Complex-formation reactions of dicholoro(S-methyl-l-cysteine)palladium(ii) with bio-relevant ligands. Labilization induced by S-donor chelates

Abstract

The complex-formation equilibria of [Pd(SMC)(H₂O)₂]⁺, where SMC = S-methyl-L-cysteinate, with bio-relevant ligands such as amino acids, peptides, dicarboxylic acids and DNA constituents were studied and their formation constants were determined. The binding mode of the ligands containing various functional groups was studied and the speciation diagrams were evaluated. The kinetics of base hydrolysis of amino acid esters bound to [Pd(SMC)(H₂O)₂]⁺ was studied in aqueous solution at 25 °C and 0.1 M ionic strength. The effect of solvent polarity and temperature on the hydrolysis of coordinated glycine methyl ester was investigated. The activation parameters are evaluated and discussed.