Electrochemical studies of a Cu(II)-Cu(III) couple: Cyclic voltammetry and chronoamperometry in a strong alkaline medium and in the presence of periodate anions

Cyclic voltammetry and chronoamperometry of a Cu(II)-Cu(III) couple in a strong alkaline medium and in the presence of periodate anions are described. The effects of the pH value of the complex solutions, Cu concentration and scan rate on peak potential and peak current were investigated. It was shown that the redox reaction of the Cu(II)-Cu(III) couple was a quasi-reversible process with one electron transferred. The formal electrode potential (vs SCE) was similar to 0.37 V. The irreversibility of the electrode reaction increased with the decrease in the pH value of the complex solutions. Under our experimental conditions the diffusion coefficient of the diperiodatocuprate(II) anion was estimated to be ca. 3.29 x 10(-6) cm(2) s(-1). (C) 1997 Elsevier Science Ltd.