On the reactivity of platinum(IV) complexes: Synthesis and spectroscopic studies of platinum(IV) complexes with hypoxanthine

Na2[PtCl6] was found to react with (HypH)Cl·H2O (2) (Hyp=hypoxanthine) in aqueous solution at room temperature yielding (HypH)2[PtCl6] (3). The same compound was obtained from hexachloroplatinic acid and hypoxanthine. Performing this reaction in methanol at 50 °C complex formation took place yielding the hypoxanthine complex [PtCl4(Hyp)2] (4). Both compounds were isolated in good yields as faint orange (3) and yellow (4) precipitates, respectively and characterized by microanalyses, IR and NMR (1H, 13C, 195Pt) spectroscopies as well as thermal analysis. Based on the data obtained an octahedral molecular structure is proposed for complex 4 with two hypoxanthine ligands coordinated through N7 to platinum(IV).