Xn:Harmful;
100-52-7Relevant articles and documents
Synthesis of zeolite@metal-organic framework core-shell particles as bifunctional catalysts
Zhu, Guanghui,Graver, Richard,Emdadi, Laleh,Liu, Baoyu,Choi, Kyu Yong,Liu, Dongxia
, p. 30673 - 30676 (2014)
A zeolite@metal-organic framework (ZSM-5@UiO-66) core-shell composite has been synthesized for the first time by solvothermal growth of UiO-66 on the surface of ZSM-5 particles. The acidity from ZSM-5 and the basicity from the amine groups in UiO-66 obtai
Aerobic oxidation of benzyl alcohol in methanol solutions over Au nanoparticles: Mg(OH)2 vs MgO as the support
Estrada, Miguel,Costa, Vinícius V.,Beloshapkin, Sergey,Fuentes, Sergio,Stoyanov, Evgenii,Gusevskaya, Elena V.,Simakov, Andrey
, p. 96 - 103 (2014)
Magnesium oxide and magnesium hydroxide materials containing supported gold nanoparticles (NPs), Au/Mg(OH)2 and Au/MgO, were prepared from the commercial MgO through the deposition-precipitation (DP) method and characterized by XRD, XPS, HRTEM, FTIR spectroscopy and N2 adsorption techniques. It was found that the starting MgO support was fully transformed into the Mg(OH)2 phase during the DP procedure. A nearly complete dehydration of the magnesium hydroxide and formation of Au/MgO was achieved through the reductive treatment at 500 C, whereas the treatment at 350 C still resulted in the Au/Mg(OH)2 material. The FTIR analysis showed a much higher ability of the Au/MgO surface to adsorb both benzyl alcohol and benzaldehyde (ca. 10 and 3 times, respectively), as compared to Au/Mg(OH) 2. Probably for this reason, the Au/MgO catalyst exhibited ca. 50% higher catalytic activity in the aerobic oxidation/oxidative methoxylation of benzyl alcohol in the methanol solutions with respect to the amount of surface gold atoms as compared to the Au/Mg(OH)2 catalyst, in spite of a larger size of the Au NPs. In addition, the thermal treatment of the catalyst at 500 C to dehydrate the support allowed to suppress the undesired side reaction between benzyl alcohol and primarily formed benzaldehyde to give benzyl benzoate.
A versatile metal-organic framework for carbon dioxide capture and cooperative catalysis
Park, Jinhee,Li, Jian-Rong,Chen, Ying-Pin,Yu, Jiamei,Yakovenko, Andrey A.,Wang, Zhiyong U.,Sun, Lin-Bing,Balbuena, Perla B.,Zhou, Hong-Cai
, p. 9995 - 9997 (2012)
A multi-functional MOF PCN-124 was constructed from Cu paddlewheel motifs and a judiciously designed novel ligand bearing carboxylate, pyridine, and amide groups. PCN-124 exhibits selective adsorption of CO2 over CH 4 and excellent catalytic activity in a tandem one-pot deacetalization-Knoevenagel condensation reaction as a cooperative catalyst. The Royal Society of Chemistry 2012.
Linear free-energy relationships in chromium(VI) oxidation of substituted benzylamines in nonaqueous media
Thirumoorthi,Bhuvaneshwari,Elango
, p. 362 - 369 (2007)
The kinetics of oxidation of 11 para- and meta-substituted benzylamines by imidazolium fluorochromate (IFC) in different organic solvent media has been investigated in the presence of p-toluenesulfonic acid (TsOH). The reaction was run under pseudo-first-
Immobilized V-MIL-101 on modified Fe3O4 nanoparticles as heterogeneous catalyst for epoxidation of allyl alcohols and alkenes
Farzaneh, Faezeh,Sadeghi, Yasaman
, p. 275 - 281 (2015)
As a new heterogeneous catalyst, Fe3O4 nanoparticles were prepared and modified with sodium silicate and (3-aminopropyl) trimethoxysilane (APTMS) followed by complexation with V-MIL-101 and designated as Fe3O4@SiO2@APTMS@VMIL-101. It was characterized using FTIR, TEM, and VSM techniques. The Fe3O4@SiO2@APTMS@VMIL-101 was found to successfully catalyze the epoxidation of allyl alcohols and alkenes with tert-butylhydroperoxide (TBHP) in moderate to high yields. The epoxidation of trans-stilbene, norbornen, cyclooctene, geraniol, trans-2-hexene-1ol and 1-octene-3-ol with 100% selectivity is promising. Investigation of the stability and reusability of Fe3O4@SiO2@APTMS@V-MIL-101 revealed the heterogeneity character of the catalyst with no desorption during the course of epoxidation reactions. High yields, clean reactions, ease of catalyst separation and recyclability of the solid catalyst are some advantages of this method.
Can Contemporary Density Functional Theory Predict Energy Spans in Molecular Catalysis Accurately Enough to Be Applicable for in Silico Catalyst Design? A Computational/Experimental Case Study for the Ruthenium-Catalyzed Hydrogenation of Olefins
Rohmann, Kai,H?lscher, Markus,Leitner, Walter
, p. 433 - 443 (2016)
The catalytic hydrogenation of cyclohexene and 1-methylcyclohexene is investigated experimentally and by means of density functional theory (DFT) computations using novel ruthenium XantphosPh (4,5-bis(diphenylphosphino)-9,9-dimethylxanthene) and XantphosCy (4,5-bis(dicyclohexylphosphino)-9,9-dimethylxanthene) precatalysts [Ru(XantphosPh)(PhCO2)(Cl)] (1) and [Ru(XantphosCy)(PhCO2)(Cl)] (2), the synthesis, characterization, and crystal structures of which are reported. The intention of this work is to (i) understand the reaction mechanisms on the microscopic level and (ii) compare experimentally observed activation barriers with computed barriers. The Gibbs free activation energy ΔG? was obtained experimentally with precatalyst 1 from Eyring plots for the hydrogenation of cyclohexene (ΔG? = 17.2 ± 1.0 kcal/mol) and 1-methylcyclohexene (ΔG? = 18.8 ± 2.4 kcal/mol), while the Gibbs free activation energy ΔG? for the hydrogenation of cyclohexene with precatalyst 2 was determined to be 21.1 ± 2.3 kcal/mol. Plausible activation pathways and catalytic cycles were computed in the gas phase (M06-L/def2-SVP). A variety of popular density functionals (ωB97X-D, LC-ωPBE, CAM-B3LYP, B3LYP, B97-D3BJ, B3LYP-D3, BP86-D3, PBE0-D3, M06-L, MN12-L) were used to reoptimize the turnover determining states in the solvent phase (DF/def2-TZVP; IEF-PCM and/or SMD) to investigate how well the experimentally obtained activation barriers can be reproduced by the calculations. The density functionals B97-D3BJ, MN12-L, M06-L, B3LYP-D3, and CAM-B3LYP reproduce the experimentally observed activation barriers for both olefins very well with very small (0.1 kcal/mol) to moderate (3.0 kcal/mol) mean deviations from the experimental values indicating for the field of hydrogenation catalysis most of these functionals to be useful for in silico catalyst design prior to experimental work.
Selective benzylic oxidation of alkylaromatics over Cu/SBA-15 catalysts under solvent-free conditions
Neeli, Chinna Krishna Prasad,Narani, Anand,Marella, Ravi Kumar,Rama Rao, Kamaraju Seetha,Burri, David Raju
, p. 5 - 9 (2013)
With the purpose of benzylic oxidation of alkylaromatics into corresponding ketones selectively under solvent-free conditions, cheap, simple and versatile Cu/SBA-15 catalyst system with the Cu loading of 5, 10, 15 and 20% has been prepared by impregnating SBA-15 support. Among Cu/SBA-15 catalysts, 10%Cu/SBA-15 exhibited superior activity and selectivity.
Synthesis, structural characterization and application of a 2D coordination polymer of Mn-terephthalate as a heterogeneous catalyst for olefin oxidation
Bagherzadeh, Mojtaba,Ashouri, Fatemeh,Crossed D Signakovi?, Marijana
, p. 167 - 173 (2014)
A metal-organic coordination polymer of [Mn3(1,4- benzenedicarboxylate)3(DMF)4] ([Mn3(BDC) 3(DMF)4]n) was synthesized and characterized by IR spectra, elemental analysis (CHN), thermal gravimetric analysis (TGA) and single crystal X-ray diffraction analysis. The structure of [Mn 3(BDC)3(DMF)4]n is a 2D-periodic framework based on Mn(II)-terephthalate secondary building units (SBUs). The catalytic oxidation of various olefins was effectively carried out with [Mn 3(BDC)3(DMF)4]n. Moreover, the influence of key reaction parameters, including the solvents, reaction temperatures and nature of oxidant were studied. The optimized conditions were achieved by TBHP as the efficient oxidant in 1,2-dichloroethane solvent at 75 C. Finally, this catalyst was used for four cycles efficiently without a significant loss of yield.
A bifunctional approach towards the mild oxidation of organic halides: 2-dimethylamino-N,N-dimethylaniline N-oxide
Chandrasekhar, Sosale,Sridhar, Malayalam
, p. 5423 - 5425 (2000)
The titled reagent incorporates an oxygen-centred nucleophile and a basic moiety - in a suitably mutual orientation - in the same molecule. It oxidises various primary benzylic bromides to the corresponding aromatic aldehydes under relatively mild conditions (MeCN/rt-50°C/6-24 h) in high yields (83-97%), and is thus a useful alternative to the Kornblum procedure. (C) 2000 Elsevier Science Ltd.
Weakly distorted 8-quinolinolato iron(III) complexes as effective catalysts for oxygenation of organic compounds by hydrogen peroxide
Wang, Yongjun,Wen, Xu,Rong, Chunying,Tang, Senpei,Wu, Wenfeng,Zhang, Chao,Liu, Yachun,Fu, Zaihui
, p. 103 - 109 (2016)
This paper first discloses that two heteroleptic 8-quinolinolato iron(III) complexes (Qa1Qb2FeIII, Qa2Qb1FeIII) could be synthesized conveniently via the coordination of FeCl2·6H2O with 2 equivalents of 5,7-dichloro-8-hydroxyquinoline (Qb) or 5-chloro-8-hydroxyquinoline (Qa) under N2 and then 1 equivalent of Qa or Qb under air. In comparison with the two homoleptic counterparts (Qa3FeIII and Qb3FeIII), the proposed heteroleptic Q3FeIII complexes possessed similar coordination features to the Qb3FeIII one but showed similar catalysis performances to the Qa3FeIII one in the oxygenation of cyclohexane to cyclohexanol and cyclohexanone by hydrogen peroxide (H2O2) in acetonitrile. More importantly, both heteroleptic Q3FeIII complexes showed a better accelerating effect on this reaction and provided a slightly higher conversion than the Qa3FeIII and especially Qb3FeIII ones. Furthermore, this predominance in catalytic activity was more strikingly apparent upon both-catalyzed oxygenations of benzene, toluene, ethylbenzene or thioanisole by H2O2. This should be due to a structurally distorted effect of the heteroleptic Q3FeIII complexes that is induced by the different in ligand environment, as supported by DFT B3LYP/6-311G (d) calculation. Based the present reaction and UV-vis spectral characterization results, a free radical mechanism for the present catalysis system was proposed.
