Reactions of Bis(chalcogenolato) Complexes [(η5-C5Me5)Ir(CO)(ETol)2] (E = Se, S; Tol = p-Tolyl) with [Pt(PPh3)3]. Formation of Tri- or Dinuclear Mixed-Metal Complexes with Bridging Chalcogenido or Chalcogenolato Ligands

Treatment of [Cp*Ir(CO)(SeTol)(2)] (Cp* = eta(5)-C5Me5, Tol = p-tolyl) with 2 equiv of [Pt(PPh3)(3)] in toluene at reflux resulted in the insertion of Pt(PPh3) groups into Se Tol bonds to give the triangular cluster with capped Se ligands [Cp*Ir(mu(3)-Se)(2){PtTol(PPh3)}(2)] (5). By stirring under CO atmosphere, Sin solution was readily converted to [Cp*Ir(CO)(mu(3)-Se)(2){PtTol(PPh3)}(2)] (2b), which returned to 5 in toluene at reflux. On the other hand, reaction of [Cp*Ir(CO)(STol)(2)] with an equimolar amount of [Pt(PPh3)(3)] afforded the thiolato-bridged dinuclear complex [Cp*Ir(CO)(mu-STol)Pt(STol)(PPh3)] (6) through the insertion of the Pt center into the Ir-S bond, and that with 2 equiv of [Pt(PPh3)31 in toluene at reflux led to the incorporation of the second Pt fragment to the core of 6 to give the thiolato-bridged triangular cluster [Cp*Ir{Pt(PPh3)}(2)(mu(2)-CO(mu(2)-STol)(2)] (7). An X-ray diffraction study has been carried out to determine the detailed structures of 21), 5, 6, and [Cp*Ir{Pt(PPh3)},(mu(2)-CO)(mu(2)-SPh)(2)], which is the SPh analogue of 7.