Synthesis and characterization of heterodinuclear RuPt and IrPt complexes containing pyrazolate bridging ligands. Crystal structure of [(η5-C5Me5)Ir(μ-pz)3PtMe3] (pz=pyrazolate)

The reaction of the metallo–ligand [Ru(η6-p-cymene)(pz)2(Hpz)] with the platinum complex [{PtIMe3}4] affords mixtures of the heterodinuclear complexes [(η6-p-cymene)Ru(μ-pz)3PtMe3] (1) and [(η6-p-cymene)Ru(μ-pz)2(μ-I)PtMe3] (2). The reaction of the iridium derivative [Ir(η5-C5Me5)(pz)2(Hpz)] with [{PtIMe3}4] gives [(η5-C5Me5)Ir(μ-pz)2(μ-I)PtMe3] (3). Both [Ru(η6-p-cymene)(pz)2(Hpz)] and [Ir(η5-C5Me5)(pz)2(Hpz)] react with [{PtIMe3}4] in the presence of NaOH yielding 1 and [(η5-C5Me5)Ir(μ-pz)3PtMe3] (4), respectively. While [Ru(η6-p-cymene)(pz)2(Hpz)] reacts with [PtBr2Me2Sx] to give mixtures of [(η6-p-cymene)Ru(μ-pz)3PtBrMe2] (5) and [(η6-p-cymene)Ru(μ-pz)2(μ-Br)PtBrMe2] (6), the reaction of [Ir(η5-C5Me5)(pz)2(Hpz)] with [PtBr2Me2Sx] gives [(η5-C5Me5)Ir(μ-pz)2(μ-Br)PtBrMe2] (7) as the sole product. All species were characterized in solution by 1H-NMR spectroscopy. The crystal structure of complex 4 has been determined by single-crystal X-ray diffraction.