Complex Heteropolytungstates as catalysts in the selective oxidation of diphenylsulfide to diphenylsulfoxide in presence of tert-butyl hydroperoxide

M G EGUSQUIZA; K BEN TALLEV; M MUÑOZ; G ROMANELLI; CABELLO C; I.L. BOTTO

Lille

Congreso; 6 th Word Congress on Oxidation Catalysis; 2009

The activity of complex heteropolytungstates of general formula  [MII4(H2O)2(PW9O34)2]10-(1) with M(II)= Co, Zn, Mn and Cu (PWM) was investigated in the selective oxidation of diphenylsulfide  to diphenylsulfoxide in presence of tert-butyl hydroperoxide as oxidant. The characterization was performed by XRD, DRS, FTIR and Raman. All phases are isomorphous, although PWCu is obtained as a mixture of (1) and two structural isomers. The reaction was carried out in batch at 80°C, in toluene, for 6 h. The diphenylsulfide conversions were 60-84% and selectivity to diphenylsulfoxide was ~95 %. PWCu was the most active catalyst. The activity was correlated with the oxidant character of the M(II).