Repositori URV

Identificador: imarina:3665547

Handle: https://hdl.handle.net/20.500.11797/imarina3665547

Autores:
Jimenez-Lozano, PabloSkobelev, Igor Y.Kholdeeva, Oxana A.Poblet, Josep M.Carbo, Jorge J.

Resumen:
A DFT study revealed that the mechanism of alkene epoxidation with hydrogen peroxide catalyzed by Ti-containing polyoxometalates (POMs) depends on the Ti coordination environment: For rigid and hindered Ti centers, the unprecedented ¿-oxygen transfer from the titanium hydroperoxo species becomes favored over the ¿-oxygen one. Improving the model for catalyst description, the calculations were able to reproduce the Arrhenius activation energy values determined in kinetic studies. Unlike protonation, the possible ion-pairing between POMs and countercations has a minor effect on the electrophlicity of the catalyst and, consequently, on the activity of epoxidation.