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81.
Morita Y Murata T Fukui K Yamada S Sato K Shiomi D Takui T Kitagawa H Yamochi H Saito G Nakasuji K 《The Journal of organic chemistry》2005,70(7):2739-2744
[structure: see text] Novel hydrogen-bonded charge-transfer salts of TCNQ with mono- and diprotonated 4,4'-biimidazolium were synthesized in order to demonstrate the high potential of the 4,4'-biimidazole system in a molecular conductor from the viewpoint of crystal engineering and electronic modulation. Crystal structure analyses of neutral 4,4'-biimidazole and TCNQ salts revealed the formation of two types of hydrogen-bonding modes of the 4,4'-biimidazole moiety depending on the protonated states. Neutral 4,4'-biimidazole possessed a linear chain mode of hydrogen-bonding to construct two-dimensional network. In the TCNQ salt of monoprotonated 4,4'-biimidazolium, the 4,4'-biimidazole moiety formed a dimer by a complementary mode of hydrogen-bonding. In contrast, the salt of diprotonated 4,4'-biimidazolium showed a double linear chain mode of hydrogen-bonding to construct a three-dimensional network. The formation of two types of hydrogen-bonding modes made the difference in the stacking patterns of TCNQ columns and in their transport properties. The TCNQ salt of diprotonated 4,4'-biimidazolium exhibited high electrical conductivity (sigma(rt) = 1.1 x 10(-1) S cm(-1)). 相似文献
82.
Tetsuro Kawahara Kazuhiro Doushita Hiroaki Tada 《Journal of Sol-Gel Science and Technology》2003,27(3):301-307
Anatase TiO2 films (thickness = 50 nm) were formed in shape of stripes (width = 1.6 mm, interval = 0.4 mm) by gravure printing on commercially available SnO2 coated soda-lime glass substrates (dimension = 300 × 300 mm). Its photocatalytic activity was examined for the gas-phase oxidation of CH3CHO in comparison with a simple TiO2 photocatalyst formed on a silica glass. The patterned TiO2/SnO2 bilayer type photocatalyst showed a high photocatalytic activity in an H2O bearing atmosphere. On the other hand, neither the patterning nor stacking effect was observed for the same reaction under dry conditions. These results could be explained in terms of the reducing potential of the electrons in the conduction band of the SnO2 layer. 相似文献
83.
Some water-soluble organic iodine compounds (aqueous solution) can be analyzed for iodine by isotopically exchanging with labelled elementary iodine (organic solution). The method is applicable to exchange systems in which the rate of the exchange is rather small but measurable, before the exchange equilibrium is attained. The iodine content of iodoaromatic amino acids such as 5-iodouracil and 3,5-diiodotyrosine can be determined within an error of ±4%. 相似文献
84.
Tsai P Ichikawa K Mailer C Pou S Halpern HJ Robinson BH Nielsen R Rosen GM 《The Journal of organic chemistry》2003,68(20):7811-7817
Apparent rate constants, at acidic pH and neutral pH for the reaction of a family of ester-containing 5-carboxyl-5-methyl-1-pyrroline N-oxides with superoxide (O2*-) were estimated, using ferricytochrome c as a competitive inhibitor. It was of interest to note that the rate constants were similar among the different nitrones and not that significantly different from that found for 5-(diethoxyphosphoryl)-5-dimethyl-1-pyrroline N-oxide. At acidic pH, the rate constant for spin trapping O2*- was 3-fold greater than that at physiological pH. Subsequent experiments determined the half-life of aminoxyls, derived from the reaction of these nitrones with O2*-. The EPR spectra were modeled by using a global analysis method. The results clearly demonstrated that EPR spectra of all the aminoxyls were inconsistent with a model that included a single gamma-hydrogen splitting. A better interpretation modeled them as two diastereomers with identical nitrogen splittings and slightly different beta-hydrogen splittings. Detailed line width analyses slightly favored an equal line width-unequal population ratio for the two diastereomers. 相似文献
85.
This review covers the literature on simple indole alkaloids and those with a nonrearranged monoterpenoid unit from the beginning up to the end of 2004. Newly isolated alkaloids, structure determinations, total synthesis and biological activities are included. 相似文献
86.
Tadamasa Shida Yasufumi Takahashi Hiroyuki Hatano Masashi Imamura 《Chemical physics letters》1975,33(3):491-494
Radical-anions of iodine, bromine, and monoiodochloride are produced in γ-irradiated amorphous solids at 77 K, and their electronic and ESR spectra measured. On limited warming of the irradiated solution dimerization by the reaction I2? + I2 → I4? occurs to produce the same species as reported by Fornier de Violet et al. The electronic structure of the dimeric anion is discussed in comparison with the monomeric anion. 相似文献
87.
Itoh T Shichi T Yui T Takahashi H Inui Y Takagi K 《The journal of physical chemistry. B》2005,109(8):3199-3206
The present study is an investigation of a reversible thermal color change induced in lamella hybrids of poly(diacetylenecarboxylates) incorporated in layered double hydroxide (LDH) nanosheets. These poly-[m,n]/LDH hybrids prepared by the photo- or gamma-ray-induced polymerization of diacetylenecarboxylates, i.e., CH(3)(CH(2))(m)()(-)(1)CC-CC(CH(2))(n)()(-)(1)CO(2)(-) (mono-[m,n]), and intercalated in LDH lamella sheets, were observed to develop colors ranging from yellow to blue. The change in color was found to depend greatly on the alkyl carbon numbers of the mono-[m,n] (m,n = 10,11; 5,11; 10,5; 16,1) values. Moreover, the conformational alignment of the mono-[m,n] within the LDH was observed to be a crucial factor in color development, which was greatly affected by the intercalation degrees and extent of poly(ene-yne) linkage elongation of the polymers. For the poly-[m,n]/LDH hybrids investigated, a reversible color change was found to occur repeatedly and remarkably for the poly-[10,11]/LDH hybrid. This color change occurred at temperatures between ca. 20 and 80 degrees C back and forth from purple red to bright orange, in stark contrast to the irreversible color change for poly-[10,11] without LDH. Moreover, DSC and Raman spectroscopic studies of the LDH hybrids showed that the thermochromic temperature corresponded to the phase transition temperature of 80 degrees C. XRD analysis also indicated that the poly-[m,n]/LDH hybrid could retain its lamella structure during such thermochromic color changes, enabling conformational recovery in the polymer chains by a cooling down of the hybrids to temperatures lower than the transition temperature, while the nonhybrid poly-[10,11] powders exhibited an irreversible color change at 60 degrees C, above which the polymer powder turned amorphous. 相似文献
88.
-Butyrolactone (hereafter abbreviated GBL) is produced by the two-stage hydrogenation of maleic anhydride(MAH) in the liquid phase: the hydrogenation of MAH to succinic anhydride(SAH) in the first stage and the subsequent hydrogenation of SAH to GBL in the second stage. A novel ruthenium catalyst system consisting of Ru salts, trialkylphosphine and p-toluene sulfonic acid (p-TsOH) was found very effective for the hydrogenation of SAH affording GBL, which exhibited excellent catalyst performance, exceeding 97% selectivity for GBL and high activity. 相似文献
89.
Kazuhiro Watanabe Noboru Akino Tetsuo Aoyagi Noboru Ebisawa Yukio Fujiwara Atsusi Honda Takashi Inoue Takao Itoh Mikito Kawai Minoru Kazawa Junichi Koizumi Masaaki Kuriyama Kenji Miyamoto Naoki Miyamoto Kazuhiko Mogaki Yoshihiro Ohara Tokumichi Ohga Yoshikazu Okumura Hiroshi Oohara Katsumi Ohshima Fujio Satoh Kazuhiko Shimizu Syunji Takahashi Hirotsugu Usami Katsutomi Usui Masahiro Yamamoto Takeshi Yamazaki 《Radiation Physics and Chemistry》1997,49(6):631-639
A negative-ion-based neutral beam injector (N-NBI) has been constructed for JT-60U. The N-NBI is designed to inject 500 keV, 10 MW neutral beams using two ion sources, each producing a 500 keV, 22 A D− ion beam. In the preliminary experiment using one ion source, a D− ion beam of 13.5 A has been successfully accelerated with an energy of 400 keV (5.4 MW) for 0.12 s at an operating pressure of 0.22 Pa. This is the highest D− beam current and power in the world. Co-extracted electron current was effectively suppressed to the ratio of Ie/ID− < 1. The highest energy beam of 460 keV, 2.4 A, 0.44 s has also been obtained. To realize 1 MeV class NBI system for ITER (International Thermonuclear Experimental Reactor), demonstration of ampere class negative ion beam acceleration up to 1 MeV is an important mile stone. To achieve the mile stone, a prototype accelerator and a 1 MV, 1 A test facility called MeV Test Facility (MTF) were constructed. Up to now, an H− ion beam was accelerated up to the energy of 805 keV with an acceleration drain current of 150 mA for 1 s in a five stage electrostatic multi-aperture accelerator. 相似文献
90.
Distribution pattern of rare earth ions between water and montmorillonite and its relation to the sorbed species of the ions. 总被引:1,自引:0,他引:1
REE (rare earth element) distribution coefficients (Kd) between the aqueous phase and montmorillonite surface were obtained to investigate the relation between the REE distribution patterns and the species of REE sorbed on the solid-water interface. It was shown that the features in the REE patterns, such as the slope of the REE patterns, the tetrad effect, and the Y/Ho ratio, were closely related to the REE species at the montmorillonite-water interface. In a binary system (REE-montmorillonite) below pH 5, three features (a larger Kd value for a lighter REE, the absence of the tetrad effect, and the Y/Ho ratio being unchanged from its initial value) suggest that hydrated REE are directly sorbed as an outer-sphere complex at the montmorillonite-water interface. Above pH 5.5, the features in the REE patterns, the larger Kd value for heavier REE, the M-type tetrad effect, and the reduced Y/Ho ratio, showed the formation of an inner-sphere complex of REE with -OH group at the montmorillonite surface. In addition, the REE patterns in the presence of humic acid at pH 5.9 were also studied, where the REE patterns became flat, suggesting that the humate complex is dominant as both dissolved and sorbed species of REE in the ternary system. All of these results were consistent with the spectroscopic data (laser-induced fluorescence spectroscopy) showing the local structure of Eu(III) conducted in the same experimental system. The present results suggest that the features in the REE distribution patterns include information on the REE species at the solid-water interface. 相似文献