The Influence of Lanthanoid Ions on the Polarographic Reduction Wave of Oxygen in Dimethyl Sulfoxide

Abstract

In the solutions containing both oxygen and one of the metal ions La³⁺, Pr³⁺, Eu³⁺, Dy³⁺, Ho³⁺, Yb³⁺, a new polarographic reduction wave was observed at about—0.5 V vs. SCE. The variation of the height and half-wave potential of this new wave were investigated as f unctions of the concentrations of oxygen and the various metal ions. Controlled current electrolysis was used to obtain information about the reduction process on the mercury and platinum electrodes. The reduction products, prepared by electrochemical method, were found to be the superoxides and peroxides of lanthanoids, for the platinum electrode and mercury electrode, respectively. On the basis of the results obtained it can therefore be presumed that the disproportionation reaction occurs on the mercury electrode.