Synthesis, spectra, redox property and catalytic activity of ruthenium(III) Schiff base complexes

705-709A series of ruthenium(llI) complexes of the type [RuX2(EPh3)2(L)] (where E= P or As, X= CI or Br; L = bidentate Schiff bases) have been synthesized and characterized on the basis of analytical (elemental analysis, magnetic susceptibility) and spectral methods (FT-IR, UY-vis, EPR). EPR spectra of the powdered samples exhibit three lines with different 'g' values indicating a rhombic distortion in these complexes. Cyclic voltammogram of the complexes displays one reversible oxidation (RuIV/RuIII) and two reversible reduction peaks (RuIII/RuII, RuII/RuI) with ∆EP mV suggesting one electron transfer process. These complexes effectively catalyze the oxidation of primary alcohols to their corresponding aldehydes up to 91.5% in the presence of N-methylmorpholine-N-oxide (NMO) as co-oxidant. The formation of high-valent Run+2=O species as catalytic intermediate is proposed for the catalytic processes