1436-34-6Relevant academic research and scientific papers
Colloidal gold nanoparticles: An unexpected catalytic activity in aqueous phase with dioxygen
Salari, Hadi,Robatjazi, Hossein,Hormozi-Nezhad, Mohammad Reza,Padervand, Mohsen,Gholami, Mohammad Reza
, p. 1219 - 1222 (2014)
Selective oxidations of alkenes were investigated using molecular oxygen in aqueous solution under mild conditions. Colloidal gold nanoparticles are particularly versatile catalysts for oxidation reaction with exceptionally high efficiency and significant selectivity. Gold nanorods (Au NRs) exhibited a slightly enhanced activity compare to gold nanospheres.
Alkoxysilylation of Ti-MWW lamellar precursors into interlayer pore-expanded titanosilicates
Wang, Lingling,Wang, Yong,Liu, Yueming,Wu, Haihong,Li, Xiaohong,He, Mingyuan,Wu, Peng
, p. 8594 - 8602 (2009)
Silylation of Ti-MWW lamellar precursor and subsequent calcination constructed an interlayer expanded structure, leading to novel titanosilicates with large pores. The silylating agents suitable for pore expansion were diethoxydimethylsilane, trimethylethoxysilane and triethoxymethylsilane containing methyl groups, which inhibited the intermolecular condensation of silanes effectively. In contrast to well-known 3D Ti-MWW with only medium pores of 10-membered rings, the silylation led to new crystalline structures with more open pores by ca. 2.5 A, as evidenced by the shift of layer-related diffractions to the lower-angle region in XRD patterns and the enlarged interlayer pores in HRTEM images. The interlayer expanded Ti-MWW was prepared readily from the corresponding hydrothermally synthesized precursors with a wide range of Ti contents (Si/Ti = 20-100). In addition, the pore expansion by silylation was realized under mild acid conditions with 0.1 M HNO3. The interlayer expanded Ti-MWW exhibited 3-7 times higher turnover number than 3D Ti-MWW in the oxidation of cyclohexene with H2O2. The Royal Society of Chemistry 2009.
Catalytic olefin epoxidation over cobalt(ii)-containing mesoporous silica by molecular oxygen in dimethylformamide medium
Bhunia, Susmita,Jana, Sreyashi,Saha, Debraj,Dutta, Buddhadeb,Koner, Subratanath
, p. 1820 - 1828 (2014)
A cobalt(ii) Schiff base complex has been immobilized onto the surface of Si-MCM-41 to prepare a new catalyst. The amine group-containing organic moiety 3-aminopropyl-triethoxysilane had first been anchored on the surface of Si-MCM-41 via a silicon alkoxide route. Upon condensation with salicylaldehyde, the amine group affords a bidentate Schiff-base moiety in the mesoporous matrix, which is subsequently used for anchoring of cobalt(ii) centers. The prepared catalyst has been characterized by UV-vis, infrared (IR), EPR spectroscopic and small angle X-ray diffraction (XRD) analyses, and N2 sorption studies. The catalytic activity was tested in epoxidation reactions of olefinic compounds, including styrene and allyl alcohol, with molecular oxygen at atmospheric pressure in dimethylformamide medium in the absence of additional sacrificial reductant. The reactions seemed to proceed through a radical formation mechanism. The immobilized catalyst showed good activity and epoxide selectivity in the alkene epoxidation. Notably, the catalyst can be recovered and reused without any loss of activity. This journal is the Partner Organisations 2014.
Fast catalytic epoxidation with H2O2 and [γ-SiW10O36(PhPO)2]4- in ionic liquids under microwave irradiation
Berardi, Serena,Bonchio, Marcella,Carraro, Mauro,Conte, Valeria,Sartorel, Andrea,Scorrano, Gianfranco
, p. 8954 - 8957 (2007)
(Figure Presented) Olefin epoxidation by [γ-SiW10O 36(PhPO)2]4- and H2O2 occurs in hydrophobic ionic liquids (ILs), with yields and selectivity up to >99%. The catalytic IL phase is recyclable. Under MW irradiation the reaction occurs with up to 200 turnovers per minute. Simultaneous cooling is instrumental for quantitative H2O2 conversion.
Synthesis, spectroscopic characterization, thermal studies, catalytic epoxidation and biological activity of chromium and molybdenum hexacarbonyl bound to a novel N2O2 Schiff base
Abdel Aziz, Ayman A.
, p. 77 - 85 (2010)
Complexes of M(CO)6 (M = Cr and Mo) with novel Schiff base N,N′-bis(salicylidene)4,5-dichloro-1,2-phenylenediamine (H2L) were prepared in benzene in two different conditions: (i) under reduced pressure resulting the dicarbonyl precursors [Cr(CO)2(H2L)] and [Mo(CO)2(L)] and (ii) in air resulting the oxo complex [Cr(O)(L)] and the dioxo complex [Mo(O)2(L)]. The complexes were characterized by elemental analysis, IR, 1H NMR, mass spectrometry, and magnetic measurement. Thermal behaviors of the complexes were also studied by using thermogravimetric analysis (TGA). The catalytic activity of the novel complexes in the epoxidation of cyclooctene, cyclohexene, 1-octene and 1-hexene with tert-butyl-hydroperoxide (TBHP) in methylene chloride was investigated. The antimicrobial activities of the ligand and their complexes have been screened against various strains of bacteria and fungi and the results have been compared with some known antibiotics.
Enhancement of alkene epoxidation activity of titanosilicates by gas-phase ammonia modification
Zhang, Liyan,Xu, Le,Sun, Jingjing,Jiang, Jingang,Liu, Yueming,Wu, Haihong,Wu, Peng
, p. 2205 - 2211,7 (2012)
Novel ammonia-treated titanosilicates have been prepared by heating the samples of Ti-MWW, TS-1 and Ti-Beta under pure ammonia gas flow at 673 K for a period of time. The ammonia modification improved their catalytic performance in liquid-phase oxidations. Especially, the catalytic activities of ammonified Ti-MWW, N-Ti-MWW, were enhanced greatly in the epoxidation of 1-hexene with H2O2. The reason that the ammonia treatment played such an important role in post-modification of titanosilicate was investigated in details. In comparison to the parent Ti-MWW catalyst, N-Ti-MMW was more robust and produced less coke in oxidation reactions.
Nanoparticulate tungsten oxide for catalytic epoxidations
Hammond, Ceri,Straus, Julian,Righettoni, Marco,Pratsinis, Sotiris E.,Hermans, Ive
, p. 321 - 327 (2013)
A combination of spectroscopic and catalytic investigations led to the surprising conclusion that not isolated WVI species but WO 3 oxide is the most active and stable phase for olefin epoxidation with H2O2. Opt
A recyclable hybrid manganese(III) porphyrin magnetic catalyst for selective olefin epoxidation using molecular oxygen
Dias, Lucas D.,Carrilho, Rui M.B.,Henriques, César A.,Piccirillo, Giusi,Fernandes, Auguste,Rossi, Liane M.,Filipa Ribeiro,Calvete, Mário J.F.,Pereira, Mariette M.
, p. 331 - 341 (2018)
The synthesis and characterization of a hybrid Mn(III)-porphyrin magnetic nanocomposite is described. Moreover, a sustainable methodology for epoxidation of olefins is reported, using O2 as a green oxidant and the magnetic nanoparticle as a rec
Manganese(III) Tetraphenylporphyrin Encapsulated by Ion-Modified Hexagonal Mesoporous Silica With Unexpected Enhanced Epoxidation Selectivity
Zhang, Weijie,Jiang, Pingping,Wang, Ying,Zhang, Jian,Zhang, Pingbo
, p. 1765 - 1772 (2016)
Tetraphenylporphyrin manganese (III) chloride (Mn-TPP) was encapsulated into hexagonal mesoporous silica (HMS) modified by different Lewis acid ions Al, Ti, Zr, and W, which have been tested for selective oxidation of unsaturated olefins and more challeng
Highly effective peroxidic epoxidation of olefins using hexathiocyanatorhenate(IV) as catalyst and bicarbonate as co-catalyst
Dinda, Subhajit,Roy Chowdhury, Sujoy,Abdul Malik,Bhattacharyya, Ramgopal
, p. 339 - 341 (2005)
In the presence of bicarbonate as co-catalyst hexathiocyanatorhenate(IV) functions as an extremely effective catalyst in the epoxidation of olefins using aqueous hydrogen peroxide as the terminal oxidant.
