Triphos as a bidentate ligand: the reactivity of the dangling phosphorus in [PtMe2(triphos-P,P′)]

Complex PtMe₂(triphos-P,P′)], (1) where the linear triphosphine triphos =bis(diphenylphosphinoethyl)phenylphosphine] acts as a bidentate ligand, can be easily converted in a variety of new complexes due to the reactivity of the free phosphorus donor. The selective oxidation of the uncoordinated phosphorus gave PtMe₂(triphosPO-P,P′)] whose X-ray crystal structure is here reported; from the reactions of 1 with platinum and non platinum precursors homotrimetallic Pt₃Me₄XY(triphos)₂] (X=Y=Me, Cl, I, X=Me, Y=Cl) and heterotrimetallic (Pt₂PdMe₄Cl₂(triphos)₂] and Pt₂RhMe₄(cod)(triphos)₂]PF₆) complexes were obtained where triphos acts as a chelating/bridging ligand. When 1 was treated with triflic acid in the presence of a neutral electron donor L (L=SMe₂, pyridine, PPh₃), complexes PtL(triphos)]²⁺ were rapidly recovered in high yields. The protonolysis of 1 in the presence of CO and methanol gave the new organometallic complex Pt(COOMe)(triphos)]OTf.