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281.
[structure: see text] The ferrocene receptor bearing the podand dipeptide chains (-l-Ala-l-Pro-NHPyMe) was found to provide a chirality-organized binding site through two intramolecular interchain hydrogen bonds between CO (Ala) and NH (another Ala) of each podand dipeptide chain. The size-selective and chiral recognition of dicarboxylic acids was achieved by multipoint hydrogen bonds of the binding site. 相似文献
282.
Takanobu Hino Shigeko Nakanishi Tsuneaki Maeda Toshiyuki Hobo 《Journal of chromatography. A》1998,810(1-2):141-147
An injection method for a large amount of headspace gas which enables determination of trace amounts of very volatile organic compounds (VVOCs), dichlorodifluoromethane, chloromethane, vinyl chloride, bromomethane, chloroethane and trichlorofluoromethane in all kinds of environmental water was developed. A gas phase equilibrated with the water phase in a vial was purged with helium for a short time. The VVOCs were then introduced into a trapping tube packed with Tenax TA, which had been cooled using carbon dioxide. After trapping, the VVOCs were thermally desorbed and put into a GC–MS system for subsequent analysis. This method is applicable to various types of samples. 相似文献
283.
Katsuhiko Shinyama Yasuyuki Harada Reizo Maeda Hiroshi Nakamura Shigeki Matsuta Toshiyuki Nohma Ikuo Yonezu 《Research on Chemical Intermediates》2006,32(5):447-452
The effects of separators on the self-discharge behavior and the suppression of self-discharge by a sulfonated polyolefin
separator were investigated with test cells. The experimental results indicate that a sulfonated polyolefin separator effectively
suppresses the self-discharge reaction in nickel-metal hydride batteries. It is also found that a sulfonated polyolefin sheet
does not necessarily need to be sandwiched by positive and negative electrodes to act as a separator; it can be placed anywhere
within a cell to suppress the self-discharge reaction. The self-discharge reaction is considered to be suppressed by trapping
redox shuttle substances, especially nitrogen-containing compounds, by the separator. 相似文献
284.
285.
A novel neutral glycosphingolipid found in Microcosmus sulcatus containing a β-d-Galp(1→4)[α-d-Fucp-(1→3)]β-d-Glcp-(1→)Cer motif was synthesized. Trisaccharide derivatives were synthesized using trimethylsilyltrifluoromethanesulfanate (TMSOTf) and N-iodosuccimide (NIS)/trifluoromethane sulfonic acid (TfOH) as the promoters. Synthesis was achieved with an efficient one-pot glycosylation strategy. This is the first report of a one-pot glycosylation strategy using the procedure of Boons et al. for the synthesis of a natural product. Coupling of trisaccharide derivative 19 and ceramide derivative 20 by TMSOTf afforded the glycosphingolipid derivative 21. The fully protected glycoside was deprotected to give the target glycosphingolipid 2. 相似文献
286.
287.
Preparation of ureido group bearing polymers and their upper critical solution temperature in water
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Ami Fujihara Kohei Itsuki Naohiko Shimada Atsushi Maruyama Naoya Sagawa Toshiyuki Shikata Shin‐Ichi Yusa 《Journal of polymer science. Part A, Polymer chemistry》2016,54(18):2845-2854
Poly(2‐ureidoethylmethacrylate) (PUEMn) was synthesized via reversible addition‐fragmentation chain transfer (RAFT) radical polymerization and following polymer reaction. We prepared two PUEMn samples with different degrees of polymerization (n = 100 and 49). The polymers exhibited upper critical solution temperature (UCST) in phosphate‐buffered saline (PBS) solution. The phase separation temperature (Tp) in PBS can be controlled ranging from 17 to 55 °C by changing molecular weight of the polymer, polymer concentration, and adding NaCl concentration. The polymers in PBS formed coacervate drops by liquid–liquid phase separations below Tp. Results of the dielectric relaxation measurement, the hydration number per monomeric unit was 5 above Tp. Based on a fluorescence study, the polymer formed slightly hydrophobic environments below Tp. The liquid–liquid phase separation was occurred presumably because of weak hydrophobic interactions and intermolecularly hydrogen bonding interactions between the pendant ureido groups. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 2845–2854 相似文献
288.
289.
Atsuhiro Nabei Takayoshi Kuroda-Sowa Toshiyuki Shimizu Takashi Okubo Masahiko Maekawa Megumu Munakata 《Polyhedron》2009,28(9-10):1734-1739
The preparation and magnetic properties of three Fe(II)–bis-Schiff base complexes, [Fe2(L1)2(4,4′-bpy)] · MeOH (1), [Fe(L2)(EtOH)] (2) and [Fe(L3)(MeOH)] (3) (L1 = N,N′-bis(2-hydroxy-1-naphthaldehyde)-1,2-phenylenediimine; L2 = N,N′-bis(salicylidene)-1,2-phenylenediamine; L3 = N,N′-bis(5-Cl-salicylidene)-1,2-phenylenediamine; 4,4′-bpy = 4,4′-bipyridine) are reported. X-ray single crystal structure analyses for 1–3 reveal that 1 shows a dinuclear Fe(II)–bis-Schiff base complex bridged by 4,4′-bpy, while 2 and 3 show mononuclear structures. Molecular packing of 2 shows a uniform one-dimensional chain structure through hydrogen bonds and Fe?π interaction and that of 3 indicates significant π–π interaction to form a dimmer structure. The χT–T plots of 1–3 show all ferromagnetic interaction at low temperature. The origin of the ferromagnetic interaction observed in 2 is tentatively ascribed to the dimer formation through Fe?π interaction at low temperature. 相似文献
290.
Takeshi Ito Tetsuya Hiroi Satoru Kaneko Toshiyuki Ohsawa Kunio Matsumoto 《Talanta》2009,77(3):1185-712
We designed and prepared a micro biosensing system consisting of a flow through system with a sub-micro liter injection valve and a sub-micro liter volume bioreactor. An electrochemical detector was combined with the reactor for immediate detections. The volumes of the reactor and the sample loop for the injection were 850 nl and 320 nl, respectively. This paper described about the characteristics of the sensing system in the case of histamine detection for food analysis. Histamine oxidase from KAIT-B-007 was prepared by using a gene recombination technique and they were immobilized with chitosan beads (? = 70-105 μm). The detection less than one minute after injection made possible fast analysis for histamine. The biosensing system also showed a high performance for histamine detection in wide range of 1 μM-1 mM. In addition, we practically measured histamine content in raw tuna stored at room temperature and 35 °C up to 96 h. As a result of the comparison between our sensing system and HPLC method, there was good agreement. These results show that our microfluidic biosensing system has the potential to assist miniaturization with small sample volume and short determination time for a sequential food analysis. 相似文献