The Coordination Behaviour of Ferrocene-based Pyridylphosphine Ligands towards AgI and AuI

Z. anorg. allgem. Chem.
Abstract. The reaction of the P,N-ligands [Fe(C₅H₄-PPh₂)(C₅H₄-2-py)] (1) (2-py = pyrid-2-yl), [Fe(C₅H₄-PPh₂)(C₅H₄-CH₂-2-py)] (2) and [Fe(C₅H₄-PPh₂)(C₅H₄-3-py)] (3) (3-py = pyrid-3-yl) with Ag[BF₄] in a 1:1 stoichiometric ratio afforded complexes of the type [Ag(L)][BF₄] (L = 1–3), which were structurally characterised by X-ray diffraction. Two structure types were observed in the solid state, viz. coordination polymer (L = 1, 2) and cyclic dimer (L = 2, 3). The reaction of1–3 with one equivalent of [AuCl(tht)] (tht = tetrahydrothiophene) afforded complexes of the type [AuCl(L-κP)] (L = 1–3), whose crystal structures were determined by X-ray diffraction. Their reactions with one equivalent of Ag[BF₄] gave products of the general composition [Au(L)][BF₄]; of these the cyclic dimer {[Au(μ-1)][BF₄]}₂ wasstructurally characterised by X-ray diffraction. The P,N,P-ligandC₅H₃N-2,6-(fcPPh₂)₂ (4, fc = 1,1′-ferrocenediyl) was synthesised by Negishi cross-coupling of Ph₂PfcZnCl with 2,6-dibromopyridine. Its crystal structure was determined by X-ray diffraction. The reaction of 4 with two equivalents of [AuCl(tht)] afforded the dinuclear gold(I) complex [(AuCl)₂(μ-4-κ²P,P)]. The mononuclear gold(I) complex [Au(4-κ²P,P)][SbF₆] was obtained in a one-pot reaction of 4 with one equivalent of [AuCl(tht)] and subsequently with one equivalent of Ag[SbF₆]; it contains 4 in a trans-chelating binding mode, as revealed by a crystal structure determination."