106-88-7Relevant articles and documents
Epoxidation of olefins at low temperature using m-chloroperbenzoic acid
Srinivasan,Chandrasekharam,Vani,Chida, A. Seema,Singh
, p. 1853 - 1858 (2002)
Epoxidation of olefins using m-chloroperbenzoic acid in dichloromethane without catalyst at low temperature is described.
Transformation of vinyloxirane on Pt-SiO2 and Pd-SiO2
Bartok, Mihaly,Fasi, Andras,Notheisz, Ferenc
, p. 40 - 47 (1998)
The transformation of vinyloxirane and ethyloxirane were studied on Pt-SiO2 and Pd-SiO2 catalysts at 273 and 301 K in a recirculation reactor, in the presence of hydrogen or deuterium. There are significant differences, not only in reaction rates, but also in reaction routes, depending upon the nature of the metal. The main reaction routes are: deoxygenation and hydrogen or deuterium addition on Pt-SiO2; isomerization and hydrogenolysis on Pd-SiO2. The reaction routes leading to the formation of the individual products are interpreted on the basis of the experimental results. In the case of the hydrogenolysis of oxiranes, Pd was shown to exhibit a special reactivity, unlike earlier observations described in the literature.
Synthesis, crystal structure, and catalytic property of a vanadium(V) complex with mixed ligands
Shen,Zhang,Shao,Lian,Liu
, p. 372 - 375 (2015)
With a tridentate hydrazone ligand N′-(3-bromo-2-hydroxybenzylidene)-2-methylbenzohy-drazide (H2L) and a bidentate ligand benzohydroxamic acid (HL′) with VO(Acac)2, a mononuclear vanadium(V) complex was prepared and characterized by elemental analysis, IR spectroscopy and X-ray structure determination (CIF file CCDC no. 1029909). The complex crystallizes in the monoclinic space group C2/c with unit cell dimensions a = 27.870(2), b = 11.4893(5), c = 18.467(2) ?, β = 131.444(1)°, V = 4432.6(6) ?3, Z = 8, R 1 = 0.0350, and wR 2 = 0.0749. Single crystal X-ray diffraction analysis reveals that the V atom is coordinated by the phenolate O, imino N and enolate O atoms of the hydrazone ligand, and the carbonyl O and hydroxy O atoms of benzohydroxamate ligand, and one oxo O group, in an octahedral coordination. Catalytic oxidation of the complex on some olefins was performed.
Role of Recrystallization in Alkaline Treatment on the Catalytic Activity of 1-Butene Epoxidation
Zuo, Yi,Yang, Liqian,Jiang, Xiao,Ma, Mengtong,Wang, Yanli,Liu, Min,Song, Chunshan,Guo, Xinwen
, p. 6196 - 6204 (2020)
Two alkylol amines, which were ethanolamine (EOA) and triethanolamine (TEOA), were used to posttreat nanosized titanium silicalite-1 (TS-1) to improve its catalytic activity for 1-butene epoxidation. Comparative studies were conducted to clarify the influences of the EOA and TEOA concentrations on the physicochemical properties through detailed characterization. EOA treatment can dissolve the framework Si, [SiO4], on the external surface of TS-1, generating some macropores. TEOA serves as structure-directing agent to form MFI topology other than the dissolution of [SiO4], and promotes the recrystallization of [SiO4], forming new TS-1 particles over the external surface. The two treatments can both improve the catalytic activity of 1-butene epoxidation, but the samples treated with TEOA exhibit better catalytic stability. This can be attributed to the characteristic recrystallization of [SiO4] in the case of TEOA treatment, stabilizing the structure of TS-1 and maintaining more framework Ti and intercrystal space.
Characterization and evaluation of Ag-Pt/SiO2 catalysts prepared by electroless deposition
Schaal, Melanie T.,Pickerell, Anna C.,Williams, Christopher T.,Monnier, John R.
, p. 131 - 143 (2008)
A series of Ag-Pt/SiO2 catalysts have been prepared by the electroless deposition of Ag onto a Pt/SiO2 catalyst. Results indicate that Ag deposition does not readily occur on the SiO2 support, but is essentially restricted
Deboronation-assisted construction of defective Ti(OSi)3OH species in MWW-type titanosilicate and their enhanced catalytic performance
Chen, Zhen,He, Mingyuan,Liu, Haoxin,Liu, Wei,Liu, Yueming,Tang, Zhimou,Wang, Rui,Wu, Haihong,Yu, Yunkai
, p. 2905 - 2915 (2020)
A thorough investigation of the nature of the Ti species in the boron-containing Ti-MWW zeolite has been carried out. It was found that the inactive extra-framework TiO6 species can cover up the zeolite Lewis-acid property through the weak atomic binding forces between the Ti(iv) atom and O atom (TiO6 species). The nitric acid treatment could remove these TiO6 species easily from the as-synthesized Ti-MWW(P), followed by exposure of the zeolite Lewis acidity. Importantly, the formation of new Ti(OSi)3OH species with a strong Lewis-acid strength, is facilitated in the modification process. Thereby, the modified Ti-MWW zeolite has an improved catalytic activity in alkene epoxidation reactions. The removal of framework B(iv) species around the TiO4 species is an essential step because it can accelerate the transformation of perfect Ti(OSi)4 species to the defective Ti(OSi)3OH species in zeolites. Moreover, the strategy to construct Ti(OSi)3OH species was also applied successfully in boron-containing Ti-MCM-56 zeolites. Considering active species environment can be modulated effectively with the removal of framework tetra-coordinate boron, this strategy could also be beneficial for the preparation of other high-performance titanosilicates.
Synthesis, crystal structure and catalytic property of a dinuclear cobalt(III) complex derived from 2-ethyl-2-{[1-(2-hydroxy-5-methylphenyl)methylidene]amino}propane-1,3-diol
Qiu, Xiao-Yang
, p. 182 - 186 (2018)
With a tetradentate Schiff base ligand 2-ethyl-2-{[1-(2-hydroxy-5-methylphenyl)methylidene]amino}propane-1,3-diol (H3L) with cobalt nitrate and ammonium thiocyanate, a dinuclear cobalt(III) complex was prepared and characterized by elemental analysis, IR spectroscopy and X-ray structure determination. The complex crystallizes in the monoclinic space group P21/n with unit cell dimensions a = 17.682(2) ?, b = 22.652(2) ?, c = 18.617(2) ?, β = 99.546(2)°, V = 7,353.5(12) ?3, Z = 4, R1 = 0.0956, and wR2 = 0.2027. Single crystal X-ray diffraction analysis reveals that the asymmetric unit of the compound contains two dinuclear cobalt(III) complex molecules, three methanol molecules and one water molecule of crystallization. The Co???Co distances in the dinuclear cobalt(III) complex molecules are about 2.97 ?. The Co atoms are in octahedral coordination. The complex has effective property on the oxidation of various aliphatic and aromatic olefins.
Catalytic Asymmetric Cyclization of Some Bromohydrins with Chiral Cobalt Complex
Takeichi, Tsutomu,Takakura, Teruo,Ishimori, Michihiro,Tsuruta, Teiji
, p. 603 - 605 (1988)
Asymmetric cyclization of a variety of bromohydrins with base was examined in the presence of an optically active cobalt(salen) type complex.Optically active oxiranes of modest optical purities were obtained. erythro-3-Bromo-2-butanol and threo-3-bromo-2-butanol were cyclized similarly, and only trans-2,3-dimethyloxirane and cis-2,3-dimethyloxirane were obtained, respectively, indicating that the cyclization of bromohydrin proceeds by complete SN2 type reaction.
Structural and dynamical aspects of alkylammonium salts of a silicodecatungstate as heterogeneous epoxidation catalysts
Uchida, Sayaka,Kamata, Keigo,Ogasawara, Yoshiyuki,Fujita, Megumi,Mizuno, Noritaka
, p. 9979 - 9983 (2012)
The structural and dynamical aspects of alkylammonium salts of a silicodecatungstate [(CH3)4N]4[γ-SiW 10O34(H2O)2] [C1], [(n-C 3H7)4N]4[γ-SiW 10O34(H2O)2] [C3], [(n-C 4H9)4N]4[γ-SiW 10O34(H2O)2] [C4], and [(n-C 5H11)4N]4[γ-SiW 10O34(H2O)2] [C5] were investigated. The results of sorption isotherms, XRD analyses, and solid-state NMR spectroscopy show that facile sorption of solvent molecules, flexibility of structures, and high mobility of alkylammonium cations are crucial to the uniform distribution of reactant and oxidant molecules throughout the bulk solid, which are related to the high catalytic activities for epoxidation of alkenes.
Liquid- and vapor-phase hydrogenation of 1-epoxy-3-butene using self-assembled monolayer coated palladium and platinum catalysts
Kahsar, Karl R.,Schwartz, Daniel K.,Medlin, J. Will
, p. 102 - 106 (2012)
Alkanethiol self-assembled monolayers (SAMs) have recently been shown to be effective catalyst modifiers for increasing the selectivity of the hydrogenation of 1-epoxy-3-butene (EpB) to 1-epoxybutane in the gas phase. In the results reported here, we demonstrate that SAM coatings can similarly be applied to other supported metals (Pt) and in liquid-phase reaction environments. Coating a Pt/Al2O3 catalyst with n-octadecanethiol resulted in a large improvement in selectivity during vapor-phase EpB hydrogenation, similar to that observed for supported Pd. The liquid phase hydrogenation of EpB using SAM-coated catalysts showed similar selectivity trends in some cases, but interactions of the solvent with the SAM were also important in controlling selectivity. In particular, using a heptane solvent, epoxybutane selectivity increased from 36% with an uncoated Pd/Al 2O3 catalyst to 74% with a thioglycerol SAM-coated catalyst. SAM quality was shown to have a strong impact on the rate of reaction but little effect on selectivity. The results generally indicated that selectivity modification with thiol SAMs is extendable to other supported metals and a variety of reaction environments.
