KINETICS OF CHELATE FORMATION BETWEEN PD-II AND S-CARBOXYMETHYL-L-CYSTEINE

The kinetics of the complex formation between S-carboxymethyl-L-cystei ne and palladium(II) was studied by using stopped-flow technique in th e acidity range from pH 1 to 4 at 25 degrees C. The reaction rate of t he formation of 1 : 1 chelate species is strongly affected by the acid ity. The reaction mechanism consisting of five parallel paths which in volve Pd2+ and PdOH+, as well as LH-, LH2 and LH3+ ligand species was proposed. Fairly good agreement between the computed and experimentall y determined rate constants was found. The equilibrium constants of th e complex formation were determined. (C) 1998 Elsevier Science Ltd. Al l rights reserved.