排序方式: 共有117条查询结果,搜索用时 219 毫秒
81.
Derya Baran Felix M. Pasker Stephan Le Blanc Gregor Schnakenburg Tayebeh Ameri Sigurd Höger Christoph J. Brabec 《Journal of polymer science. Part A, Polymer chemistry》2013,51(4):987-992
A new donor‐acceptor copolymer consisting of triazoloquinoxaline and 9,9‐dialkylfluorene units on the main chain has been synthesized, characterized and evaluated as donor material in bulk heterojunction solar cells using PC61BM as an acceptor. The resulting polymer PTQF showed good thermal stability and solubility in common organic solvents. Cyclic Voltammetry measurements showed that the PTQF has HOMO–LUMO energy levels of ?5.13 and ?3.62 eV, respectively. DFT calculations revealed that the HOMO is delocalized all over the thiophene and fluorene units and the LUMO is localized mainly on the triazole and pyrazine units. PTQF absorbs broadly in the visible region and exhibits a bandgap of 1.4 eV. Photovoltaic devices exhibited 1.7% efficiency for 1:2 PTQF:PC61BM blend ratio using Ca/Ag electrodes. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013 相似文献
82.
Hojatollah Khabazzadeh Esmat Tavakolinejad Kermani Tayebeh Jazinizadeh 《Arabian Journal of Chemistry》2012,5(4):485-488
A simple ammonium salt of sulfuric acid in molten state was used as a cheap and mild acidic ionic liquid for efficient synthesis of 3,4-dihydropyrimidin-2(1H)-ones in good to excellent yields. 相似文献
83.
Heteroepitaxial growth of III‐Sb nanowires allows for the formation of various interesting complex structures and enables the combination of their remarkable properties. In this Letter, we investigate the heteroepitaxial growth of Au‐seeded InSb and GaSb nanowires using metalorganic vapor phase epitaxy. We demonstrate successful single and double axial InSb–GaSb heterostructures in both directions. The formation properties of the grown nanowires including the compositional change of the particle and the interface sharpness are further discussed. In addition, the decomposition of InSb and GaSb segments and their side facet evolution are explained.
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85.
Tayebeh Besharati-Seidani Ali Keivanloo Babak Kaboudin Akihiro Yoshida Tsutomu Yokomatsu 《Tetrahedron》2018,74(19):2350-2358
The regioselective synthesis of 1-alkyl-2-aryl-3-acyl pyrrolo[2,3-b]quinoxalines through palladium-catalyzed Heck coupling reaction/heteroannulation was reported. The reaction of N-alkyl/benzyl-3-chloroquinoxaline-2-amines with chalcones catalyzed by Pd(OAc)2 in the presence of KOtBu, as the base, in DMSO afforded the desired products in good-to-high yields. The MIC and MBC determinations revealed that these compounds could be used in the future research works for the development of antibiotics. 相似文献
86.
Kobra Ghobadi Hamid R. Zare Hossein Khoshro Alireza Gorji Abbas A. Jafari 《Comptes Rendus Chimie》2018,21(1):14-18
A Ni(II) complex, [NiII(Me4-NO2Bzo[15]tetraeneN4)], was used for electrocatalytic reduction of CO2 in acetonitrile solvent. Then, the reduced form of CO2 (CO2?) was used for selective carboxylation of phenylacetylene to produce cinnamic acid at room temperature. The potential of the process is significantly less negative in comparison with those reported earlier. Using sacrificial magnesium electrode as anode, controlled potential coulometry was carried out in an undivided glass cell. The spectral characterizations of FTIR, 1H NMR, and 13C NMR demonstrated that cinnamic acid was the main product of the electrolysis. With respect to other catalysts, which have been previously reported in the literature, application of the Ni(II) complex in carboxylation of unsaturated compounds has three advantages: (1) the selectivity in the production of cinnamic acid; (2) more increase in the reduction current indicating that the carboxylation of phenylacetylene is fast; and (3) the potential shift of electrocatalytic reduction of CO2 to less negative values showing that the Ni(II) complex has an excellent electrocatalytic activity for CO2 reduction. According to the voltammetric and coulometric results, an EC′CCC′C mechanism was proposed for the electrocatalytic synthesis of cinnamic acid. 相似文献
87.
Mehdi Amirnasr Amir H. Mahmoudkhani Alireza Gorji Saeed Dehghanpour Hamid Reza Bijanzadeh 《Polyhedron》2002,21(27-28)
A series of complexes of the type M(Phca2en)X2, where Phca2en=N,N′-bis(β-phenyl-cinnamaldehyde)-1,2-diiminoethane, M(II)=Co, Ni or Zn and X=Cl, Br, I or NCS have been synthesized and characterized. The crystal and molecular structures of Co(Phca2en)Cl2 (2), Ni(Phca2en)Br2 (5) and Zn(Phca2en)Cl2 (6) were determined by X-ray crystallography from single-crystal data. Complexes 2 and 5 are isomorph and isostructure, in which the coordination polyhedron about the central metal ion is distorted tetrahedron with Cl---Co---Cl, 110.17(6)°; N---Co---N, 84.16(13)° and Cl---Zn---Cl, 112.02(6)°; N---Zn---N, 83.45(16)°. The complex 5 crystallizes in triclinic system with two molecules per asymmetric unit, both having nickel ion in distorted tetrahedral geometry, Br---Ni---Br, 122.645(18)° and 125.729(18)°; N---Ni---N, 84.63(9)° and 85.08(9)°. These structures consist of intermolecular hydrogen bonds of the type C---HX. The formation of the C---HM weak intramolecular hydrogen bonds due to the trapping of C---H bonds in the vicinity of the metal atoms are reported for 2, 5 and 6. A 1H NMR study of Zn complexes gives further evidence for the presence of such interactions and their significance. The spectral properties of the above complexes are also discussed. 相似文献
88.
ABSTRACT In this study, graphene oxide (GO) was synthesized using Hummers, modified Hummers and improved Hummers methods, and then freestanding membranes were prepared based on these materials. Effects of different GO preparation methods on C/O ratio and interlayer spacing of freestanding membranes were studied. Structure of these membranes was studied by X-ray diffraction, contact angle, XRF, FT-IR, and FESEM methods. Also, permeability of ammonia, dichloromethane, and water vapor was investigated through these membranes. Results showed that, the sample prepared by the Hummers method had lower C/O ratio, smoother surface and lower permeability for polar species, such as water and ammonia vapors, than nonpolar materials. Membranes prepared using Improved Hummers method showed the least permeability against nonpolar vapors such as dichloromethane. 相似文献
89.
An experimental and theoretical analysis to separate CO2 using facilitated transport membranes immobilized with different aqueous single and mixed amine solutions have been performed. The membranes containing monoethanolamine (MEA), diethanolamine (DEA), monoprotonated ethylenediamine (EDAH+) and piperazine (PZ), as well as aqueous blends of PZ with MEA, DEA or EDAH+ were considered. The aqueous solution of PZ showed the highest CO2 permeation rate with respect to other single amine solutions. Therefore blends of PZ with MEA, DEA and EDAH+ increased the permeance of carbon dioxide through mixed amine membranes. 相似文献
90.
Moslem Afzali Tayebeh Shamspur Ali Mostafavi 《International journal of environmental analytical chemistry》2019,99(4):328-342
In the present work, a simple procedure is presented for the extraction and determination of pre-concentrated trace amounts of palladium ions through solid phase extraction (SPE) and flame atomic absorption spectrophotometry. This process was performed using Nylon-66/5-(4-dimethylaminobenzylidene) rhodanine composite nanofibres. These nanofibres were produced under optimised conditions via two-axial electrospinning technique and characterised by scanning electron microscopy and Fourier-transform infrared spectroscopy. The effect of experimental parameters including solution pH, the type and volume of eluent and contact time was investigated in extraction and desorption process. Under the optimised conditions, good linearity in the range of 0.07–8 μg L?1 and low detection limit of 0.015 μg L?1 were obtained. High enrichment factor of 187.5 and good relative standard deviation of ±2.2% at 5 μg L?1 of palladium had been achieved. The sorbent capacity for palladium adsorption was obtained 27 mg palladium per gram of nanofibres. So, the SPE was successfully applied to pre-concentrate and determine Pd(II) ions with flame atomic absorption spectrophotometer in real samples. 相似文献