Synthesis of Luminescent Gold(I) and Gold(III) Complexes with a Triphosphine Ligand

We have synthesized and characterized a series of trinuclear gold(I) complexes [(AuX)₃(μ-triphos)] (triphos = bis(2-diphenylphosphinoethyl)phenylphosphine; X = Cl 1, Br 2, I 3, C₆F₅ 4) and di- and trinuclear gold(III) complexes [{Au(C₆F₅)₃}_n(μ-triphos)] (n = 2 (5), 3 (6)). The crystal structure of 6 [{Au(C₆F₅)₃}₃(μ-triphos)] has been determined by X-ray diffraction studies, which show the triphosphine in a conformation resulting in very long gold−gold distances, probably associated with the steric requirements of the tris(pentafluorophenyl)gold(III) units. Complex 6 crystallizes in the triclinic space group P(−1) with a = 12.7746(16) Å, b = 18.560(2) Å, c = 21.750(3) Å, α = 98.215(3)°, β = 101.666(3)°, γ = 96.640(3)°, and Z = 2. Chloride substitutions in complex 1 afford trinuclear gold(I) complexes [(AuX)₃(μ-triphos)] (X = Fmes (1,3,5-tris(trifluoromethyl)phenyl) 7, p-SC₆H₄Me 8, SCN 9) and [Au₃Cl_3-n(S₂CNR₂)_n(μ-triphos)] (R = Me, n = 3 (10), 2 (12), 1 (14); R = CH₂Ph, n = 3 (11), 2 (13), 1 (15)). The luminescence properties of these complexes in the solid state have been studied; at low temperature most of them are luminescent, including the gold(III) derivative 6, with the intensity and the emission maxima being clearly influenced by the nature and the number of the ligands bonded to the gold centers.