Redox kinetics measurements of probucole using square-wave voltammetry

Probucole is both electroactive and a surface-active compound. It undergoes fast and chemically reversible reduction ata HMD electrode in either 0.1 mol dm(-3) KClO4 or 1 mol dm(-3) KNO3. Both probucole and its electrode reduction product are strongly adsorbed to the electrode surface and the overall electrode mechanism exhibits characteristic properties of a surface redox reaction. The kinetics of the surface redox reaction of probucole is measured by means of square-wave voltammetry. The kinetic parameters of the redox reaction of probucole were estimated applying the methods of a split SW peak and a quasireversible maximum. In 1 mol dm(-3) KNO3, the standard rate constant is k(s) = 1400 +/- 30 s(-1) and the cathodic transfer coefficient is alpha = 0.55 +/- 0.02.