1453-25-4Relevant articles and documents
Pines,Chen
, p. 3562 (1960)
Photocatalytic-controlled olefin isomerization over WO3–x using low-energy photons up to 625 nm
Sun, Xichen,Waclawik, Eric R.,Wang, Yunwei,Zhang, Jin,Zheng, Zhanfeng,Zhu, Pengqi
, p. 1641 - 1647 (2021/06/28)
WO3–x (W-1) 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 W5+ sites that coordinated with olefins for the efficient adsorption and activation of olefins. Mechanistic studies reveal that the in situ formation of surface π-complexes and π-allylic W intermediates originating from the coordination of coordinated unsaturated W5+ sites and olefins ensure high photocatalytic activity and selectivity of W-1 for the photocatalytic isomerization of olefins via a radical mechanism.
Substituent and Ring Size Dependence of the 4J(Me-C-C-H) Coupling Constant
Collins, M. J.,Hatton, P. M.,Sternbell, S.,Tansey, C. W.
, p. 824 - 828 (2007/10/02)
The magnitude of the 4J proton-proton coupling constant across the fragment CH3-C-C-H (a probe of the bond order between the central sp2-sp2 hybridized carbon atoms) has been found to be essentially independent of substitution on a toluene fragment and the size of the ring containing the ortho-allylic fragment.The coupling constant is sensitive to direct substitution on the ortho-allilyc fragment, especially where the substituent is placed α to methyl group.KEY WORDS - 4J proton-proton coupling constant ortho-benzylic coupling constant ring size dependence substituent dependence
