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

Incorporation of diplatinum component [Pt2(μ-dppm)2(CCbpy)4] (1, dppm = Ph2PCH2PPh2, CCbpy = 2,2′-dipyridyl-5-acetylide) with Re(CO)5Cl, Ru(bpy)2Cl2 (bpy = 2,2′-bipyridine) and Gd(hfac)3(H2O)2 (Hhfac = hexafluoroacetylacetone) via 2,2′-dipyridyl chelating induced isolation of Pt2IIRe4I (2), Pt2IIRu4II (3), and Pt2IIGd2III (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.

Graphical abstractBimetallic Pt2IIRe4I, Pt2IIRu4II, and Pt2IIGd2III complexes of 5-ethynyl-2,2′-bipyridine were prepared by incorporation of diplatinum complex Pt2(μ-dppm)2(CCbpy)4 with Re(CO)5Cl, Ru(bpy)2Cl2, and Gd(hfac)3(H2O)2, respectively, which afford room-temperature luminescence in both solid states and dichloromethane with emissive lifetimes in the range of microseconds.Figure optionsDownload full-size imageDownload as PowerPoint slide