The Ru(III) Schiff base complex, [Ru(L)Cl2|Cl; L = bis(picolinaldehyde) o-phenylenediimine, catalyzes the oxidation of secondary alcohols by N-methylmorpholine-N-oxide( NMO) or thallium) III) acetate as oxidant. Kinetic studies showed the formation of Ru(V) species as the active intermediate. © 1996 John Wiley & Sons, Inc.