SYNTHESES AND REACTIVITIES WITH OLEFINS OF RUTHENIUM(IV) OXO RUTHENIUM(II)-AQUA COMPLEXES THAT CONTAIN 2,6-BIS(N-PYRAZOLYLPYRIDINE)

The syntheses and reactivities with olefins of [Ru(II)(L3)(L2)OH2]2+ [ L3=2,6-bis(N-pyrazolyl)pyridine(bpp), 2,6-bis(3,5-dimethyl-N-pyrazolyl )pyridine (Me4bpp); L2=2,2'-bipyridine(bpy), 4,4'-dimethyl-2,2'-bipyri dine (Me2bpy)] are described. Their spectral and redox properties in a queous solution were investigated. Evidence for each one electron redo x process for the Ru(IV)-Ru(III) and Ru(III)-Ru(II) couples has been o btained. Oxidation of [Ru(II)(bpp)(bpy)OH2]2+ with Ce(IV) gave [Ru(IV) (bpp)(bpy)O]2+. The Ru(IV) = O complex is paramagnetic (mu(eff) = 2.82 ) and the complexes [Ru(L3)(L2)OH2]2+ are robust catalysts for the oxi dation of styrene, cyclohexene, and cyclooctene with cooxidant such as NaOCl. Product distributions and selectivities are discussed by varyi ng the number of the substituted-methyl group in the ring.