Synthesis and characterization of platinum(II) and palladium(II) complexes of methionine and nucleosides

Abstract

A few binary complexes like <i>cis</i>-dichloromethionineplatinum( II), [Pt(MetH)Cl₂] and cis-dichloromethioninepalladium( II), [Pd(MetH)CI₂] react with the nucleosides, viz. adenosine, guanosine, inosine, and cytidine in a 1:1 molar ratio to form mixed ligand complexes. The complexes have been characterized on the basis of analytical, conductivity, infrared, electronic and ¹HNMR spectral data. In these complexes the metal ion is coordinated to methionine through amino nitrogen and sulphur atoms. The purine nucleosides are bound to the metal ion through the ring nitrogen (N₇) and the pyrimidine nucleoside through the ring nitrogen (N₃), in a configuration <i>trans </i> to methionine sulphur. The higher <i>trans </i> directing ability of sulphur as compared to that of amino nitrogen of methionine is responsible for this configuration.