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111.
Zhangzhen He Jun-Ichi Yamaura Yutaka Ueda Wendan Cheng 《Journal of solid state chemistry》2009,182(9):2526-2529
Based on the phase diagram of CoO–V2O5 system, single crystals of Co2V2O7 are grown using V2O5 as self-flux at a slow cooling rate. The quality of grown crystals is analyzed by X-ray powder diffraction and electron probe microanalysis techniques. Magnetic properties are investigated by means of susceptibility, magnetization, and heat capacity measurements. Our experimental results suggest that Co2V2O7 is a three-dimensional antiferromagnet, in which two magnetic transitions may occur at low temperature and a spin-flop-like transition may occur at the applied field along the b-axis. By contrast to Ni2V2O7, it is suggested that similar and different magnetic properties may arise from their similar crystal structures and different magnetic ions, respectively. 相似文献
112.
Four kinds of arenedisulphonyl chlorides as condensing reagents for oligodeoxyribonucleotide synthesis have been synthesised and their condensing abilities were examined in the synthesis of thymidylyl(3'-5') thymidine. Among them, mesitylenedisulphonyl chloride (MDS) and isodurenedisulphonyl chloride (DDS) proved to be effective for condensation and for separation of the product from the 5'-sulphonated by-product formed simultaneously. This paper describes detailed studies on the selective removal of one of two phenylthio groups by means of phosphinates from S,S-diphenyl deoxyribonucleoside 3'-phosphorodithioate derivatives, which were successfully used as the starting building units for the liquid phase synthesis of a dodecadeoxyribonucleotide, dCATTATTAATAC. 相似文献
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115.
Magnetic properties of SrCo2V 2O8 single crystal are investigated by means of ac magnetic susceptibility, dc magnetization and heat capacity measurements. The results show that SrCo2V 2O8 possesses two canted antiferromagnetic transitions at ∼5 and ∼3 K, which is different from isostructural BaCo2V 2O8 with only one antiferromagnetic transition at ∼5 K. We suggest that such different magnetic properties are mainly due to their different structural symmetry. 相似文献
116.
Ando K Akai Y Kunitomo J Yokomizo T Nakajima H Takeuchi T Yamashita M Ohta S Ohishi T Ohishi Y 《Organic & biomolecular chemistry》2007,5(4):655-663
A novel seven-membered lactam formation method has been established by intramolecular ring closure reaction of 4-bromo-(E)-3-[(2-alkylvinyl)carbonylamino]benzo[b]furans under Heck coupling conditions. A number of furo[2,3,4-jk][2]benzazepin-4(3H)-ones, tricyclicbenzo[b]furans, have been prepared by this method and evaluated for their leukotriene B(4) (LTB(4)) receptor and poly(ADP-ribose)polymerase-1 (PARP-1) inhibitory activities. 相似文献
117.
Loos DC Habuchi S Flors C Hotta J Wiedenmann J Nienhaus GU Hofkens J 《Journal of the American Chemical Society》2006,128(19):6270-6271
Proteins from the family of the green fluorescent protein (GFP) are presently extensively used in molecular and cellular biology. Recent studies suggest that isomerization of the chromophore occurs upon excitation and is involved in nonradiative deactivation. Using Raman spectroscopy, we report on photoinduced cis-trans isomerization in the red fluorescent protein eqFP611 from the sea anemone Entacmaea quadricolor. The crystal structure of eqFP611 shows that the chemical structure of the chromophore, p-hydroxybenzylidene-imidazolinone with an extended -conjugated system, is nearly identical to the chromophore of other red fluorescent proteins such as DsRed and HcRed. However, the chromophore of eqFP611 has a trans configuration whereas the chromophore of DsRed has a cis configuration. Upon irradiation with 532-nm light, the absorption of eqFP611 peaking at 559 nm diminished, and concomitantly a drastic decrease in the quantum yield of fluorescence as well as more complex decay kinetics was observed. Upon irradiation, changes in the Raman spectrum of eqFP611 were observed, and the relative intensities and peak positions of the irradiated eqFP611 showed striking similarity with the peaks in the Raman spectrum of DsRed. These observations are tentatively interpreted as trans-to-cis isomerization of the chromophore taking place upon irradiation together with the opening of new, nonradiative pathways. 相似文献
118.
Kimura S Suzuki H Maejima T Mori H Yamaura J Kakiuchi T Sawa H Moriyama H 《Journal of the American Chemical Society》2006,128(5):1456-1457
To investigate the insulating state of the pressure-induced superconductor, beta-(meso-DMBEDT-TTF)2PF6, we have carried out X-ray analysis at 11.5 K. In an asymmetric unit, there exist two crystallographically independent donor molecules, caused by charge separation. In the column structure, the arrangement of the charge-rich (r) and -poor (p) donor molecules is as rrpprrpp, which affords "checkerboard"-type charge ordering. 相似文献
119.
Polyelectrolyte multilayer thin films were prepared by an alternate deposition of poly(allylamine hydrochloride) (PAH) and anionic polysaccharides {carboxymethylcellulose (CMC) and alginic acid (AGA)} on the surface of a gold (Au) disk electrode, and the binding of ferricyanide [Fe(CN)(6)](3)(-) and hexaammine ruthenium ions [Ru(NH(3))(6)](3+) to the films was evaluated. Poly(acrylic acid) (PAA) was also employed as a reference polyanion bearing carboxylate side chains. A quartz-crystal microbalance study showed that PAH-CMC and PAH-AGA multilayer films grow exponentially as the number of depositions increases. The thicknesses of five bilayers of (PAH-CMC)(5) and (PAH-AGA)(5) films were estimated to be 150 +/- 20 and 90 +/- 15 nm, respectively, in the dry state. The PAH/polysaccharide multilayer film-coated Au electrodes exhibited a redox response to the [Fe(CN)(6)](3)(-) ion dissolved in solution, irrespective of the sign of the surface charge of the film, suggesting the high permeability of the films to the [Fe(CN)(6)](3)(-) ion. In contrast, the PAH-PAA film-coated Au electrodes exhibited a redox response only when the outermost surface of the film was covered with a positively charged PAH layer. However, the permeation of the [Ru(NH(3))(6)](3+) cation was severely suppressed for all of the multilayer films. It was possible to confine the [Fe(CN)(6)](3)(-) ion in the films by immersing the film-coated electrodes in a 1 mM [Fe(CN)(6)](3)(-) solution for 15 min. Thus, the [Fe(CN)(6)](3)(-)-confined electrodes exhibited a cyclic voltammetric response in the [Fe(CN)(6)](3)(-) ion-free buffer solution. The loading of the [Fe(CN)(6)](3)(-) ion in the films was higher when the surface charge of the film was positive and increased with increasing film thickness. It was also found that the [Fe(CN)(6)](3)(-) ion confined in the films serves as an electrocatalyst that oxidizes ascorbic acid in solution. 相似文献
120.
Dr. Aiichiro Nagaki Yuya Moriwaki Suguru Haraki Akira Kenmoku Naofumi Takabayashi Atsushi Hayashi Prof. Dr. Jun-Ichi Yoshida 《化学:亚洲杂志》2012,7(5):1061-1068
The use of Pd catalysts that contained a carbene ligand, such as PEPPSI-SIPr, speeded up the Murahashi coupling of ArLi with ArBr, by enabling its integration with the Br/Li exchange of ArBr with BuLi in flow. Space integration realized the rapid cross-coupling of two different ArBr substrates. However, the cross-coupling reaction with vinyl halides could not be achieved under similar conditions. Pd(OAc)2 was an effective catalyst, and the space integration of the Br/Li exchange of ArBr with BuLi and the Murahashi coupling with vinyl halides was successfully achieved. 相似文献