A NOVEL TRIPEROXYNIOBIUM-CONTAINING POLYOXOANION, (SIW9(NBO2)3O37)-O-7- - SYNTHESIS, CHARACTERIZATION, CATALYTIC ALLYLIC EPOXIDATIONS WITH H2O2 AND PRELIMINARY KINETIC-STUDIES

The synthesis and characterization of the previously unknown SiW9(NbO2)3O377-, a novel composition of matter containing three adjacent NbvO2 peroxide groups, is described. Also reported is a survey of the catalytic epoxidation of seven olefinic substrates with 30% aqueous H2O2 Using this heteropolyanion as a precatalyst. Additionally, the preliminary kinetic evidence presented indicates that SiW9(NbO2)3O377- ServeS as a catalyst precursor to the true catalyst, a catalytically active W, Nb or polyoxoanion fragment.