Reaction of triangulo-clusters [Pt3(μ-CO)3(PR3)3] with hexafluorobutyne. The X-ray crystal structures of [Pt2(CO)2(PR3)2(μ-η2:η2-CF3CCCF3)](PR3= PPh3 or PCy3) and [Pt2(CO)2(PBzPh2)(μ-η1:η1-CF3CCCF3)2]

Hexafluoro-2-butyne, CF3CCCF3, reacts with the triangulo-clusters [Pt3(μ-CO)3(PR3)3] to give the diplatinum(0) compounds [Pt2(CO)2(PR3)2(μ-η2:η2-CF3CCCF3)] {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-CF3CCCF3)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.