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101.
Takaya Terashima Makoto Ouchi Tsuyoshi Ando Masami Kamigaito Mitsuo Sawamoto 《Journal of polymer science. Part A, Polymer chemistry》2006,44(17):4966-4980
One-pot, spontaneous, and in-situ incorporation of Ru(II) complexes into a microgel (solubilized nanometer-scale network) has been achieved in near quantitative efficiency by a polymer-linking reaction of linear living poly(methyl methacrylate) (PMMA) with a bifunctional methacrylate (ethylene glycol dimethacrylate or bisphenol A dimethacrylate; linking agent) and a phosphine-ligand monomer [diphenyl-4-styryl-phosphine ( 3 ); i.e., CH2CH C6H4 p-PPh2] in the RuCl2(PPh3)3-catalyzed living radical polymerization. The products were Ru-bearing. PMMA-armed star polymers with a microgel-core that consisted of a copolymer network of the linking agent and 3 . Upon the network formation, the phosphine ligands efficiently encapsulated RuCl2(PPh3)3, thus achieving a polymer catalyst directly from a polymerization catalyst. Colored dark brown-red, the star polymers exhibited UV-vis absorptions originating from the entrapped complex (3.1–7.4 × 10−5 mol Ru/g of polymer), the incorporation efficiency being close to 100% with respect to the original polymerization-catalyst. Detailed spectroscopic characterization showed the following: an absolute molecular weight of 1.7 × 105 to 1.7 × 106, an arm number of 11–92 arms/polymer, and a radius of gyration of 8–19 nm (in DMF). Direct observation of the individual star molecules in solid state was achieved by transmission electron microscopy (unstained; 2–3 nm dark dots for the core) and atomic force microscopy (semi-circular images). © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4966–4980, 2006 相似文献
102.
Satoh T Sato T Kubo A Tamura J 《Journal of the American Society for Mass Spectrometry》2011,22(5):797-803
In this study, we have developed a tandem time-of-flight mass spectrometry (TOF/TOF) technique involving the use of a matrix-assisted
laser desorption/ionization ion source that exhibits high precursor ion selectivity. An ion optical system with a 17 m spiral
ion trajectory was used in the first time-of-flight mass spectrometer. High precursor ion selectivity was achieved by realizing
a 15 m flight path, which is considerably longer than that of the conventional MALDI-TOF/TOF before the precursor ion selection
by an ion gate; monoisotopic ions could be selected properly up to m/z 2500. Furthermore, the first time-of-flight mass spectrometer was composed of electrostatic sectors and could eliminate post-source
decay (PSD) ions. Precursor ions with 20 keV kinetic energy were selected and injected into a collision cell, leading to the
generation of fragment ions by high-energy collision-induced dissociation (HE-CID). The optimized second time-of-flight mass
spectrometer included a post-acceleration region and an offset parabolic reflectron to record product ion spectra in the entire
mass range. Our system could generate a simple HE-CID product ion spectrum because each fragment pathway could be observed
as a single peak by the selection of monoisotopic ions of all precursor ions and HE-CID fragment pathways could be predominantly
observed by the PSD ion elimination. 相似文献
103.
An efficient one-to-one coupling reaction of atmospheric pressure carbon dioxide with 1,3-dienes is realized for the first time through PSiP-pincer type palladium-catalyzed hydrocarboxylation. The reaction is applicable to various 1,3-dienes including easily available chemical feedstock such as 1,3-butadiene and isoprene. This protocol affords a highly useful method for the synthesis of β,γ-unsaturated carboxylic acid derivatives from CO(2). 相似文献
104.
Single-chain folding of polymers for catalytic systems in water 总被引:1,自引:0,他引:1
Terashima T Mes T De Greef TF Gillissen MA Besenius P Palmans AR Meijer EW 《Journal of the American Chemical Society》2011,133(13):4742-4745
Enzymes are a source of inspiration for chemists attempting to create versatile synthetic catalysts. In order to arrive at a polymeric chain carrying catalytic units separated spatially, it is a prerequisite to fold these polymers in water into well-defined compartmentalized architectures thus creating a catalytic core. Herein, we report the synthesis, physical properties, and catalytic activity of a water-soluble segmented terpolymer in which a helical structure in the apolar core is created around a ruthenium-based catalyst. The supramolecular chirality of this catalytic system is the result of the self-assembly of benzene-1,3,5-tricarboxamide side chains, while the catalyst arises from the sequential ruthenium-catalyzed living radical polymerization of the different monomers followed by ligand exchange. The polymers exhibit a two-state folding process and show transfer hydrogenation in water. 相似文献
105.
Ko Mibu Makoto Seto Takaya Mitsui Yoshitaka Yoda Ryo Masuda Shinji Kitao Yasuhiro Kobayashi Edi Suharyadi Masaaki Tanaka Masakiyo Tsunoda Hideto Yanagihara Eiji Kita 《Hyperfine Interactions》2013,217(1-3):127-135
Applications of synchrotron-radiation-based Mössbauer spectroscopy in the “energy domain” to the studies on magnetism of thin films are introduced on the basis of the experiments recently performed at SPring-8, Japan. The measured samples are spintronics-related thin films, such as Co2MnSn films, layered Fe/Cr films, layered Fe/Fe3O4 films, and Fe4N films. The validity of the energy domain measurements is demonstrated in the light of industrial applications of magnetic thin films. 相似文献
106.
Susan K. Kozawa Kazuma Matsumoto Ayaka Suzuki Mitsuo Sawamoto Takaya Terashima 《Journal of polymer science. Part A, Polymer chemistry》2019,57(3):313-321
Self‐assembly of amphiphilic ABA random triblock copolymers in water serves as a novel approach to create unique structure micelles connected with flexible linkages. The ABA triblock copolymers consist of amphiphilic random copolymers bearing hydrophilic poly(ethylene glycol) and hydrophobic dodecyl pendants as the A segments and a hydrophilic poly(ethylene oxide) (PEO) as the middle B segment. The A block is varied in dodecyl methacrylate content of 20%–50% and degree of polymerization (DP) of 100‐200. By controlling the composition and DP of the A block, various architectures can be tailor‐made as micelles in water: PEO‐linked double core unimer micelles, PEO‐looped unimer or dimer micelles, and multichain micelles. Those PEO‐linked or looped micelles further exhibit thermoresponsive solubility in water. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 313–321 相似文献
107.
108.
The mechanism behind cavity-induced pressure oscillations in supersonic flows past a deep rectangular cavity is not well understood despite several investigations having been carried out. In particular, the process by which the pressure wave is generated and the path of the pressure wave propagating inside the cavity remains unclear. In the present study, the pressure waves around a deep rectangular cavity over which nitrogen gas flows at a Mach number of 1.7 are visualized using the schlieren method. The length of the cavity is 14.0?mm. The depths of the cavity are selected as 20.0?and 11.7?mm, corresponding to length-to-depth ratios of 0.70 and 1.2, respectively. The pressure waves propagating inside as well as outside the cavity have been successfully visualized using a high-speed camera, and the propagation pattern of these waves is found to be different from that previously predicted by numerical simulation and from those expected in previous oscillation models. In addition, the pressure oscillation near the trailing edge of the cavity is also measured using semiconductor-type pressure transducers simultaneously with the capture of the schlieren images. As a result, the relationship between the shear-layer motion, pressure-wave generation, and pressure oscillation at the trailing edge of the cavity is clarified experimentally. 相似文献
109.
In a recent article (Konno and Yamamoto in ISE 07-01, Department of Industrial and Systems Engineering, Chuo University, February
2007), one of the authors formulated the problem of choosing the best set of explanatory variables from a large number of candidate
variables in a linear regression model as a mixed 0–1 integer linear programming problem and showed that it can be solved
by the state-of-the-art integer programming software. 相似文献
110.
Narumasa Saito Jun Takaya Nobuharu Iwasawa 《Angewandte Chemie (International ed. in English)》2019,58(29):9998-10002
Iridium complexes having a pincer‐type gallylene ligand were successfully synthesized utilizing bis(phosphino)terpyridine as an efficient scaffold for the Ir?GaI bond. The stabilization of the gallylene moiety by the pincer‐type structure enabled various reactions at Ir with keeping the gallylene ligand intact, leading to unique structures and reactivities of PGaIP?Ir complexes. 相似文献