Collection of Czechoslovak Chemical Communications - digital archive 

Abstract

The two-step reduction of Zn(II) ions at a dropping mercury electrode in 1 M NaClO₄ with addition of vetranal was examined using dc polarography, cyclic voltammetry and impedance measurements. Small changes of reversible potential of half-wave, E^r_1/2, values indicate that the Zn(II)-vetranal complexes formed in the solution are very unstable. A stepwise character of electron transfer in the Zn(II) ion reduction was established. The catalytic activity of vetranal is stronger in the first step of electron transfer than in the second one. The linear dependence of the true rate constant for the forward reaction, k^t_f, of Zn(II) electroreduction versus relative surface excess, Γ′, of vetranal at a given potential in the reaction plane, Φ^r, was interpreted in terms of a "bridging model".

Keywords: Catalytic activity; Zinc(II) electroreduction; Vetranal; Rate constants; Mercury electrode.

References: 30 live references.