名称:
Complexes of ruthenium(II) and (III) derived from O,N-donor ligands, and their efficiency as catalytic oxidants for alcohols
摘要:
The new complexes [Ru(II)Cl2(PPh3)2L] (L = benzoic hydrazide, bhz; substituted derivatives, R-bhz; R = p-Cl, p-CH3, omicron-NH2 and phenylacetic hydrazide) and [Ru(III)X2 (AsPh3)2L'] (L' = monoanions of 8-hydroxyquinoline, 8-hq; omicron-aminophenol, 2-amino-3-hydroxypyridine; X = Cl or Br) have been isolated. They were characterized by spectroscopic techniques and their redox behaviour was studied by cyclic voltammetry. The ruthenium(III) complexes were found to be more effective catalysts than those of ruthenium(II) for the oxidation of primary alcohols to aldehydes and of secondary alcohols to ketones in the presence of N-methylmorpholine-N-oxide as co-oxidant. Turnovers reached 400 with the catalyst [Ru(III)Cl2(AsPh3)2(8-hq)].