Aerobic oxidative dehydrogenations catalyzed by the mixed-addenda heteropolyanion PV2Mo10O405-: A kinetic and mechanistic study

Article abstract of DOI:10.1021/ja00044a044

The aerobic oxidative dehydrogenation of α-terpinene to p-cymene catalyzed by the mixed-addenda heteropolyanion PV₂Mo₁₀O₄₀^5- has been used to investigate the oxidation mechanism catalyzed by this class of compounds. The kinetics of the reaction show it to be zero order in α-terpinene, first order in dioxygen, and second order in the heteropolyanion catalyst. The kinetic results along with the use of UV-vis, ESR, ³¹P NMR, and IR spectroscopy have enabled the formulation of a reaction scheme involving the formation of a stable substrate-catalyst complex in the catalyst reduction (substrate oxidation) stage and a μ-peroxo catalyst intermediate in the catalyst reoxidation where dioxygen is reduced to water in a four-electron redox reaction.