Crystal structure and physical properties of a ruthenium(II) bipyridine dimethylsulfoxide complex

The complex [Ru(bpy)(2)(DMSO)C1]PF6, where bpy is 2,2'-bipyridine and DMSO is dimethylsulfoxide, crystallizes in the triclinic space group P (1) over bar (#2) with a = 8.873 (2), b = 12.805 (4), c = 12.864 (4) Angstrom, alpha = 97.76(3), beta = 106.45(2), gamma = 107.88(2); Z = 2, and d(calc) = 1.75 mg/m(3). The coordination geometry is that of a distorted octahedron with a cis-RuN4SCl arrangement of coordinating atoms. The four Ru-N distances to the bpy ligands are 2.082(5), 2.092(4), 2.044(4), and 2.078(5) Angstrom. T he Ru-Cl distance is 2.421(2) A and the Ru-distance to DMSO is 2.260(1) Ang strom. The Ru-N bond distance trans to Cl is the shortest; the Ru-N bond di stance trans to S is the longest. The complex is oxidized and reduced rever sibly at 1.13 and -1.37 V vs. SSCE, respectively. It displays electronic ab sorptions at 515, 480 (1.5 x 10(4)), 342 (1.5 x 10(4)), 292 (1.2 x 10(5)), and 240 nm (6.2 x 10(4)) and has a broad emission band centered at 607 nm a t 77 K in a 4:1 ethanol/methanol glass. The emission lifetime at room tempe rature is less than the pulse width of the laser, tau < 20 ns.