Palladium clusters Pd4(SR)4(OAc)4 and Pd6(SR)12 (R = Bu, Ph): Structure and properties

The structures of the Pd 4 (SBu) 4 (OAc) 4 ( I ) and Pd 6 (SBu) 12 ( II ) palladium clusters are determined by the X-ray diffraction method. For cluster I : a = 8.650(2), b = 12.314(2), c = 17.659(4) Å, α = 78.03(3)°, β = 86.71(2)°, γ = 78.13(3)°, V = 1800.8(7) Å 3 , ρcalcd = 1.878 g/cm 3 , space group P , Z = 4, N = 3403, R = 0.0468; for structure II : a = 10.748(2), b = 12.840(3), c = 15.233(3) Å, α = 65.31(3)°, β = 70.10(3)°, γ = 72.91(3)°, V = 1767.4(6) Å 3 , ρ calcd = 1.605 g/cm 3 , space group P , Z = 1, N = 3498, R = 0.0729. In cluster I , four Pd atoms form a planar cycle. The neighboring Pd atoms are bound by two acetate or two mercaptide bridges (Pd…Pd 2.95–3.23 Å, Pd…Pd angles 87.15°–92.85°). In cluster II , the Pd atoms form a planar six-membered cycle with Pd···Pd distances of 3.09–3.14 Å, the PdPdPd angles being 118.95°–120.80°. The Pd atoms are linked in pairs by two mercaptide bridges. The formation of clusters I and II in solution is proved by IR spectroscopy and calorimetry. Analogous clusters are formed in solution upon the reaction of palladium(II) diacetate with thiophenol.