irreversible or when the rate of the electrochemical step is much larger than the rate of chemical reaction. For such situations a reverse peak is not observed. If a postelectron-transfer process destroys the product before the reverse scan occurs, the ratio of the cathodic peak current to the anodic peak current will be greater than unity. At low scan rates an anodic peak may not be observed, but becomes detectable after an increase in the scan rate. Relations have been developed to evaluate the rate constants for post-electron-transfer reversible chemical reactions [Eq. (3.36)] ... 

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