Electrochemical behaviour of the complexes formed by Pd(2), Cd(2) and Zn(2) with crotonate ions at a dropping mercury electrode

Electrochemical behaviour of the title complexes is studied. Reduction was found to be diffusion-controlled in all the cases, and quasi-reversible in the case of the Xn(2) - crotonate system. The composition and formation constants of the complexes formed have been calculated. In the case of the Zn(2) - crotonate system the Esub(1/2)sup(r) has been calculated by the Gelling method and used for the calculation of formation constants and the electrode kinetics. Both Cd(2) and Pb(2) form three complex species (MX1, MX2, and MX3), whereas Zn(2) are much stronger than those formed by Cd(2) and Zn(2). The per cent distribution of metal ions and their composition at various ligand concentrations have been calculated. (author)