Metal complexes with mono- and bis{[bis(2-pyridyl)amino]carbonyl}ferrocene ligands

The ligands {[bis(2-pyridyl)amino]carbonyl}ferrocene (L1) and 1,1'-bis {[bis(2-pyridyl)amino]carbonyl}ferrocene (L2) have been prepared by treatment of the mono- or 1,1'bis(chlorocarbonyl)ferrocene derivatives with dipyridylamine in a 1:1 or 1:2 ratio, respectively. The ligand properties of these compounds towards group 11 and palladium complexes have been studied. Ligand L1 coordinates to these compounds to give four-coordinate [Cu(L1)(2)](+), [PdCl2(L1)] and [Ag(OTf)(L1)(PR3)] or three-coordinate [Ag(OTf)(L1)] and [Au(C6F5)(L1)] compounds. The ligand coordinates in a chelate fashion in all cases. The reactivity of L2 is somewhat different because coordination to copper or silver atoms can take place through several pyridine units either from different cyclopentadienido rings, as in [Cu(L2)](+), [Ag-2(OTf)(2)-(L2)] and [Ag(OTf)(L2)(PPh3)], or from the same cyclopentadienido ring, as in [Ag-2(OTf)(2)(L2)(PPh3)], Coordination as a bridging ligand for four gold atoms has also been achieved in [Au-4(C6F5)(4)(L2)] and [Au-4(L2)(PPh3)4](OTf)(4). The ligands and some complexes have been characterized by Xray diffraction studies and show the presence of several hydrogen bonds that lead to supramolecular structures. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008).