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991.
A general and convenient palladium-catalyzed Sonogashira reaction of in situ generated arenediazonium salts has been developed and various internal arylalkynes are produced in good yields under mild conditions. 相似文献
992.
Starting from commercially available amines and propargylamides a variety of substituted imidazoles were synthesized via a novel hydroamination-cyclization sequence. The target compounds are obtained in good to excellent yields in the presence of catalytic amounts of zinc triflate. 相似文献
993.
Jarre G Liang Y Betz P Lang D Krueger A 《Chemical communications (Cambridge, England)》2011,47(1):544-546
Stable covalent C-C bonding of aromatic moieties has been achieved using Diels-Alder reactions on surface-annealed nanodiamond. Subsequent functionalisation leads to tunable surface properties and molecule-like behaviour. 相似文献
994.
A series of novel furan-2-yl(phenyl)methanone derivatives were synthesized, and their structures were established on the basis of 1H-NMR, 13C-NMR and mass spectral data. All the prepared compounds were screened for their in vitro protein tyrosine kinase inhibitory activity and several new derivatives exhibited promising activity, which, in some cases, was identical to, or even better than that of genistein, a positive reference compound. The preliminary structure-activity relationships of these compounds were investigated and are discussed. 相似文献
995.
Ling-Bin Kong Mao-Cheng Liu Jun-Wei Lang Min Liu Yong-Chun Luo Long Kang 《Journal of Solid State Electrochemistry》2011,15(3):571-577
A new porous cobalt hydroxide film has been successfully electrodeposited on nickel foam from 0.1?M cobalt nitrate electrolyte at ?1.0?V vs. SCE without adding any surfactant. The microstructure and surface morphology of prepared cobalt hydroxide films were physically characterized by X-ray diffraction analysis and scanning electron microscopy. The results indicate that an interlaced network structure was obtained. The effects of electrodeposition time, deposition potential, and different substrates on the specific capacitance and microstructure of prepared porous ??-Co(OH)2 thin film were systematically studied. The results indicate that the film deposited on nickel foam at ?1.0?V has excellent electrochemical properties. A maximum specific capacitance of 1473?F?g?1 could be achieved at a current density of 2?A?g?1. 相似文献
996.
997.
998.
999.
A multiwalled carbon nanotubes (MWNT) modified glassy carbon electrode (GCE) coated with poly(orthanilic acid) (PABS) film
(PABS–MWNT/GCE) has been fabricated and used for simultaneous determination of dopamine (DA) and uric acid (UA) in the presence
of ascorbic acid (AA) by differential pulse voltammetry (DPV). Scanning electron microscopy, Fourier transform infrared spectra,
and electrochemical techniques have been used to characterize the surface morphology of the PABS–MWNT composite film and the
polymerization of ABS on electrode surface. In comparison with the bare GCE and the MWNT-modified GCE, the PABS–MWNT composite
film-modified GCE, which combines the advantages of MWNT and the self-doped PABS, exhibits good selectivity and sensitivity
for the simultaneous and selective determination of UA and DA in the presence of AA. Due to the different electrochemical
responses of AA, DA, and UA, PABS–MWNT/GCE can resolve the overlapped oxidation peak of DA and UA into two well-defined voltammetric
peaks with enhanced current responses using both cyclic voltammetry (CV) and DPV. The peak potential separations between DA
and UA are 170 mV using CV and 160 mV using DPV, respectively, which are large enough for the selective and simultaneous determination
of these species. In the presence of 0.5 mM AA, the DPV peak currents are linearly dependent on the concentration of UA and
DA in the range of 6–55 and 9–48 μM with correlation coefficients of 0.997 and 0.993, respectively. The detection limits (S/N = 3) for detecting UA and DA are 0.44 and 0.21 μM, respectively. The PABS–MWNT/GCE shows good reproducibility and stability
and has been used for the simultaneous determination of DA and UA in the presence of AA in samples with satisfactory results. 相似文献
1000.
Tongyong Yang Kening Sun Zhengyu Lei Naiqing Zhang Ye Lang 《Journal of Solid State Electrochemistry》2011,15(2):391-397
LiNi0.5Mn1.5O4 cathode materials were successfully prepared by sol–gel method with two different Li sources. The effect of both lithium
acetate and lithium hydroxide on physical and electrochemical performances of LiNi0.5Mn1.5O4 was investigated by scanning electron microscopy, Fourier transform infrared, X-ray diffraction, and electrochemical method.
The structure of both samples is confirmed as typical cubic spinel with Fd3m space group, whichever lithium salt is adopted. The grain size of LiNi0.5Mn1.5O4 powder and its electrochemical behaviors are strongly affected by Li sources. For the samples prepared with lithium acetate,
more spinel nucleation should form during the precalcination process, which was stimulated by the heat released from the combustion
of extra organic acetate group. Therefore, the particle size of the obtained powder presents smaller average and wider distribution,
which facilitates the initial discharge capacity and deteriorates the cycling performance. More seriously, there exists cation
replacement of Li sites by transition metal elements, which causes channel block for Li ion transference and deteriorates
the rate capability. The compound obtained with lithium hydroxide exhibits better electrochemical responses in terms of both
cycling and rate properties due to higher crystallinity, moderate particle size, narrow size distribution and lower transition
cation substitute content. 相似文献