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

Abstract

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)Å and C(18)-O(2/2a) 1.212(4)Å). An intermolecular Au ... Au interaction of 3.254(1)Å 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)Å, β = 95.98(3)°, final R = 5.66% for 3784 observed reflections. © 1997 Elsevier Science S.A.