WO_(3-X)(W-l)was used to achieve controllable photoisomerization of linear olefins without substituents under 625 nm light irradiation.Thermodynamic and kinetic isomers were obtained by regulating the carbon chain len...WO_(3-X)(W-l)was used to achieve controllable photoisomerization of linear olefins without substituents under 625 nm light irradiation.Thermodynamic and kinetic isomers were obtained by regulating the carbon chain length of the olefins.Terminal olefins were converted into isomerized products,and the internal olefin mixtures present in petroleum derivatives were transformed into valuable pure olefin products.Oxygen vacancies(OVs)in W-1 altered the electronic structure of W-1 to improve its light-harvesting ability,which accounted for the high activity of olefin isomerization under light irradiation up to 625 nm.Additionally,OVs on the W-1 surface generated unsaturated W^(5+)sites that coordinated with olefins for the efficient adsorption and activation of olefins.Mechanistic studies reveal that the in situ formation of surface Ti-complexes and ir-allylic W intermediates originating from the coordination of coordinated unsaturated W^(5+)sites and olefins ensure high photocatalytic activity and selectivity of W-1 for the photocatalytic isomerization of olefins via a radical mechanism.展开更多
This review focuses on the evolution of the use of osmium complexes as catalysts in the hydrogenation and isomerization of olefins.Osmium systems show good catalytic activities and selectivities in the hydrogenation o...This review focuses on the evolution of the use of osmium complexes as catalysts in the hydrogenation and isomerization of olefins.Osmium systems show good catalytic activities and selectivities in the hydrogenation of olefins via both dihydrogen and transfer hydrogenation.Such systems therefore have significant potential to become a powerful tool in organic synthesis.展开更多
文摘WO_(3-X)(W-l)was used to achieve controllable photoisomerization of linear olefins without substituents under 625 nm light irradiation.Thermodynamic and kinetic isomers were obtained by regulating the carbon chain length of the olefins.Terminal olefins were converted into isomerized products,and the internal olefin mixtures present in petroleum derivatives were transformed into valuable pure olefin products.Oxygen vacancies(OVs)in W-1 altered the electronic structure of W-1 to improve its light-harvesting ability,which accounted for the high activity of olefin isomerization under light irradiation up to 625 nm.Additionally,OVs on the W-1 surface generated unsaturated W^(5+)sites that coordinated with olefins for the efficient adsorption and activation of olefins.Mechanistic studies reveal that the in situ formation of surface Ti-complexes and ir-allylic W intermediates originating from the coordination of coordinated unsaturated W^(5+)sites and olefins ensure high photocatalytic activity and selectivity of W-1 for the photocatalytic isomerization of olefins via a radical mechanism.
文摘This review focuses on the evolution of the use of osmium complexes as catalysts in the hydrogenation and isomerization of olefins.Osmium systems show good catalytic activities and selectivities in the hydrogenation of olefins via both dihydrogen and transfer hydrogenation.Such systems therefore have significant potential to become a powerful tool in organic synthesis.
