Electrochemical Study of Complex Formation of Cerium (IV) Ion with Glycyl-Glycine and Glycyl- Valine

Cyclic voltammetry can be used to determine the relative stability of Ce4+ll+complexes which has been less accessible by other techniques. Shifts in the anodic and cathodic peak potentials of Ce4+!J+-L and the reversibility of the electrochemical processes were studied as a function of concentration of the ligands. The cyclic voltammograms of Ce4+/l+ obtained at different scan rates are quasireversible with a formal redox potential of E1/2= 0.95975 V in 0.5 M H2S04 solution. The voltammograms of Ce4+/J+-glycyl-glycine(Ce4+/J+_glygly) and Ce4+/3+ - glycyl- valine (Ce4+/J+ -gly val) show a reduction wave negatively shifted relative to the reduction wave of Ce4+/J+. The reversibility of the Ce4+ICeJ+ couple improved with the increase of scan rates.