Synthesis, structures, and catalytic oxidation of three aqua-coordinated and oxo-bridged diruthenium(III) complexes with sulfobenzoate and 2,2-bipyridine

Three new diruthenium(III) complexes, [Ru2O(2-sb)(2)(2,2'-bipy)(2)(H2O)(2)]center dot 2.5H(2)O (1), [Ru2O(3-sb)(2)(2,2'-bipy)(2)(H2O)(2)]center dot 9H(2)O (2), and [Ru2O (4-sb)(2)(2,2'-bipy)(2)(H2O)(2)]center dot 9H(2)O (3), where sb(2-) is sulfobenzoate dianion and 2,2'-bipy is 2,2'-bipyridine, were synthesized using hydrothermal methods and characterized by IR, elemental analysis, thermogravimetric analysis, UV-vis, and fluorescence spectra. The single crystal X-ray analysis showed that each of these complexes has a dinuclear core stabilized by two bridging carboxylates and one bridging O2-. Variable sb(2-) ligands (2-sb, 3-sb, and 4-sb) in these complexes lead to diverse electronic spectroscopic behavior. The efficiency of activating methyl phenyl sulfide oxidation utilizing H2O2 in 3 equiv. was studied at 23 +/- 2 degrees C. The effect of the amount of catalyst and solvents on activities was investigated. Under optimized reaction conditions, the major product was sulfoxide. Complex 1 gave significant conversion of 100 and 98% selectivity for sulfoxide after 4h.