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81.
Okamoto A Kamei T Tanaka K Saito I 《Journal of the American Chemical Society》2004,126(45):14732-14733
Photostimulated hole transport through DNA duplexes immobilized on gold electrodes has been investigated. By modifying a gold electrode with a DNA duplex containing a photosensitizer, we have observed a sequence-dependent cathodic photocurrent. DNA acts as a good mediator for cathodic photocurrent when appropriate sequences are selected. 相似文献
82.
Cascade Synthesis of Five‐Membered Lactones using Biomass‐Derived Sugars as Carbon Nucleophiles
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Dr. Sho Yamaguchi Takeaki Matsuo Dr. Ken Motokura Dr. Akimitsu Miyaji Prof. Toshihide Baba 《化学:亚洲杂志》2016,11(11):1731-1737
We report the cascade synthesis of five‐membered lactones from a biomass‐derived triose sugar, 1,3‐dihydroxyacetone, and various aldehydes. This achievement provides a new synthetic strategy to generate a wide range of valuable compounds from a single biomass‐derived sugar. Among several examined Lewis acid catalysts, homogeneous tin chloride catalysts exhibited the best performance to form carbon–carbon bonds. The scope and limitations of the synthesis of five‐membered lactones using aldehyde compounds are investigated. The cascade reaction led to high product selectivity as well as diastereoselectivity, and the mechanism leading to the diastereoselectivity was discussed based on isomerization experiments and density functional theory (DFT) calculations. The present results are expected to support new approaches for the efficient utilization of biomass‐derived sugars. 相似文献
83.
Y. Ito J. Akimitsu M. Matsui S. Chikazumi 《Journal of magnetism and magnetic materials》1979,10(2-3):194-196
The magnetic form factor of a single crystal Fe0.66Ni0.34 Invar alloy was measured at room temperature and at liquid N2 temperature by means of the polarized neutron diffraction technique. The self-consistent form factor analysis was made possible with the use of a spin only Fe spherical form factor. 相似文献
84.
Ryo Ishida Setsuka Arii Wataru Kurashige Seiji Yamazoe Kiichirou Koyasu Yuichi Negishi Tatsuya Tsukuda 《催化学报》2016,(10):1656-1661
聚(N-乙烯基-2-吡咯烷酮)稳定的金簇合物(Au:PVP)的质谱结果表明,来源于合成前驱体的Cl吸附质主要存在于Au34和Au43簇合物上。金簇合物上Cl吸附质的数量不影响其催化有氧苯甲醇氧化性能,表明Cl原子与Au簇合物间存在较弱的键合作用。相反,用Br替代Au34和Au43簇合物上Cl显著抑制了其催化活性,但对其电子结构没有任何影响。这表明, Br原子与金簇合物的键合较强,在空间上堵塞了活性位。因Br吸附质而导致活性显著下降表明, Au34和Au43簇合物对Au:PVP催化活性起主要贡献。 相似文献
85.
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87.
Lenagh-Snow GM Jenkinson SF Newberry SJ Kato A Nakagawa S Adachi I Wormald MR Yoshihara A Morimoto K Akimitsu K Izumori K Fleet GW 《Organic letters》2012,14(8):2050-2053
Although there are 32 6-azidoheptitols, there are only 16 homonojirimycin (HNJ) stereoisomers. Two epimeric azidoalditols derived from d-mannose allow the synthesis in water of eight stereoisomers of HNJ. 相似文献
88.
H Noda K Motokura A Miyaji T Baba 《Angewandte Chemie (International ed. in English)》2012,51(32):8017-8020
The cooperative surface-catalysis strategy of a Br?nsted acid and an organic base can be extended to a metal complex and organic base pair. A silica-supported diaminopalladium complex and a tertiary amine were prepared and characterized. The Pd-catalyzed Tsuji-Trost reaction was enhanced significantly by the presence of the tertiary amine on the same silica surface as the Pd complex. 相似文献
89.
Norimichi Kojima Kazuhiro Ikeda Yasuhiro Kobayashi Tatsuya Tsukuda Yuichi Negishi Genta Harada Tadashi Sugawara Makoto Seto 《Hyperfine Interactions》2012,207(1-3):127-131
We have investigated the structures and electronic states of a series of glutathionate-protected Au clusters, Au n (SG) m with n = 10 ? ~55, using 197Au Mössbauer spectroscopy, which allows us to probe the local environment of the constituent Au atoms via isomer shift (IS) and quadrupole splitting (QS). The spectral profile abruptly changes on going from Au22(SG)17 to Au25(SG)18, then it smoothly changes to that of Au~55(SG)m. However, the spectral profile dramatically changes on going from Au~55(SG)m to the dodecanethiolate-protected Au cluster with average diameter of 2 nm. The 197Au Mössbauer spectra of glutathionate-protected Au clusters and dodecanethiolate-protected Au clusters were successfully analyzed on the basis of the structure and electronic state of Au25(SG)18. 相似文献
90.
Negishi Y Takasugi Y Sato S Yao H Kimura K Tsukuda T 《The journal of physical chemistry. B》2006,110(25):12218-12221
Small gold clusters (<1 nm), protected by monolayers of glutathione, N-(2-mercaptopropionyl)glycine, or mercaptosuccinic acid, were prepared by reducing the corresponding Au(I)-thiolate polymers and were fractionated by size using polyacrylamide gel electrophoresis (PAGE). Mass analysis of the fractionated clusters revealed that their core sizes varied with the molecular structures of the thiolates. This finding indicates that the reduction of the Au(I)-thiolate polymers yields small clusters whose growth is kinetically hindered by passivation with thiolates. Optical spectra of the clusters with identical compositions exhibited different profiles depending on the thiolate molecular structures. This observation implies that deformation of the underlying gold cores is induced by interligand interactions. 相似文献