Reactivity of anionic metal carbonyl hydrides toward bis(diphenylphosphino)methane complexes of palladium and platinum

Abstract

The reaction between [PPN][HFe(CO) 4] or [PPN][HFeCr(CO) 9] and [PdPt(μ-dppm) 2Cl 2] ( 3) in THF have been shown to give the trimetallic cluster [FePdPt(μ-dppm) 2(CO) 4]; because of the residual acidity of the H ligand in the starting anions, they behave as precursors of [Fe(CO) 4] 2−. Hydride transfer followed by molecular rearrangement takes place in the reaction between [Et 4N][HM(CO) 5] (M  Cr, W) and [PtCl 2(dppm)], which give [Pt 2 (μ-H)(μ-dppm) 2H 2][MCl(CO) 5]. Products resulting from redox exchange and intermolecular dppm (and sometimes CO) transfer were isolated from the reactions of [Pd 2(μ-dppm) 2Cl 2] with Na 2[Cr 2(CO) 10] or [Et 4N][HCr(CO) 5], and of the latter anion with 3. Whereas reaction of this anion with trans-[PdCl 2(PEt 3) 2] led to reduction to palladium metal, trans-[PtCl 2(PEt 3 2] was converted into [Pt 4(μ-CO) 5(PEt 3 4] (79% yield).