Novel heterotrinuclear, PtAg2, and hexanuclear, Pt2Ag4, compounds containing bridging alkynyl groups. Crystal structure of [Pt2Ag4(C6F5)4(µ3-η2-CCPh)4(PPh3)2]·0.5CH2Cl2

Abstract

Treatment of the polymeric derivatives [{PtAg₂(C₆F₅)₂(CCR)₂}_n](R = Ph or Bu^t) with 2 molar equivalents of neutral ligands L (Ag:L 1:1) afforded the new more soluble trinuclear mixed-ligand complexes [PtAg₂(C₆F₅)₂(CCR)₂L₂]1–8(L = PPh₃, PEt₃, CNBu^t or C₅H₅N). Analogous reactions with 1 molar equivalent of L (Ag:L 2:1) produced, however, only a partial depolymerization of [{PtAg₂(C₆F₅)₂(CCR)₂}_n] to give the hexanuclear complexes [Pt₂Ag₄(C₆F₅)₄(CCR)₄L₂]9–16. Compounds 9–12 have also been obtained by treatment of the binuclear derivatives [NBu₄][Pt(C₆F₅)₂(µ-CCR)₂AgL] with AgClO₄(1:1 molar ratio) in acetone. Similar reactions of [{PtAg₂(C₆F₅)₂(CCR)₂}_n] with 1 or 0.5 equivalent of 1,2-bis(diphenylphosphino)ethane (dppe) yielded insoluble complexes of composition [{PtAg₂(C₆F₅)₂(CCR)₂(dppe)}_n]17, 18 or [{Pt₂Ag₄(C₆F₅)₄(CCR)₄(dppe)}_n]19, 20 which are thought to be polymeric. The crystal structure of [Pt₂Ag₄(C₆F₅)₄(µ₃-η²-CCPh)₄(PPh₃)₂]·0.5CH₂Cl₂9·0.5CH₂Cl₂ has been determined by X-ray diffraction methods.