Osmium(II) bipyridine (bpy) complexes containing O,O-donor ligands and X-ray crystal structure of the acetylacetonato(acac) complex [Os(bpy) 2(acac)](PF6)

Article abstract of DOI:10.1016/j.molstruc.2011.03.063

The new complexes [Os¹¹(bpy)₂L](PF₆) [bpy = 2,2′-bipyridine; HL = acetylacetone (Hacac), trifluoroacetylacetone (Htfacac), hexafluoroacetylacetone, dibenzoylmethane or tropolone] have been prepared and the chemical oxidation of the [Os^II(bpy) ₂L]⁺ species (L = acac or tfacac) by aqueous S ₂O82- solution in the presence of (NH₄)PF₆ gave the reddish brown complexes [Os^III(bpy)₂L](PF ₆)₂. These complexes were characterized by spectroscopic measurements and also investigated by cyclic voltammetry. The X-ray crystal structure of [Os(bpy)₂(acac)](PF₆) (1) has been determined and showed that the complex has a distorted octahedral geometry in an environment of N₄O₂ donors. The reactivity toward oxidation of benzyl alcohol by complex (1) using H₂O₂ or other co-oxidants has been studied and compared with that of the related ruthenium(II) complexes.