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101.
Highly regio-selective cyanation of vicinal (Z)-dibromoalkenyl silanes was achieved by a vinylic Rosenmund-von Braun reaction, significantly suppressing side-production of alkyne. The alkyne was generated by a halogen elimination side-reaction that is an intrinsic problem in metal-activation of vicinal dihaloalkenes. We have studied to overcome the problem, and finally found the combination of CuCN and O = PPh3 in toluene solvent effectively controlled the production of byproducts. The resultant single isomer has significance in potentially application as a multi-tunable synthetic scaffold. 相似文献
102.
Hiroaki Aizawa Ken Hatano Hitoshi Saeki Nobuaki Honsho Tetsuo Koyama Koji Matsuoka Daiyo Terunuma 《Tetrahedron letters》2010,51(12):1545-6442
A new compound having a 2,3,4,5-tetraphenylsilole derivative on the center silicon of Dumbbell(1)6Gb3; Silole-Dumbbell(1)6Gb3 (1) was previously reported. It was found that 1 exhibited strongly increased fluorescence both in water and in a 96% acetone/water mixed solvent. The physical behavior of 1 in water and in the 96% acetone/water mixed solvent was investigated, and analyses including fluorescence quantum yields, dynamic-light-scattering (DLS), atomic-force-microscopy (AFM), and fluorescence microscopy were carried out. It was clarified that 1 dynamically formed different types of aggregates in water and in higher acetone concentrations to yield high aggregation-induced emission (AIE) effects due to the formation of micelle-like particles in water and inversion-type micelles in the acetone/water mixed solvent, respectively. 相似文献
103.
Evaluation of thermodynamic and kinetic stability of CuAlO<Subscript>2</Subscript> and CuGaO<Subscript>2</Subscript> 总被引:1,自引:0,他引:1
Yuh Kumekawa Motohiro Hirai Yuhki Kobayashi Satoshi Endoh Eri Oikawa Takuya Hashimoto 《Journal of Thermal Analysis and Calorimetry》2010,100(1):57-63
Thermodynamic and kinetic stabilities of CuAlO2 and CuGaO2 have been evaluated by using thermogravimetry and thermodynamic calculations. It has been revealed that CuAlO2 and CuGaO2 are not thermodynamically stable in air below 800 °C and 1,200 °C, respectively, and that the oxidation reaction, 4CuMO2 + O2 → 2CuO + 2CuM2O4 (M = Al, Ga), should occur if the reaction kinetics are high enough. However, rate constants and activation energies indicated
slow kinetics of the oxidation reaction, showing kinetic stability of CuMO2 even under some thermodynamically unstable temperatures and atmospheres. It was also concluded that CuAlO2 showed higher thermodynamic and kinetic stability than CuGaO2. 相似文献
104.
Atsushi Mineshige Yoshiki OhnishiRyuta Sakamoto Yusuke DaikoMasafumi Kobune Tetsuo YazawaHideki Yoshioka Takayuki NakaoTomokazu Fukutsuka Yoshiharu Uchimoto 《Solid State Ionics》2011,192(1):195-199
Electronic as well as ionic conducting properties for oxyapatite-type solid electrolytes based on lanthanum silicate, La9.333 + xSi6O26 + 1.5x (LSO) were investigated in the oxygen-excess region (x > ca. 0.3). We have found that the oxygen excess-type LSO (OE-LSO), namely La10Si6O27 on weighted basis, exhibited high conductivity, and substitution of the Si-site of LSO with some dopants (Mn+) had a positive effect toward the conducting property. Furthermore, it was also found that addition of a very small amount of iron ions into the M-doped OE-LSO, La10(Si6-yMn+y)O27-(2-0.5n)y, improved its conductivity. On the other hand, replacement of the La-site with various ions for La10(Si6-yMn+y)O27-(2-0.5n)y did little to improve conductivity. The electronic transport numbers for Al-doped OE-LSO with Fe-addition, (1-α){La10(Si5.8Al0.2)O26.9}-α(FeOγ), evaluated with the Hebb-Wagner polarization method were very low: i.e., 1.1 × 10− 3 and 2.9 × 10− 3 under P(O2) = 1.1 × 104 Pa at 1073 K for α = 0.00 and 0.005, respectively. Conductivity for each sample was unchanged under humidified atmosphere at 1073 K sustained for over 50 h, revealing that both compositions were chemically stable. It was concluded that 0.995{La10(Si5.8Al0.2)O26.9}-0.005(FeOγ) is suitable for the fuel cell electrolytes because of its high and almost pure ionic conductivity, and its good chemical stability under humidified as well as reducing conditions. 相似文献
105.
A wide class of Higgs sectors is investigated in supersymmetric standard models. When the lightest Higgs boson (h ) looks the standard model one, the mass (mh) and the triple Higgs boson coupling (the hhh coupling) are evaluated at the one-loop level in each model. While mh is at most 120–130 GeV in the minimal supersymmetric standard model (MSSM), that in models with an additional neutral singlet or triplet fields can be much larger. The hhh coupling can also be sensitive to the models: while in the MSSM the deviation from the standard model prediction is not significant, that can be 30–60% in some models such as the MSSM with the additional singlet or with extra doublets and charged singlets. These models are motivated by specific physics problems like the μ-problem, the neutrino mass, the scalar dark matter and so on. Therefore, when h is found at the CERN Large Hadron Collider, we can classify supersymmetric models by measuring mh and the hhh coupling accurately at future collider experiments. 相似文献
106.
Jing-Kun Fang De-Lie An Kan Wakamatsu Tetsuo Iwanaga Daisuke Matsuo Junzo Otera 《Tetrahedron letters》2010,51(6):917-6811
A series of diphenylamino-substituted phenylene-(poly)ethynylenes were successfully synthesized by a combination of Sonogashira coupling and double elimination protocol of β-substituted sulfones. When UV-light was irradiated, the amino-substituted phenylene-(poly)ethynylene emitted strong luminescence. The emission underwent a large bathochromic shift in polar solvent because of stabilization of their charge-separated excited states. Analyses of fluorescence life times of aminoacetylenes revealed that radiationless process was suppressed in the polar solvent CH2Cl2, resulting in high quantum yields. 相似文献
107.
108.
109.
Takahiro Nakae Ryuji Ohnishi Yoshiharu Kitahata Tatsuya Soukawa Hisako Sato Shigeki Mori Tetsuo Okujima Hidemitsu Uno Hiroshi Sakaguchi 《Tetrahedron letters》2012,53(13):1617-1619
6,13-Diiododibenzo[a,h]anthracene and 5,8-diiodopicene were synthesized by AuCl-catalyzed double cyclization. The highly selective reaction yielded a new class of peri-halogenated fused aromatics. 相似文献
110.
AbstractInteractions of glucopyranose, fructopyranose and sucrose with a proteinaceous receptor model have been examined to validate the stereomolecular mechanisms of sweet taste proposed for sugars. The methylene groups at C-6 of glucose, at C-1 and C-6 of fructose and at C-6, C-1' and C-6' of sucrose appear to play an important role as dispersive interaction centres with the receptor. 相似文献