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11.
Kaoru Nakajima Shinichi Oshima Motofumi Suzuki Kenji Kimura 《Surface science》2012,606(21-22):1693-1699
Surface structures of equimolar mixtures of imidazolium-based ionic liquids (ILs) having a common cation (1-butyl-3-methylimidazolium ([C4MIM]) or 1-hexyl-3-methylimidazolium ([C6MIM])) and different anions (bis(trifluoromethanesulfonyl)imide ([TFSI]), hexafluorophosphate ([PF6]) or chlorine) are studied using high-resolution Rutherford backscattering spectroscopy (HRBS). Both cations and anions have the same preferential orientations at the surface as in the pure ILs. In the mixture, the larger anion is located shallower than the smaller anion. The [TFSI] anion is slightly enriched at the surface relative to [PF6] with coverage of ~ 60% for the equimolar mixtures of [C4(6)MIM] [TFSI] and [C4(6)MIM] [PF6]. No surface segregation is observed for [C6MIM] [TFSI]0.5[Cl]0.5 and [C6MIM] [PF6]0.5[Cl]0.5. These results are different from the recent TOF-SIMS measurement where very strong surface segregation of [TFSI] was concluded for the mixture of [C4MIM] [TFSI] and [C4MIM] [PF6]. 相似文献
12.
Photo-induced enhancement of charge density wave current in the quasi-one-dimensional conductor TaS3
In the near vicinity of Peierls transition temperature TP, we have measured the V-I characteristics of the quasi-one-dimensional conductor TaS3 under dark and photo-irradiation conditions. It is found that a significant enhancement of CDW current occurs only around the threshold voltage Vt under photo-irradiation. This effect can be interpreted as a result of screening of pinning potential for CDW condensate by photo-excited quasi-particles (QP's). Further the distribution of pinning potential intensity is reflected in the behavior of V-I characteristics near Vt. Our finding suggests that the strength of pinning potential can be controlled by the photo-excited QP's in quasi-1D conductors. 相似文献
13.
Hiroyuki Ishibashi Motofumi Okada Kyoko Iida Masazumi Ikeda 《Journal of heterocyclic chemistry》1985,22(6):1527-1529
A variety of ethyl isothiochroman-1-carboxylates and related compounds were synthesized by treatment of 2-chloro-2-[(2-arenyl)ethylthio]acetates with stannic chloride in methylene chloride. The same procedure was applied to the synthesis of ethyl 4-chloro-4-methyltetrahydrothiopyran-2-carboxylate. Some isothiochroman-1-carboxylic acids were prepared and evaluated for antiinflammatory activity. Among the compounds tested, 7-phenoxyisothiochroman-1-carboxylic acid showed weak activity. 相似文献
14.
Ultrafast photosynthetic reduction of elemental sulfur by Au nanoparticle-loaded TiO2 总被引:1,自引:0,他引:1
Kiyonaga T Mitsui T Torikoshi M Takekawa M Soejima T Tada H 《The journal of physical chemistry. B》2006,110(22):10771-10778
Nanometer-sized gold particles with varying mean size from 3.2 to 12.2 nm were loaded on the surfaces of TiO2 particles in a highly dispersed state with the loading amount maintained constant (0.46 +/- 0.02 mass %) using the deposition-precipitation method. Light irradiation (lambda(ex) > 300 nm) to a deaerated ethanol TiO2 particle suspension containing elemental sulfur (S8) led to the energetically uphill reduction of S8 to H2S. It has been found that this reaction is dramatically enhanced with such a low level of Au loading on TiO2 and that the zero-order rate constant of reaction increases with decreasing mean size of Au nanoparticles (d). The effects of reaction parameters (substrate concentration, light intensity, temperature) on the rate of reaction were studied to infer the essential reaction mechanism. Further, a kinetic analysis has led to a conclusion that the increase in the rate of reaction with decreasing d results from the improvement of the charge separation efficiency. 相似文献
15.
Hikaru Aramoto Motofumi Osaki Subaru Konishi Chiharu Ueda Yuichiro Kobayashi Yoshinori Takashima Akira Harada Hiroyasu Yamaguchi 《Chemical science》2020,11(17):4322
Stimuli-responsive hydrogels have attracted attention as soft actuators that act similarly to muscles. In this work, hydrogel actuators controlled by host–guest interactions have been developed. The introduction of a 1:1 inclusion complex into a hydrogel is a popular design for achieving a change in cross-linking density. To realize faster and larger deformation properties, the introduction of a 1:2 inclusion complex is effective because the alteration in cross-linking density in a hydrogel with 1:2 complexes is larger than that in a hydrogel with 1:1 complexes. A redox-responsive hydrogel actuator cross-linked with 1:2 inclusion complexes is designed, where γ-cyclodextrin (γCD) and viologens modified with an alkyl chain derivative (VC11) were employed as the host and guest units, respectively. γCD includes two VC11 molecules in its cavity. The obtained γCD–VC11 hydrogel cross-linked with the 1:2 complex showed faster and larger deformation behaviour than the αCD–VC11 and the βCD–VC11 hydrogels cross-linked with a 1:1 complex. The deformation ratio and response speed of the γCD–VC11 hydrogel, which forms a supramolecular cross-linking structure by stimuli, are 3 and 11 times larger, respectively, than those of our previous hydrogel consisting of a βCD/ferrocene 1:1 inclusion complex.A hydrogel actuator with a 1:2 host–guest complex controlled by redox stimuli has been developed to realize faster and larger deformation. 相似文献
16.
Osaki M Takashima Y Yamaguchi H Harada A 《Journal of the American Chemical Society》2007,129(46):14452-14457
Poly-pseudo-rotaxanes CDs contains as a subset 1 (CDs; cyclodextrins, 1; poly(delta-valerolactone) having single beta-CD at the end of the polymer chain) initiate polymerization of delta-valerolactone (delta-VL) in the solid state when CDs (alpha-CD, beta-CD, and 2,6-di-O-methyl-beta-CD) are threaded onto the polymer chain. 1 without threaded CDs did not show any polymerization ability for delta-VL. An adamantane molecule (Ad) inhibited the polymerization ability of CDs contains as a subset 1 for delta-VL, indicating that beta-CD at the end of CDs contains as a subset 1 could not bind delta-VL because the beta-CD cavity was occupied by Ad. It should be noted that the insertion reaction and the polymerization took place inside the beta-CD cavity at the end of CDs contains as a subset 1 and that the formation of poly-pseudo-rotaxane is necessary for the initiation of delta-VL. The structures of beta-CD contains as a subset 1 and 1 were characterized by powder X-ray diffraction measurements and solid-state NMR spectroscopies. The polymer chain of beta-CD contains as a subset 1 was found to elongate in the solid state, whereas the polymer chain of 1 formed a random coil conformation. 1 was deactivated for the polymerization by blocking the active cavity of beta-CD with the polymer chain. CDs threaded onto 1 are immune to the initiation of delta-VL directly but have an essential role to fold the polymer chain in a proper way as an artificial chaperone. 相似文献
17.
Morimoto T Suzuki K Torikoshi M Kawahara T Tada H 《Chemical communications (Cambridge, England)》2007,(41):4291-4293
Micrometer-sized Ag(core)-AgCl(shell) composite crystals have been formed on TiO2 thin films by a two-st epelectrochemical method to provide information on the thermodynamic condition for efficient photoinduced interfacial electron transfer. 相似文献
18.
Jiro Suzuki Motofumi Furuya Minobu Iinuma Atsushi Takano Yushu Matsushita 《Journal of Polymer Science.Polymer Physics》2002,40(11):1135-1141
Morphological variations of ABC triblock copolymers through the blending of B or A/C homopolymers, all with short chain lengths, were studied experimentally. The samples were symmetric ISP triblock copolymers, where I, S, and P denote polyisoprene, polystyrene, and poly(2‐vinylpyridine), and component homopolymers. Microphase‐separated structures of the solvent‐cast films were observed with transmission electron microscopy and small‐angle X‐ray scattering. For an ISP/S system, the lattice constant of the tricontinuous gyroid structure (G‐structure) increased with an increase in the volume fraction of S (?s) if the amount of added homopolymer was small, but it reached a certain limit, reflecting the fact that the midblock chain had a limit for chain stretching. For I/ISP/P blends, on the contrary, the lattice constant of the G‐structure continued increasing with decreasing ?s. This result shows that the I and P domains did not have a limit for chain stretching because the two end blocks had free ends. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 1135–1141, 2002 相似文献
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Daijiro Kobayashi Motofumi Miura Masaharu Toriyama Shigeyasu Motohashi 《Tetrahedron letters》2019,60(2):120-123
The synthesis of optically active secondary and tertiary propargylic alcohols was accomplished by addition of lithium acetylide to chiral β-sulfinyl enones. Only a stoichiometric amount of the lithium acetylide was required and various substituents were tolerated. This reaction could be applied to substrates consisting of both ketones and aldehydes in high yields and excellent diastereoselectivities. 相似文献