287-25-2Relevant academic research and scientific papers
A CLASSIFICATION OF THE PHOTOCHEMICAL ELECTROCYCLIC REACTIONS OF HETEROATOM CONJUGATED SYSTEMS
Kikuchi, O.
, p. 859 - 862 (1981)
Photochemical electrocyclic reaction mechanism of a variety of heteroatom conjugated systems has been elucidated by a unique concept.The proposed classification of the reaction, which is based upon the number and types of electrons involved in the reaction centers, takes into account the participation of the lone-pair electrons and gives the correct description of the electron behavior during the electrocyclic reaction process.
Titania Morphology-Dependent Gold-Titania Interaction, Structure, and Catalytic Performance of Gold/Titania Catalysts
Chen, Shilong,Zhang, Bingsen,Su, Dangsheng,Huang, Weixin
, p. 3290 - 3298 (2015/10/28)
Employing anatase TiO2 nanocrystals with predominantly {001} facets, anatase TiO2 nanocrystals with predominantly {100} facets, and TiO2 P25 with predominantly {101} facets as supports, we have comprehensively studied the morphology effect of TiO2 on the Au-TiO2 interaction, structure, and catalytic performance of Au/TiO2 catalysts in C3H6 epoxidation with H2 and O2, C3H6 oxidation with O2, and H2 oxidation. A strong morphology-dependent interplay between the Au-TiO2 interaction and the catalyst structure was observed. Only Au nanoparticles were present in the Au/TiO2 catalysts and the Auδ- species was the largest in Au/TiO2{001} due to the creation of surface O vacancies of TiO2{001} upon Au loading, whereas the fraction of Auδ+ species was largest in Au/TiO2{100} due to the preserved surface stoichiometry of TiO2{100} upon Au loading. In H2 oxidation, Au/TiO2{100} with the largest fraction of Auδ+ species was the most active but least selective toward H2O2, whereas Au/TiO2{001} with the largest fraction of Auδ- species was the most selective toward H2O2. In C3H6 oxidation with O2, tiny C3H6 conversions with the formation of partial oxidation products were observed at low temperatures, whereas C3H6 combustion occurred at high temperatures. In C3H6 epoxidation with O2 and H2, the ensemble consisting of closely connected Auδ- and Ti4+ on anatase TiO2{001} and {101} facets with weak adsorption ability was the active structure and the Au/TiO2{001} catalyst containing the largest amount of this ensemble was the most active. These results demonstrated morphological engineering of oxides as an effective strategy to optimize the catalytic performance and understand the fundamentals of catalysis involving oxides. Titania mania: The Au-TiO2 interaction, structure and catalytic performance of Au/TiO2 catalysts in C3H6 epoxidation with H2 and O2, C3H6 oxidation, and H2 oxidation strongly depend on the TiO2 morphology. In the epoxidation, the ensemble of closely connected Auδ- and Ti4+ on anatase TiO2{001} and {101} facets with weak adsorption ability is the active structure and the Au/TiO2{001} catalyst containing the largest amount of the Auδ--Ti4+ ensemble is the most active.
Gas-phase epoxidation of propylene over iron-containing catalysts: The effect of iron incorporation in the support matrix
Horvath, Blazej,Sustek, Martin,Vavra, Ivo,Micusik, Matej,Gal, Miroslav,Hronec, Milan
, p. 2664 - 2673 (2014/07/22)
The gas-phase epoxidation of propylene using iron as a catalytically active metal has been studied. The XRD-amorphous silica nanopowder was found to host active as well as redox-silent iron species, using nitrous oxide as an oxidizing agent. The presence of iron oxide nanoparticles was proven in the most active catalysts, indicating that the epoxidation proceeds over nanoparticles rather than over isolated iron atoms. A combination of XPS, TEM and voltammetric techniques elucidated the mechanism of the formation of catalytically active forms of iron oxide, distinguishing selective forms from unselective and inactive ones in the epoxidation reaction. Transition response experiments showed a good correlation between epoxidation activity, N2O decomposition and electrochemical specification of iron oxides.
Syntheses and Reactions of 3-Phenyloxete and the Parent Unsubstituted Oxete
Friedrich, Louis E.,Lam, Patrick Yuk-Sun
, p. 306 - 311 (2007/10/02)
The elimination of p-toluenesulfonic acid and o-nitrophenylselenilic acid from substituted oxetanes gives 3-phenyloxete (6) and oxete (9), respectively. 3-Phenyloxete (6) undergoes the expected chemistry as well as a facile addition of triplet oxygen to g
