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

Abstract

Mixed 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 <em>cis- </em>[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 <em>trans </em>to methionine sulphur. This indicates a higher <em>trans </em>directing ability of sulphur compared to that of amino nitrogen of methionine. Conductivity data show that the complexes are 1:1 electrolytes.