Reaction of triangulo-clusters (see abstract)

Article abstract of DOI:10.1039/b203075f

Hexafluoro-2-butyne, CF₃C≡CCF₃, reacts with the triangulo-clusters [Pt₃(μ-CO)₃(PR₃)₃] to give the diplatinum(o) compounds [Pt₂(CO)₂(PR₃)₂ (μ-η²:η² -CF₃ C≡CCF₃)] {PR₃ = PPh₃ (1), PBzPh₂ (2), PCy₃ (3), PⁱPr₃ (4)}. Spectroscopic properties are reported which are in accord with the molecular structures for 1 and 3, both having the acetylenic C-C axis perpendicular to the Pt-Pt axis, bridging two [Pt(CO)(PR₃)] fragments in a μ-η²:η² fashion. A large excess of hexafluorobutyne slowly converts 1 and 2 to the diplatinum(II) complexes [Pt₂(CO)₂(PR₃)₂ (μ-η¹:η¹-CF₃C≡CCF₃) ₂] {PR₃ = PPh₃ (5), PBzPh₂ (6)}, having two planar hexafluorobutyne bridges. This stereochemistry has been established by NMR and IR spectra, and confirmed by single-crystal X-ray diffraction.