The study of the electroreductions Cd(II)/Cd(Hg) and Zn(II)/Zn(Hg) in solutions of methanol, formamide, acetonitrile and propylene carbonate, in the presence of suitable inhibitors, by the method of interfacial distance parameters at constant electrode coverage, combined with the method of steric factors of the activated complex and the inhibitor indicates a two step IA mechanism for both reactions and gives information about the structure of the activated complex at the various reaction sites. (C) 2004 Elsevier B.V. All rights reserved.