A symmetrical flexible bis(phosphinoferrocene) derivative, viz. bis[1'-(diphenylphosphino)ferrocenyl]methane (1), was prepared and studied as a ligand in Pd(II) and Au(I) complexes. The reactions of 1 with [PdCl2(cod)] (cod = cycloocta-1,5-diene) and [Pd(mu-Cl)(L-NC)](2) (L-NC = [2-(dimethylamino-kappa N) methyl] phenyl-kappa C-1) produced bis(phosphine) complex trans-[PdCl2(1-kappa P-2, P')] (4), wherein the ligand spans trans positions in the square-planar coordination sphere of Pd(II) and the tetranuclear, P, P-bridged complex [(mu(P, P')-1){PdCl(L-NC)}(2)] (5), respectively.
In reactions with the Au(I) precursors [AuCl(tht)] and [Au(tht)(2)][SbF6] (tht = tetrahydrothiophene), ligand 1 gave rise to tetranuclear Au2Fe2 complex [(mu(P, P')-1)(AuCl)(2)] (6) and to symmetrical macrocyclic tetramer [Au-4(mu(P, P')-1)(4)][SbF6](4) (7). All compounds were characterized by spectroscopic methods.
In addition, the structures of compound 1, its synthetic precursor bis[1'-(diphenylphosphino) ferrocenyl] methanone (3), and all aforementioned Pd(II) and Au(I) complexes were determined by single-crystal X-ray diffraction analysis (some in solvated form).