General synthesis of ferrocenylphosphine-bridged digold carboxylato complexes - Crystal and molecular structure of Au-2(eta(1)-CF3CO2)(2)(mu-dppf)center dot C6H14 (dppf=Fe(C5H4PPh2)(2))

Metathesis of Au2Cl2(mu-dppf) with Ag(RCO2) (R = CH3, CF3, C2H5 and C6H5) gives Au-2(eta(1)-RCO2)(2)(mu-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(mu-dppm) with Ag(CF3CO2) gives Au-2(eta(1)-CF3CO2)(2)(mu-dppm)Au2(eta 1-CF3CO2)2(mu-dppm) in 52% yield. X-ray single-crystal crystallographic diffraction analysis of Au-2(eta(1)-CF3CO2)(2)(mu-dppf).C6H14 shows that in the centrosymmetric dinuclear molecule, the Au(I) geometry is approximately linear(measured angle O-Au-P177.1(1)degrees) and the trifluoroacetate ligand is unidentate (C(18)-0(1) 1.267(4)Angstrom and C(18)-0(2/2a) 1.212(4)Angstrom). An intermolecular Au...Au interaction of 3.254(1)Angstrom links the molecules into an infinite zigzag chain running parallel to the c axis. Crystal data: Au-2(eta(1)-CF3CO2)(2)(mu dppf).C6H14, space group C2/c (No. 15), a = 15.325(3), b = 19.058(4), c = 15.373(3)Angstrom, P = 95.98(3)Angstrom, final R = 5.66% for 3784 observed reflections. (C) 1997 Elsevier Science S.A.