Mixed ligand complexes of palladium(II) and platinum(II) with methionine and purines

106-109Mixed ligand complexes of Pt(II) and Pd(II) with methionine (MetH) as primary ligand and purinesadenine, guanine and hypoxanthine-as secondary ligands have been prepared by reacting cis-[Pd(MetH)CI2] (1) and cis- [Pt(MetH)CI2] (2) with adenine, guanine and hypoxanthine in 1: 1 molar ratio. The complexes have been characterized on the basis of analytical, conductivity, and IR, electronic and 1H NMR spectral data. In these complexes methionine is bound to the metal ion through amino nitrogen and sulphur atoms. The purines are bound to the metal ion through nitrogen (N7) of the five-membered ring and are present in a configuration trans to methionine sulphur. This indicates a higher trans directing ability of sulphur compared to that of amino nitrogen of methionine. Conductivity data show that the complexes are 1:1 electrolytes