INFLUENCE OF SODIUM DODECYL-SULFATE MICELLES ON THE KINETICS OF COMPLEX-FORMATION BETWEEN PD(H2O)(4)(2-CARBOXYMETHYL-L-CYSTEINE() AND S)

The kinetics of complex Formation between Pd(H(2)0)(4)(2+) and S-carbo xymethyl-L-cysteine (SCMCH(2)) was investigated in the presence of sod ium dodecyl sulphate in the acidity range between 2 M HClO4 and pH 5. Although the mechanism was not affected by the presence of anionic mic elles, retardation (2.2<pH<5) and acceleration (pH<2.2) of the complex formation were observed compared with its rate in aqueous solution. T hese effects were interpreted in terms of the long-range electrostatic interactions between the negatively charged micellar surface and liga nd species which can be in different ionic forms depending on the pH.