Oxidation chemistry of 4-hydroxy and 5-hydroxyindoles in micellar medium

摘要

Oxidation of 4-hydroxyindole and 5-hydroxyindole has been studied in phosphate buffers of pH 3.0 and 7.0 at a pyrolytic graphite electrode in aqueous and micellar media. At both the pH, the presence of surfactants below critical micelle concentration (CMC) causes the splitting of peak Ii_a involving an overall 4e, 4H~+ per mole of 5-hydroxyindole into two 2e, 2h~+ oxidation peaks. At concentration of surfactants above CMC, two oxidation peaks again merged into single 2e, 2H~+ oxidation peak. In case of 4-hydroxyindole a single le, 1H~+ oxidation peak is not affected by the presence of the surfactants. The products of the electrode reaction have been characterized and were found identical in aqueous and micellar media.