Salts of the type (NEt 3H)[Fe 2(CO) 6(μ-CO)(μ-SR)] (R=1cr; iPr, tBu, Ph) react with [ClAuPPh 3] in the presence of TIBF 4 to produce the neutral iron-gold clusters [Fe 2(CO) 6(μ-CO)(μ-SR)(μ-AuPPh 3)] (R=1cr; iPr, 1; R=1cr; tBu, 2; R=1cr; Ph, 3) in high yields. The structure of 1 has been determined by X-ray diffraction methods. Crystals are monoclinic, space group P2 1/ c, with a = 11.373(1), b = 14.899(3), c = 17.997(8) Å, β = 95.12(2)° and Z = 4, R = 0.030 and R′ = 0.035 for 3579 unique reflections with I ⩾ 2σ( I). The basic skeleton consists of an Fe 2Au triangle where the FeFe bond is bridged by a carbonyl and a thiolate group. In contrast, the reaction of the salts (NEt 3H)[Fe 2(CO) 6(μ-CO)(μ-SR)] (R = Et or C 6F 5) with [ClAuPPh 3] does not afford the corresponding mixed iron-gold clusters, and the diiron mono- or di-substituted complexes [Fe 2(CO) 5 (PPh 3)(μ-SR) 2] (R=1cr; Et, 4; R=1cr; C 6F 5, 5) and [Fe 2(CO) 4(PPh 3) 2(μ-SEt) 2] ( 6) are obtained instead. The structure of 4 has been established by single-crystal X-ray diffraction studies. Crystals are triclinic, space group, P 1 , with a = 10.472(4), b = 11.329(2), c = 13.437(2) Å, α = 80.34(2), β = 92.62(3), γ = 114.46(2)°, and Z = 2, R = 0.027 and R′ = 0.030 for 3732 unique reflections with I ⩾ 2σ( I). The FeFe bond in 4 is almost symmetrically double-bridged by two thiolate ligands and the phosphine group attached to the Fe(1) is trans to the iron-iron bond.