Syntheses, characterization and luminescence of Pt-M (M = Re, Ru, Gd) heteronuclear complexes with 5-ethynyl-2,2 '-bipyridine

Incorporation of diplatinum component [Pt-2(mu-dppm)(2)(C Cbpy)(4)] (1, dppm = Ph2PCH2PPh2, C Cbpy = 2,2'-dipyridyl-5-acetylide) with Re(CO)(5)Cl, Ru(bpy)(2)Cl-2 (bpy = 2,2'-bipyridine) and Gd(hfac)(3)(H2O)(2) (Hhfac = hexafluoroacetylacetone) via 2,2'-dipyridyl chelating induced isolation of (Pt2Ru4II)-Ru-II (2), (Pt2Ru4II)-Ru-II (3), and (Pt2Gd2III)-Gd-II (4) complexes, respectively. The structures of 2 and 4 were determined by X-ray single crystal diffraction. Intense low-energy absorptions occur in the range 360-510 nm originating from metal-to-ligand charge transfer (MLCT) transitions. These compounds display photoluminescence in both solid states and dichloromethane at room temperature with emissive lifetimes in the range of microseconds. (c) 2006 Elsevier B.V. All rights reserved.