共查询到14条相似文献,搜索用时 0 毫秒
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合成了2,2’-(氧二亚甲基)双苯并咪唑及其Ni(Ⅱ)和La(Ⅲ)的配合物,采用元素分析、红外光谱、紫外光谱和摩尔电导率等进行表征,研究了它们的固体荧光性质,发现它们都是良好的荧光物质。 相似文献
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Steve Lien‐Chung Hsu Keng‐Chuan Chang Yuan‐Pin Huang Shih‐Jung Tsai 《应用聚合物科学杂志》2003,88(10):2388-2391
A poly(imide benzoxazole) was prepared directly from trimellitic anhydride chloride and 2,2‐bis(3‐amino‐4‐hydroxyphenyl)hexafluoropropane (BisAPAF) monomers in a two‐step method. In the first step, a poly(hydroxyamide amic acid) precursor was synthesized by the low‐temperature solution polymerization in an organic solvent. Subsequently, thermal cyclodehydration of the poly(hydroxyamide amic acid) precursor at 350°C produced the corresponding poly(imide benzoxazole). The inherent viscosity of the precursor polymer was 0.22 dL/g. The cyclized poly(imide benzoxazole) showed a glass transition temperature (Tg) at 329°C and a 5% weight loss temperature at 530°C in nitrogen and at 525°C in air. The poly(imide benzoxazole) is amorphous as evidenced by the wide‐angle X‐ray diffraction measurement. The structures of the precursor polymer and the fully cyclized polymer were characterized by Fourier transform infrared (FTIR) and proton nuclear magnetic resonance spectroscopy (1H NMR). © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2388–2391, 2003 相似文献
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Guangxing Li Lijuan Chen Jie Bao Tao Li Fuming Mei 《Applied Catalysis A: General》2008,346(1-2):134-139
A green process for the synthesis of methyl N-phenylcarbamate (MPC) by the oxidative carbonylation of aniline was studied. In this process, Co(salen) complexes were successfully encapsulated in zeolite Y by a flexible ligand method. The heterogeneous catalysts were characterized by AAS, BET, IR, TGA, XRD and XPS. The catalytic activities of the encapsulated catalysts and their homogeneous analogues were examined in the oxidative carbonylation of aniline to MPC. Under the conditions of aniline (11 mmol), encapsulated catalyst (0.5 g), KI (0.365 g), CO/O2 ratio 9:1, 4 MPa, 170 °C, 3 h, Co(salophen)(OH)2–Y catalyst shows the highest activity with the conversion of 67.1% and the selectivity of 77.3%. Co(salophen)(OH)2–Y could be recycled at least five times and no significant loss of catalytic activity was observed. 相似文献
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Rice husk ash (RHA), as a source of amorphous silica, was treated with chlorosulfonic acid and sulfonated rice husk ash (RHA-SO3H) as a highly powerful solid acid catalyst was obtained and characterized with a variety of techniques including IR, TGA, SEM, XRD, pH analysis, Hammett acidity function and BET method. This solid acid showed excellent catalytic activity for the protection and deprotection of aldehydes with Ac2O at room temperature under solvent free conditions. The procedure gave the products in excellent yields in very short reaction times and good to high yields. Also this catalyst can be reused for several times without loss of its catalytic activity. 相似文献
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A straightforward approach for the construction of 5H‐benzo[b]‐, carbazolo[2,3‐b]‐ and indolo[2,3‐b]carbazole derivatives has been developed by using copper(II) triflate‐catalyzed heteroannulation. 相似文献
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P. Fabbri S. Mohammad Poor L. Ferrari L. Rovati S. Borsacchi M. Geppi P.P. Lima L.D. Carlos 《Polymer》2014
The rare-earth metal organic chelate [Eu(btfa)3(MeOH)(bpeta)] (btfa, 4,4,4-trifluoro-1-phenyl-1,3-butanedionate; bpeta, 1,2-bis(4-pyridyl)ethane) has been used to dope a plastic optical fibre (POF) prepared by the bulk homopolymerization of hexamethylene diisocyanate (HMDI) catalysed by Tin(II)-2 ethylhexanoate (SnOct), to obtain a plastic optical fibre amplifier (POFA). The Eu3+ chelate, primarily added as luminophore for the amplification of the optical signal, showed an interesting co-catalytic activity in the polymerization of HMDI, that preferentially proceeded towards the formation of the highly stable polyisocyanurate trimer form thanks to its selective driving action, as demonstrated by 13C solid-state NMR. Pumping of the POFA with xenon lamps demonstrated the occurrence of stimulated emission inside the doped fibre. 相似文献
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Luis Gmez-Hortigüela Teresa Blasco Joaquín Prez-Pariente 《Microporous and mesoporous materials》2007,100(1-3):55-62
A new chiral structure directing agent, (S)-(−)-N-benzylpyrrolidine-2-methanol, has been rationally designed, synthesized and successfully used to direct the crystallization of the AFI-type structure in various compositions. AlPO-5, SAPO-5, MgAPO-5, VAPO-5, CoAPO-5 and ZnAPO-5 materials have been obtained and characterized by several physico-chemical techniques. Characterization results demonstrated the incorporation of the different dopants within the microporous network, giving place to materials with potential catalytic properties. 相似文献
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Du Lijun Qin Wei Wang Jingdai Yang Yongrong Wu Wenqing Jiang Binbo 《Polymer International》2011,60(4):584-591
Spherical and well‐dispersed silica/poly[styrene‐co‐(acrylic acid)] (SiO2/PSA) core–shell particles have been synthesized using an improved phase‐inversion process. The resulting particles were successfully used as supports for polyolefin catalysts in the production of polyethylene with broad molecular weight distribution. Through the vapor phase, instead of the liquid phase in the traditional process, a non‐solvent was introduced into a mixture of micrometer‐sized SiO2 and PSA solution. The core–shell structure of the resulting SiO2/PSA microspheres was confirmed using optical microscopy, scanning electron microscopy, Fourier transfer infrared spectrometry, thermogravimetric analysis and measurement of nitrogen adsorption/desorption isotherms. In order to avoid agglomeration of particles and to obtain a good dispersion of the SiO2/PSA core–shell microspheres, the non‐solvent was added slowly. As the concentration of PSA solution increased, the surface morphology of the core–shell particles became looser and more irregular. However, the surface area and the pore volume remained the same under varying PSA concentrations. The SiO2/PSA core‐shell microspheres obtained were used as a catalyst carrier system in which the core supported (n‐BuCp)2ZrCl2 and the shell supported TiCl4. Ethylene/1‐hexene copolymerization results indicated that the zirconocene and titanium‐based Ziegler–Natta catalysts were compatible in the hybrid catalyst, showing high activities. The resulting polyethylene had high molecular weight and broad molecular weight distribution. Copyright © 2010 Society of Chemical Industry 相似文献
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Silica-modified magnetite-polyoxometalates functionalized with sulfamic acid groups as hybrid nanoparticles were prepared by sulfonation of diamine-functionalized propyl group grafted on the magnetic silica-coated Fe3O4 nanoparticles. This heterogeneous nanocatalyst was explored to present high catalytic performance for the synthesis of 3,4-dihydropyrimidinones and tetrahydrobenzo[b]pyrans under mild reaction conditions. The properties of this nanocatalyst were characterized by FT- infrared, energy-dispersive X-ray spectrum, scanning electron microscope, X-ray diffraction, X-ray fluorescence and elemental analysis. Easy separation of the nanocatalyst by using an external magnet, recyclability, non-toxicity, versatility and high stability of the catalyst combined with low reaction times and excellent yields make the present protocol very useful and attractive for the synthesis of the titled products. 相似文献
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Farhad Shirini Manouchehr MamaghaniSeyyed Vahid Atghia 《Catalysis communications》2011,12(12):1088-1094
Sulfonic acid-functionalized ordered nanoporous Na+-montmorillonite (SANM) was used as an efficient catalyst for N-tert-butoxycarbonylation of amines with di-tert-butyl dicarbonate under solvent-free conditions at room temperature. Various aliphatic, aromatic, heterocyclic amines and aminols were protected as their corresponding mono-carbamates in excellent yields and short reaction times. No competitive side reactions such as isocyanate, urea, and N,N-di-Boc formation were observed. The reported method is mild, chemoselective and has the advantages such as heterogeneous catalysis, low cost and the recyclability of the catalyst. 相似文献
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An ionic liquid, 1-butyl-3-methylimidazolium bromide, is used as reaction medium for the synthesis and crystallization of a coordination polymer, (BMIM)2[Cd3(BDC)3Br 2] (1) (BMIM = 1-butyl-3-methylimidazolium, BDC = 1,4-benzenedicarboxylate), which forms an anionic two-dimensional framework with the imidazolium cations located between the layers. This compound is thermally stable up to ca. 340 °C and exhibits blue emission in solid state at room temperature. Other characterizations by IR and UV–visible spectra are also described. 相似文献