863-866The kinetics of the interaction of L-cysteine with [Pt(en)(H20)2]2+ has been studied spectrophotometrically as a function of [Pt(en(H20)2+], [L-cysteinel, pH and temperature. The reaction has been monitored at 230 nm, where the spectral difference is maximum although the λmax, of the L-cysteine saturated product is at 213 nm. The activation parameters have been evaluated from temperature coefficient of the reaction rates. The low value of ΔH# (61.1 kJ mol-1) and large negative value of ΔS# (- 83 J k-1 mol-1) indicate an associative mode of activation for the substitution process. The additional advantage of using aquaamine complexes as an amino acid binder is also discussed
