General synthesis of ferrocenylphosphine-bridged digold carboxylato complexes: Crystal and molecular structure of Au2(η1-CF3CO2) 2(μ-dppf) · C6H14 (dppf = Fe(C5H4PPh2)2)

Article abstract of DOI:10.1016/S0022-328X(97)00094-6

Metathesis of Au₂Cl₂(μ-dppf) with Ag(RCO₂) (R = CH₃, CF₃, C₂H₅ and C₆H₅) gives Au₂(η¹-RCO₂)₂(μ-dppf) in 75-97% yields. Spectroscopic data are consistent with a common structure containing a ferrocenyl diphosphine bridging two moieties of Au(I) bearing carboxylates in a unidentate coordination mode. Similar reaction of Au₂Cl₂(μ-dppm) with Ag(CF₃CO₂) gives Au₂(μ¹-CF₃CO₂)₂(μ-dppm) in 52% yield. X-ray single-crystal crystallographic diffraction analysis of Au₂(η¹-CF₃CO₂)₂(μ-dppf) · C₆H₁₄ shows that in the centrosymmetric dinuclear molecule, the Au(I) geometry is approximately linear (spherical angle O-Au-P 177.1(1)°) and the trifluoroacetate ligand is unidentate (C(18)-O(1) 1.267(4)A and C(18)-O(2/2a) 1.212(4)A). An intermolecular Au ... Au interaction of 3.254(1)A links the molecules into an infinite zigzag chain running parallel to the c axis. Crystal data: Au₂(η¹-CF₃CO₂)₂(μ-dppf) · C₆H₁₄, space group C2/c (No. 15), a = 15.325(3), b = 19.058(4), c = 15.373(3)A, β = 95.98(3)°, final R = 5.66% for 3784 observed reflections.