Solution infrared spectroelectrochemistry: A review.

Infrared (IR) spectroelectrochemical techniques have seen extensive use in studies of electrode surface processes. They have also been employed, albeit less frequently, to investigations of redox species dissolved in solution. The application of IR spectroscopy to electrochemical solution processes represents a special challenge, for absorption of IR radiation by the solvent is a significant interference to detection of vibrational modes of dissolved analytes. It is also difficult to maintain potentiostatic control of the system in specially designed thin-layer spectroelectrochemical cells. Solution IR spectroelectrochemical experiments are important for investigations of redox systems in which it is desired to spectroscopically monitor the structures of dissolved products, intermediates and reactants involved in electrode reactions. Such experiments have been conducted on biochemical, inorganic, organic, and other systems. In this paper some examples of applications of IR spectroelectrochemical studies of solution species in the above areas are presented, and experimental aspects are discussed.