DIOXOMOLYBDENUM(VI) HALIDES AS OXOTRANSFER CATALYSTS

The catalytic activity of [MoO(2)X(2)(DMSO)(2)] (X = F, Cl, Br; DMSO= dimethylsulphoxide) in both the oxidation of triphenylphosphine (PPh(3 )) by DMSO and the deoxygenation of azoxybenzene by PPh(3) has been ex amined. While [MoO2F2(DMSO)(2)] was nearly inactive, [MoO2Cl2(DMSO)(2) ] proved to be an excellent catalyst. The oxotransfer reactions from [ MoO2Cl2(DMF)(2)] (DMF = dimethylformamide) to PPh(3), and from DMSO to [MoOCl2(DMF)(2)], in DMF at 25 degrees C, follow a second-order kinet ic law with rate constants k =(4.3 +/- 0.1) x 10(-2) and k = (8.7 +/- 0.2) x 10(-2) M(-1) s(-1), respectively.