title: Energy-gaining formation and catalytic behavior of active structures in a SiO(2)-supported unsaturated Ru complex catalyst for alkene epoxidation by DFT calculations.
abstract: The formation and catalytic behavior of active structures in a SiO(2)-supported unsaturated Ru complex catalyst for alkene epoxidation were studied by means of hybrid density functional theory (DFT) calculations. An energy-gaining route for the catalyst activation was found to allow the formation of active unsaturated Ru complexes and the remarkable alkene epoxidation via an exothermic reaction path between isobutyraldehyde and oxygen. In the proposed Bartlett mechanism, Ru promotes the formation of peracid intermediate and facilitates the intermolecular hydrogen transfer in the peracid intermediate, while alkene molecules do not directly coordinate to the Ru site. It was found that stilbene epoxidation is easier to achieve than ethene epoxidation thanks to the electron donating phenyl groups.
authors.affiliation: Department of Chemistry, Graduate School of Science, The University of Tokyo, Hongo, Tokyo, Japan.
authors.forename: Rudy
authors.initials: R
authors.lastname: Coquet
authors.forename: Mizuki
authors.initials: M
authors.lastname: Tada
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Iwasawa
mesh_terms: D000447:Aldehydes / Q000737:chemistry; D000475:Alkenes / Q000737:chemistry*; D001665:Binding Sites; D002384:Catalysis; D004583:Electrons; D004852:Epoxy Compounds / Q000138:chemical synthesis*; D006859:Hydrogen / Q000737:chemistry; D008958:Models, Molecular; D009942:Organometallic Compounds / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry; D012428:Ruthenium / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D000447:Aldehydes; D000475:Alkenes; D004852:Epoxy Compounds; D009942:Organometallic Compounds; D012822:Silicon Dioxide; D012428:Ruthenium; D006859:Hydrogen; C017439:isobutyraldehyde; D010100:Oxygen