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521.
We have succeeded in synthesizing a new Au(III) complex coordinated by a dihydro-TTF-ditiolato ligand, dhdt2? (4,5-dihydrotetrathiafulvalene-4,5-dithiolato) as a tetrabutlylammoium or tetraphenylphosphonium salt. Crystal structural analysis of (Ph4P)[Au(dhdt)2] revealed that the Au(III) ion adopts a square planar coordination and the mean Au–S bond length suggests the Au ions are in the trivalent Au(III) state. A neutral complex, [Au(dhdt)2], was obtained by the electrochemical oxidation of (n-Bu4N) [Au(dhdt)2]. Conducting behavior of [Au(dhdt)2] was semiconductive with conductivity at room temperature of 8.3 Scm?1 and activation energy of 23 meV. Magnetic susceptibility of [Au(dhdt)2] was well explained by the sum of the Curie and temperature independent components. 相似文献
522.
Wataru Ueda Damian Vitry Tomokazu Kato Nobufumi Watanabe Yusuke Endo 《Research on Chemical Intermediates》2006,32(3):217-233
Mo-V-O-based complex metal oxide catalysts were synthesized hydrothermally for the first time, characterized structurally
and tested in the selective oxidation of propane to acrylic acid, and the results obtained were compared on the basis of catalyst
crystal structures in order to clarify key aspects of alkane selective oxidation over multifunctional metal oxide catalysts.
The catalysts tested were black solids of rod-shaped crystals, which had a layer structure in the direction of fiber axis
and various high dimensional arrangements of metal octahedra in the cross-section plane. A strong dependency on the octahedra
arrangements and a facet dependency were observed, and the roles of metal elements in the course of selective oxidation of
propane were clarified by comparing the catalytic performance of various Mo-V-O-based catalysts. We discuss the multi-functional
character derived from high dimensional structures of the catalysts and mechanism of the selective oxidation of propane. 相似文献
523.
Mitsuru Tashiro Takashi Fujimoto Kazuo Furihata Yohei Sakaki Takako Hirano Wataru Hakamata 《Journal of carbohydrate chemistry》2016,35(7):378-386
Enzymatic synthesis of trisaccharides from N-acetylsucrosamine and lactose utilizing the transgalactosylation activity of Aspergillus oryzae β-galactosidase provided two reaction products. Structure analyses by various 2D NMR spectroscopy and MS indicated that the products were β-D-fructofuranosyl β-D-galactopyranosyl-(1→6)-2-acetamido-2-deoxy-α-D-glucopyranoside and β-D-galactopyranosyl-(1→6)-β-D-fructofuranosyl-(2?1)-2-acetamido-2-deoxy-α-D-glucopyranoside. Moreover, J-resolved-HMBC experiments indicated that the conformations around the glycosidic bonds of these trisaccharides were very similar. Examination about the pH and thermal stabilities of the glycosidic bonds in the GlcNAc–Fru moiety of the two trisaccharides indicated apparent difference. 相似文献
524.
Dr. Zhenxin Zhang Dr. Masahiro Sadakane Dr. Norihito Hiyoshi Dr. Akihiro Yoshida Prof. Dr. Michikazu Hara Prof. Dr. Wataru Ueda 《Angewandte Chemie (International ed. in English)》2016,55(35):10234-10238
The application of nanocatalysis based on metal oxides for biomass conversion is of considerable interest in fundamental research and practical applications. New acidic transition‐metal oxide molecular wires were synthesized for the conversion of cellulosic biomass. The ultrafine molecular wires were constructed by repeating (NH4)2[XW6O21] (X=Te or Se) along the length, exhibiting diameters of only 1.2 nm. The nanowires dispersed in water and were observed using high‐angle annular dark‐field scanning transmission electron microscopy. Acid sites were created by calcination without collapse of the molecular wire structure. The acidic molecular wire exhibited high activity and stability and promoted the hydrolysis of the glycosidic bond. Various biomasses including cellulose were able to be converted to hexoses as main products. 相似文献
525.
Wataru Horie Ulf Olsson Kenji Aramaki 《Journal of Dispersion Science and Technology》2017,38(12):1804-1810
This study deals with the formation of reverse vesicles based on the phase behavior of silicone surfactants. The surfactants, polyoxyethylene–polydimethylsiloxane and polyoxyethylene–polyoxypropylene–polydimethylsiloxane copolymer, were found to form lamellar liquid crystal phases in three different types of silicone oil upon the addition of a certain amount of water. A conventional method in which reverse vesicles are prepared by physically dispersing this lamellar liquid crystal phase in oil was employed in addition to a technique based on a temperature-induced phase transition. The particle sizes and stabilities of the resulting reverse vesicles were evaluated. 相似文献
526.
Understanding and Practical Use of Ligand and Metal Exchange Reactions in Thiolate‐Protected Metal Clusters to Synthesize Controlled Metal Clusters
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Yoshiki Niihori Sakiat Hossain Sachil Sharma Bharat Kumar Wataru Kurashige Yuichi Negishi 《Chemical record (New York, N.Y.)》2017,17(5):473-484
It is now possible to accurately synthesize thiolate (SR)‐protected gold clusters (Aun(SR)m) with various chemical compositions with atomic precision. The geometric structure, electronic structure, physical properties, and functions of these clusters are well known. In contrast, the ligand or metal atom exchange reactions between these clusters and other substances have not been studied extensively until recently, even though these phenomena were observed during early studies. Understanding the mechanisms of these reactions could allow desired functional metal clusters to be produced via exchange reactions. Therefore, we have studied the exchange reactions between Aun(SR)m and analogous clusters and other substances for the past four years. The results have enabled us to gain deep understanding of ligand exchange with respect to preferential exchange sites, acceleration means, effect on electronic structure, and intercluster exchange. We have also synthesized several new metal clusters using ligand and metal exchange reactions. In this account, we summarize our research on ligand and metal exchange reactions. 相似文献
527.
Wataru Ando Toshiaki Nagashima 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-2)
Abstract Dye sensitized photooxidation of sulfides proceeds by way of singlet oxygen to give sulfoxides and sulfones, and the evidence for several intermediates has been reported. We now report that photooxidation of aromatic sulfides gives the product of an unusual type; and the reaction may proceed by either superoxide or hydroperoxysulfurane. 9-Ethylthiofluorene was photooxidized in dichloromethane or acetone with methylene blue as sensitizer. Three main products were isolated and identified as fluorenone (15%), 9-fluorenyl ethyl sulfoxide (19%) and 1-hydroxyl-9-fluorenone (23%). 相似文献
528.
In a light-delivery system for laser-assisted magnetic recording, which provides high-areal-density storage by heating the
storage medium during the writing process, a laser diode light source and a near-field transducer must be efficiently coupled
using inexpensive optical devices. We describe a light-delivery system using an element for end-fire coupling and a spot-size
converter. To couple the light emitted from the end of an optical fiber to a spot-size converter inexpensively, a couple element
requiring no other lens elements between the fiber and converter was developed. A vertically multistepped and laterally tapered
waveguide suitable for fabrication by planar processing was also developed. These devices are well suited for practical use. 相似文献
529.
530.