Interaction of PdCl 4 2- with L-cystine in hydrochloric acid solutions

The effect of acidity and equilibrium chloride ion concentration on the interaction of PdCl4 2- with cystine (H2CySS) in hydrochloric acid solutions was studied. Pd(H4CySS)Cl3+ complex was found to form at [Cl–] = 1.0, 0.5, or 0.25 mol/Linthe [H+] range from 0.10 to 1.00 mol/L; the relevant equilibrium constant was determined. Monodentate coordination of cystine to palladium(II) through the sulfur atom was proposed on the basis of analysis of conditional stability constants as functions of [Cl–] and [H+].