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Isao Yamaguchi Hidetake Ishii Tatsuaki Sakano Kohtaro Osakada Takakazu Yamamoto 《应用有机金属化学》2001,15(3):197-203
1,1′‐Ferrocenedithiol reacts with di(4‐methoxyphenyl)silane, diphenylsilane, and di(4‐fluorophenyl)silane in the presence of RhCl(PPh3)3 catalyst to give mixtures of 2,2‐diaryl‐1,3‐dithia‐2‐sila[3]ferrocenophanes (1a–3a) and ? (Fc? S? SiAr2? S) n? (Fc = 1,1′‐ferrocenylene; 1b: Ar = C6H4OMe‐4; 2b: Ar = Ph; 3b: Ar = C6H4F‐4). The products are isolated and characterized by NMR spectroscopy and elemental analyses. The polymers 1b–3b, obtained from a toluene‐soluble fraction of the products, show GPC elution patterns corresponding to Mn values of 2700–4600 (polystyrene standards). The UV–vis spectra of the ferrocenophanes and polymers exhibit a d–d transition peak at about 440 nm, while the polymers show a π–π* transition peak at 320–330 nm. The cyclic voltammograms of 3a (Ar = C6H4F ? 4) and 3b show a reversible redox of the iron center at 0.27 V and 0.35 V (Ag+/Ag) respectively. Reaction of 1,1′‐ferrocenedimethanol with diphenylsilane in the presence of RuCl2(PPh3)3 catalyst results in selective formation of 3,3‐diphenyl‐2,4‐dioxa‐3‐sila[5]ferrocenophane ( 4 ), whose structure was determined by X‐ray crystallography. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
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Prof. Takanori Suzuki Yuto Sakano Dr. Tomohiro Iwai Dr. Shinichi Iwashita Dr. Youhei Miura Dr. Ryo Katoono Prof. Hidetoshi Kawai Prof. Kenshu Fujiwara Prof. Yasushi Tsuji Prof. Takanori Fukushima 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(1):117-123
When two benzene rings are fused to a tetraaryl‐o‐quinodimethane skeleton, sterically hindered helical molecules 1 acquire a high thermodynamic stability. Because the tetraarylbutadiene subunit contains electron‐donating alkoxy groups, 1 undergo reversible two‐electron oxidation to 2 2+, which can be isolated as deeply colored stable salts. Intramolecular transfer of the point chirality (e.g., sec‐butyl) on the aryl groups to helicity induces a diastereomeric preference in dications 2 b 2+ and 2 c 2+, which represents an efficient method for enhancing circular‐dichroism signals. Thus, those redox pairs can serve as new electrochiroptical response systems. X‐ray analysis of dication 2 2+ revealed π–π stacking interaction of the diarylmethylium moieties, which is also present in solution. The stacking geometry is the key contributor to the chirosolvatochromic response. 相似文献
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Akira Ishikawa Tomoyuki Ohno Shinji Sakano Yoshihiro Shiroishi 《Journal of magnetism and magnetic materials》1993,120(1-3):357-361
The magnetic properties and crystalline structure of Co alloy film deposited on a regularly corrugated substrate have been studied. Microscopic grooves are lithographically fabricated on InP substrates. In-plane anisotropy energy is 4–5×104J/m3. The magnetic anisotropy is affected by the crystallographic orientation and the microscopic shape of the corrugated Co alloy film. 相似文献
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Tatsunori Sakano Hiroki Fukuoka Yoshihiro Yata Toshiharu Saiki Minoru Obara 《Applied Physics A: Materials Science & Processing》2008,93(3):697-703
We employed epi-GaN substrates for ZnO film growth, and studied the deposition and post-annealing effects. ZnO films were
grown by pulsed laser deposition (PLD) method. The as-grown films were annealed for one hour under atmospheric pressure air.
ZnO morphologies after annealing were investigated and the post-annealed ZnO films grown at T
g
=700oC have very smooth surfaces and the rms with roughness is about 0.5 nm. Finally, ZnO post-annealed buffer layer was inserted
between ZnO epilayer and GaN/sapphire substrates. It is confirmed by AFM that growth temperature of 700oC helps the films grow in step-flow growth mode. It is observed by cathode luminescence spectrum that the ZnO film grown at
700oC has very low visible luminescence, indicating the decrease of the deep level defects. It is also revealed by Hall measurements
that carrier concentration is decreased by increasing the growth temperatures. It is suggested that low temperature buffer
layer growth and post-annealing technique can be used to fabricate ZnO hetero-epitaxy. 相似文献
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Anti-allergic effect of the flavonoid myricitrin from Myrica rubra leaf extracts in vitro and in vivo 总被引:1,自引:0,他引:1
Flavonoids are ingested by the general population as anti-oxidant and anti-inflammatory agents. In this study, we investigated the effects of myricitrin, a flavonoid rich in Myrica rubra leaf, upon anti-inflammatory action. Myrica rubra leaf extracts inhibited pro-inflammatory TNFα production in a macrophage cell line, Raw264.7 cells. We observed that the serum IgE levels in the leaf extract-treated DO11.10, a mouse allergy model, were down-regulated. HPLC was performed to demonstrate that M. rubra leaf extracts contain a large amount of myricitrin. We observed an inhibitory effect of HPLC-purified myricitrin on TNFα production in Raw264.7 cells. Thus, myricitrin may be of potential interest in the management of inflammatory conditions. 相似文献
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Yamauchi Y Sekiguchi K Chida K Arakawa T Nakamura S Kobayashi K Ono T Fujii T Sakano R 《Physical review letters》2011,106(17):176601
We measure the current and shot noise in a quantum dot in the Kondo regime to address the nonequilibrium properties of the Kondo effect. By systematically tuning the temperature and gate voltages to define the level positions in the quantum dot, we observe an enhancement of the shot noise as temperature decreases below the Kondo temperature, which indicates that the two-particle scattering process grows as the Kondo state evolves. Below the Kondo temperature, the Fano factor defined at finite temperature is found to exceed the expected value of unity from the noninteracting model, reaching 1.8±0.2. 相似文献
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Alexandru Dimca Fayçal Maaref Claude Sabbah Morihiko Saito 《Mathematische Annalen》2000,318(1):107-125
Using local cohomology and algebraic -Modules, we generalize a comparison theorem between relative de Rham cohomology and Dwork cohomology due to N. Katz, P. Monsky,
A. Adolphson and S. Sperber.
Received June 10, 1999 / Published online July 20, 2000 相似文献