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151.
Yamamoto C Nishikawa H Nihei M Shiga T Hedo M Uwatoko Y Sawa H Kitagawa H Taguchi Y Iwasa Y Oshio H 《Inorganic chemistry》2006,45(25):10270-10276
Reactions of K1.62[Pt(ox)2].2H2O and [Cu(bpy)(H2O)3](NO3)2 yielded partially oxidized one-dimensional (1D) bis(oxalato)platinates of [Cu(bpy)(H2O)n]6[Pt(ox)2]7.7H2O (n = 2, 3, or 4) (1) and [Cu(bpy)(H2O)n]8[Pt(ox)2]10.8H2O (n = 3 or 4) (2). The average oxidation numbers of the platinum ions in 1 and 2 are +2.29 and +2.40, respectively. Complexes 1 and 2 crystallize in the triclinic P and monoclinic C2/c space groups, respectively, and the [Pt(ox)2]n- anions are stacked along the crystallographic b axis with 7-fold periodicity for 1 and 10-fold periodicity for 2. In 1, an oxalato ligand in the platinum chain directly coordinates to a paramagnetic [Cu(bpy)(H2O)3]2+ ion, whereas no such direct coordination was observed for 2. The electrical conductivity of 2 at room temperature along the platinum chain is approximately 3 orders of magnitude smaller (sigma||= 1.3 x 10(-3) S cm(-1)) than that of 1 (sigma|| = 0.9-0.5 S cm(-1)), and the activation energies of 1 and 2 are 29 and 67 meV, respectively. The longest inter-platinum distances in 1 and 2 are 2.762 and 3.0082 A, respectively, and this is responsible for the lower electrical conductivity of 2. An X-ray oscillation photograph taken along the b axis of 1 reveals the 7-fold periodicity in the 1D chain, consistent with the period of the Peierls distortion estimated from the degree of partial oxidation. The semiconducting state of 1 can therefore be regarded as a commensurate Peierls state. The magnetoresistance of 1 at ambient pressure indicates no interaction between conduction electrons in the platinum chain and local spins of the paramagnetic CuII ions. Application of hydrostatic pressures of up to 3 GPa enhances electrical conduction, as is often seen as the usual pressure effect on the electrical conductivity, which is due to enhanced orbital (Pt-5dz2) overlap by pressure application. 相似文献
152.
Villeneuve M Ootsu R Ishiwata M Nakahara H 《The journal of physical chemistry. B》2006,110(36):17830-17839
We have investigated how the dynamics of surfactant molecules changes with the vesicle-micelle transition by (1)H NMR relaxation studies on the sodium decyl sulfate (SDeS)-decyltrimethylammonium bromide (DeTAB)-deuterium oxide system. The study has been planned with reference to the phase diagram of the SDeS-DeTAB-water system deduced from thermodynamic analysis of the surface tension data. The spin-lattice relaxation time (T(1)) and the spin-spin relaxation time (T(2)) are measured at 90 and 400 MHz at various total molalities, m, and compositions, X(2), of the surfactants. The data were analyzed according to the "two-step" model developed by Wennerstr?m et al. and molecular dynamics of the surfactant is discussed from the viewpoint of correlation time tau(f) associated with the local fast motion of the surfactant molecule, correlation time tau(s) associated with the slow overall motions of the aggregate and surfactant molecules within it, and local order parameter S. We find tau(s) of vesicles is an order of magnitude larger than that of micelles signifying that the tumbling of vesicle particles and surfactant diffusion over the vesicle are much slower than those for micelle. Tau(f) and S for vesicles are also larger than those for micelles. Molecular environments of the surfactant are also discussed from the dependence of the chemical shifts on m at constant X(2) or from that on X(2) at constant m. When the chemical shifts in vesicle and micelle are compared at constant m, the chemical shifts in vesicle are displaced to a lower magnetic field than those in micelle, which implies that the surfactant molecules are arranged more closely to each other in the vesicle than in the micelle. 相似文献
153.
Rueff JP Itié JP Taguchi M Hague CF Mariot JM Delaunay R Kappler JP Jaouen N 《Physical review letters》2006,96(23):237403
We report on the most complete investigation to date of the -electron properties at the transition in elemental Ce by resonant inelastic x-ray scattering (RIXS). The Ce 2p3d-RIXS spectra were measured directly in the bulk material as a function of pressure through the transition. The spectra were simulated within the Anderson impurity model. The occupation number n(f) and f double occupancy were derived from the calculations in both gamma and alpha phases in the ground state. We find that the electronic structure changes result mainly from band formation of 4f electrons which concurs with reduced electron correlation and increased Kondo screening at high pressure. 相似文献
154.
Hisayuki Horai Masanori Arita Shigehiko Kanaya Yoshito Nihei Tasuku Ikeda Kazuhiro Suwa Yuya Ojima Kenichi Tanaka Satoshi Tanaka Ken Aoshima Yoshiya Oda Yuji Kakazu Miyako Kusano Takayuki Tohge Fumio Matsuda Yuji Sawada Masami Yokota Hirai Hiroki Nakanishi Kazutaka Ikeda Naoshige Akimoto Takashi Maoka Hiroki Takahashi Takeshi Ara Nozomu Sakurai Hideyuki Suzuki Daisuke Shibata Steffen Neumann Takashi Iida Ken Tanaka Kimito Funatsu Fumito Matsuura Tomoyoshi Soga Ryo Taguchi Kazuki Saito Takaaki Nishioka 《Journal of mass spectrometry : JMS》2010,45(7):703-714
MassBank is the first public repository of mass spectra of small chemical compounds for life sciences (<3000 Da). The database contains 605 electron‐ionization mass spectrometry(EI‐MS), 137 fast atom bombardment MS and 9276 electrospray ionization (ESI)‐MSn data of 2337 authentic compounds of metabolites, 11 545 EI‐MS and 834 other‐MS data of 10 286 volatile natural and synthetic compounds, and 3045 ESI‐MS2 data of 679 synthetic drugs contributed by 16 research groups (January 2010). ESI‐MS2 data were analyzed under nonstandardized, independent experimental conditions. MassBank is a distributed database. Each research group provides data from its own MassBank data servers distributed on the Internet. MassBank users can access either all of the MassBank data or a subset of the data by specifying one or more experimental conditions. In a spectral search to retrieve mass spectra similar to a query mass spectrum, the similarity score is calculated by a weighted cosine correlation in which weighting exponents on peak intensity and the mass‐to‐charge ratio are optimized to the ESI‐MS2 data. MassBank also provides a merged spectrum for each compound prepared by merging the analyzed ESI‐MS2 data on an identical compound under different collision‐induced dissociation conditions. Data merging has significantly improved the precision of the identification of a chemical compound by 21–23% at a similarity score of 0.6. Thus, MassBank is useful for the identification of chemical compounds and the publication of experimental data. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
155.
Liquid chromatography/electrospray ionization mass spectrometry (LC/ESI‐MS) is suitable for analysis of glycosphingolipids such as fragile gangliosides avoiding the use of the sialic acid elimination. However, it was not possible to distinguish the structural isomers such as GD1a and GD1b with reversed‐phase LC/ESI‐MS by hydrophobic interaction. Here we report an effective method for targeted analysis of theoretically expanded ganglioside molecular species including structural isomers by hydrophilic interaction liquid chromatography (HILIC)/ESI‐MS with multiple reaction monitoring (MRM). As a result of MRM analysis of glycosphingolipid mixtures from porcine brain, each of the lipid classes was detected within 25 min in the following order: sulfatides > GM3 > GM2 > GM1 > GD3 > GD1a > GD2 > GD1b > GT1a > GT1b > GQ1b. For the advanced application, localization analysis of postnatal day 15 (P15) mouse cerebellum layered structures was carried out by combination of MRM and laser microdissection (LMD). As a result, GM3, GD1a, GT1b and GQ1b were abundantly detected in the molecular and granular layers, whereas GM1 was widely presented in each layered structure. These gangliosides were mainly composed of d18:1‐18:0 and d18:1‐20:0, but GM3 was d18:1‐16:0 and d18:1‐20:0. Meanwhile, sulfatide molecular species were mostly localized in the myelinated fibers and scarcely found in the molecular layer. These results suggested that our method is suitable to detect a variety of ganglioside classes and sulfatides with high sensitivity at the molecular species level and effective for localization analysis of these glycosphingolipids from mouse brain sections. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
156.
Hideo Ogiso Kazuhiro Nakamura Yutaka Yatomi Takao Shimizu Ryo Taguchi 《Rapid communications in mass spectrometry : RCM》2010,24(4):436-442
Phosphatidylinositol phosphates (PtdInsPs) are present within the nucleus, as well as in the membrane. In this mass spectrometry study, different acyl‐containing species of endonuclear PtdInsPs were analyzed in order to clearly understand the role of individual molecular species. A (34:1) acyl‐containing phosphatidylinositol bisphosphate [PtdInsP2(34:1)] and PtdInsP2(36:1) were preferentially detected in envelope‐less nuclei prepared from various cultured human cells, while PtdInsP2(38:4) was not a major component within these nuclei. A significant amount of PtdInsP2(34:0) was detected in the HeLa cell nucleus, but not in the A431 and THP‐1 cell nuclei. During the cell cycle in HeLa cells, PtdInsP2(34:0) levels increased in the early G1 phase, and then gradually decreased through S phase, while PtdInsP2(34:1) levels tended to decrease only in late G1 phase and PtdInsP2(38:4) did not change significantly. Thus, individual PtdInsP2 species apparently play different roles in nuclear events based on individual regulation of endonuclear levels. The non‐arachidonate‐containing species were also detected in normal human blood and fluids, suggesting that these minor species may have unique functions in the human body. The techniques used in this study will be applied to clinical studies on a PtdInsPs metabolism. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
157.
Xin -Tong Zhang Taketo Taguchi Hai -Bin Wang Qing -Bo Meng Osamu Sato Akira Fujishima 《Research on Chemical Intermediates》2007,33(1-2):5-11
The stability of the TiO2/ruthenium dye/CuI solid-state solar cell was investigated under continuous simulated sunlight illumination. The cells showed fast degradation under full-spectrum sunlight illumination, but showed rather good stability when the ultraviolet part of the illumination was removed. XPS measurements showed evidence that TiO2 could oxidize CuI in the presence of UV light. The photo-degradation mechanism of the cells is thus discussed on the basis of the photo-oxidative function of TiO2. The long-term stability of the solid-state dye-sensitized solar cell (DSSC) was found to be improved under simulated sunlight by coating the TiO2 porous electrode with an ultra-thin MgO layer, which was able to block the photo-oxidative activity of the TiO2. 相似文献
158.
Yoshiro Kobayashi Takeo Taguchi Norio Kanuma Nobuo Ikekawa Jun-ichi Oshida 《Tetrahedron letters》1981,22(43):4309-4312
Two new fluorinated 25-hydroxyvitamin D3 analogs, 26,26,26-trifluoro- 25-hydroxy () and 27-nor-26,26,26-trifluoro-25-hydroxyvitamin D3 (), were prepared from 24-phenylsulfonyl 25,26,27-triorcholest-5-en-3β-yl tetrahydropyranyl ether (). 相似文献
159.
The cubic perovskite Sr(Co1?xMnx)O3 has a maximum value of a-axis at x = 0.3 and a change of spin state of Co4+ ion from low to high. To elucidate these properties, the isotropic temperature factor (B) of strontium, cobalt, manganese, and oxygen atoms for x = 0, 0.1, 0.5, 0.8, and 0.1 have been derived from powder X-ray diffraction measurements. The isotropic temperature factor of oxygen for x = 0, 0.1, and 1.0 is small and that for x = 0.5 and 0.8 is large. This fact suggests that the oxygen ion deviates from the center of the CoOMn bond in the solid solutions with . Larger CoO6 octahedra and smaller MnO6 octahedra, which are connected by corner sharing of oxygens of the octahedron, are distributed statistically. 相似文献
160.
We developed a method to prepare hemispherical hollow silica microcapsules (HHSM) with different affinity surfaces using spherical vaterite calcium carbonate (SVCC) as a template. The preparation process composed of the adhesion of calcium carbonate onto the surface of methyl methacrylate (MMA) droplets followed by suspension polymerization, the partial etching of calcium carbonate on the polymethyl methacrylate (PMMA) mother particle, the formation of silicon dioxide powder by sol–gel reaction and their deposition onto the etched flat surface of calcium carbonate, the surface modification of deposited silicon dioxide with silane coupling agent, the removal of the mother particle with acetone, the formation of silicon dioxide powder by sol–gel reaction and deposition onto the exposed hemispherical surface of calcium carbonate, and the surface modification of deposited silicon dioxide with silane coupling agent. The synthesized microcapsules had a complete hemispherical structure and both hydrophilic and hydrophobic surfaces. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献