COMPLEX-FORMATION REACTIONS OF DICHLORO(L-METHIONINATO)-PALLADIUM(II)WITH INOSINE AND INOSINE 5'-MONOPHOSPHATE - LABILIZATION INDUCED BY THE S-DONOR CHELATE

The kinetics and mechanism of the complex-formation reactions of [Pd(m et)Cl-2](-) (met=L-methionine anion) with inosine and inosine 5'-monop hosphate were studied in detail as a function of the chloride and nucl eophile concentrations. temperature and pressure in weakly acidic aque ous solutions. Two consecutive reaction steps which both depend on the nucleophile concentration were observed. A comparison with rate data for the corresponding ethylenediamine and substituted ethylenediamine complexes reveals the significant lability induced by the S-donor chel ate in [Pd(met)Cl-2](-). The reported activation parameters underline the operation of an associative ligand-substitution mechanism under al l conditions.