Reactivity of Peroxopolyoxo Complexes. Oxidation of Thioethers, Alkenes, and Sulfoxides by Tetrahexylammonium Tetrakis( diperoxomo1ybdo)p hosp hate

Kinetics of oxidation of thioethers, alkenes, and sulfoxides by tetrahexylammonium tetrakis(diperoxomo1ybdo) phaephate (TEAM) were performed in chloroform. The results obtained, compared with the correaponding data of a series of Mo(V1) peroxo complexes, rule out a nucleophilic oxygen transfer mechanism. Rather, the data point to Mo(VI) peroxopolyoxo complexes as well as simple peroxo complexes behave as electrophilic oxidants toward nucleophilic substrates such as thioethers and alkenes. A study of the countercation effects indicates that the increasing bulkiness of the cation reduces the electrophilicity of the peroxopolyoxo complex. With sulfoxides, incursion of SET processes might be a likely event.