The compounds [PPh4][Ru(O)(2)(OCOR)Cl-2 (R=CH3 1a, CF3 1b, C6H5 Ic, C6F5 1d, C5H11 1e) were prepared and fully characterised. The fluorinated compounds lb and ld were obtained in significantly higher yields than their protonated analogues 1a and le and compound lb was found to be a clearly superior stoichiometric oxidant to compound 1a. The compounds 1a-1e were examined as catalytic oxidants for the oxidation of 1-and 2-hexanol, to hexanal and 2-hexanone respectively, with the co-oxidants H2O2, NaOCl, t-BuOOH, N-methylmorpholine-N-oxide, Me3NO, O-2, C6H5IO and BU4NIO4. Compounds 1c and 1d were further studied in the catalytic oxidation of a wide range of alcohols (using N-methylmorpholine-N-oxide and Bu4NIO4 as co-oxidants) and found to give the corresponding aldehydes or ketones very selectively, with no attack on sensitive linkages or functional groups and no over-oxidation products. Compounds 1c and 1d were also supported on poly(4-vinylpyridine) to give active catalysts. (C) 2007 Elsevier B.V. All rights reserved.