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 [Au3Cl3-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.