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101.
Wei Zhou Soya Inoue Takashi Iwahashi Kaname Kanai Kazuhiko Seki Takayuki Miyamae Doseok Kim Yasushi Katayama Yukio Ouchi 《Electrochemistry communications》2010,12(5):672-675
The electrochemical interface between a polycrystalline Pt electrode and the ionic liquid 1-butyl-3-methylimidazolium trifluoromethanesulfonate ([bmim][OTf]) has been studied by in-situ IR-visible sum-frequency generation (SFG) spectroscopy. Potential dependent adsorption/desorption processes of OTf anions has been monitored within the electrochemical window. SFG results indicate that the ions form a double layer structure at the interface. Significant adsorption/desorption hysteresis has been observed for the anions on the Pt surface. 相似文献
102.
Anion configuration at the air/liquid interface of ionic liquid [bmim]OTf studied by sum-frequency generation spectroscopy 总被引:1,自引:0,他引:1
Iwahashi T Miyamae T Kanai K Seki K Kim D Ouchi Y 《The journal of physical chemistry. B》2008,112(38):11936-11941
The air/liquid interface of a room temperature ionic liquid, 1-butyl-3-methylimidazolium trifluoromethanesulfonate ([bmim]OTf), is investigated using infrared-visible sum frequency generation (SFG) spectroscopy. The SFG spectra clearly show low-frequency modes [CF 3-symmetric stretching (ss) mode and SO 3-symmetric stretching (ss) mode] of the OTf anion, demonstrating the existence of anions polar oriented at the interface. The amplitude of the CF 3-ss peak of the OTf anion has the opposite sign with respect to that of the SO 3-ss peak, indicating that OTf anions at the surface have polar ordering where the nonpolar CF 3 group points away from the bulk into the air, whereas the SO 3 group points toward the bulk liquid. The line width of the SFG peak from the submerged SO 3 group is appreciably narrower than that from IR absorption, suggesting the environment of the surface OTf anions is much more homogeneous than that of the bulk. The vibrational calculations also suggest that the anions and the cations form a more specific aggregated configuration at the surface as compared to the bulk. 相似文献
103.
S. Imamura T. Kitao H. Kanai S. Shono K. Utani H. Jindai 《Reaction Kinetics and Catalysis Letters》1997,61(1):201-207
N2O was decomposed over Rh supported on NaY zeolite and ZSM5. With low Rh-loading (≤0.1 wt.%) the activity of Rh was much higher
than that supported on SiO2 and CeO2. On the contrary, the activity of Rh-loaded zeolites (0.1 wt.%) was not so high or even lower than that on SiO2 for the oxidation of toluene, which has a larger molecular size than N2O. Thus the Rh present inside the zeolite cavity was especially effective in the decomposition of N2O. 相似文献
104.
Regioselective generation of the C(2)-carbocation a of tricyclo[4.2.2.01,5]decane ( 1 ) by treatment of both corresponding epimeric alcohols 5 and 6 with BF3 and trapping the rearranged tricyclo[5.3.0.04,8]decan-7-yl carbocation b with Et3SiH as hydride-ion donor (ionic hydrogenation) gives the corresponding hydrocarbon 3 as sole product in almost quantitative yield. The latter is a known intermediate in the Lewis-acid-catalyzed rearrangement of 1 to adamantane ( 4 ). 相似文献
105.
Olefin Recovery by *BEA-Type Zeolite Membrane: Affinity-Based Separation with Olefin−Ag+ Interaction
Dr. Motomu Sakai Yuto Tsuzuki Naoyuki Fujimaki Prof. Masahiko Matsukata 《化学:亚洲杂志》2021,16(9):1101-1105
Ag+ was introduced into *BEA-type zeolite membrane by an ion-exchange method to enhance olefin selectivity. Ag−*BEA membrane exhibited superior olefin separation performance for both ethylene/ethane and propylene/propane mixtures. Particularly, the separation factor for ethylene at 373 K reached 57 with the ethylene permeance of 1.6×10−7 mol m−2 s−1 Pa−1. Adsorption properties of olefin and paraffin were evaluated to discuss contribution of Ag+ to separation performance enhancement. A strong interaction between olefin and Ag+ in the membrane caused preferential adsorption of olefin against paraffin, leading to selective permeation of olefin. Ag−*BEA membrane also exhibited high olefin selectivities from olefin/N2 mixtures. The affinity-based separation through Ag−*BEA membrane showed a high potential for olefin recovery and purification from various gas mixtures. 相似文献
106.
M Takamura K Funabashi M Kanai M Shibasaki 《Journal of the American Chemical Society》2001,123(28):6801-6808
Full details of the first catalytic enantioselective Reissert-type reaction are described. Utilizing the Lewis acid-Lewis base bifunctional catalyst 5 or 6 (9 mol %), the Reissert products were obtained in 57 to 99% yield with 54 to 96% ee. Electron-rich quinolines produced better yields and enantioselectivities than electron-deficient substrates. Kinetic studies indicated that the reaction should proceed via the rate-determining acyl quinolinium formation, followed by the attack of a cyanide. The catalyst does not facilitate the first rate-determining step; however, it strongly facilitates the second cyanation step. The reaction was successfully applied to an efficient catalytic asymmetric synthesis of a potent NMDA receptor antagonist (-)-L-689,560. A key step is the one-pot process using the Reissert-type reaction from quinoline 1f, followed by stereoselective reduction of the resulting enamine 2f. This step gave the key intermediate 20 in 91% yield with 93% ee, using 1 mol % of 6. The enantiomerically pure target compound was obtained through 10 operations (including recrystallization) in total yield of 47%. Furthermore, 6 was immobilized to JandaJEL, and the resulting solid-supported catalyst 11 afforded 20 in a comparable yield to the homogeneous 6, but with slightly lower enantioselectivity. 相似文献
107.
108.
Diffraction patterns of wedges are studied with special attention to the finish of the samples. We assume that the sharply finished vertex should generate two hemispherical waves by the end effect of the cylindrical waves issued from two sides of the wedge under illumination of the coherent light. It is found that the assumption is valuable to the investigation of the diffraction pattern appearing in the shadow region of the wedge. 相似文献
109.
Kaname Kanai Kouki Akaike Kiichirou Koyasu Kentaro Sakai Toshio Nishi Yasunori Kamizuru Tatsuhiko Nishi Yukio Ouchi Kazuhiko Seki 《Applied Physics A: Materials Science & Processing》2009,95(1):309-313
The unoccupied π
* states of the solid film of electron accepting organic molecules, 7,7,8,8-tetracyanoquinodimethane (TCNQ), fluorinated TCNQ
derivatives, 11,11,12,12-tetracyanonaphtho-2,6-quinodimethane (TNAP), C60, and 6,6-phenyl-C61-butyric acid methyl ester (PCBM) have been studied by inverse photoemission spectroscopy. The assignment of the π
* affinity levels of these typical electron accepting molecules provides the basic information for the organic electronics
and the new electronic functional molecular design. The comparison with density functional theory calculations enables understanding
how the electron affinity evolves in terms of molecular orbitals. The correlation between the film morphology and the irradiation
damage on the TCNQ derivative samples by electron impact during the inverse photoemission measurements is also discussed. 相似文献
110.
Gelation of colloidal crystals without degradation in their transmission quality and chemical tuning
Toyotama A Kanai T Sawada T Yamanaka J Ito K Kitamura K 《Langmuir : the ACS journal of surfaces and colloids》2005,21(23):10268-10270
A single-domain colloidal crystal with high transmission quality, prepared by a shear-induced process, was fixed as a hydrogel film by photopolymerization. Upon gelation, the original optical quality was almost perfectly preserved. By replacing the solvent, the gelled crystal could be converted to smaller lattice constant crystals without significant degradation in its transmission characteristics. The conversion results in a stop-band wavelength coverage across the entire visible light range. 相似文献