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61.
Neya S Imai K Hori H Ishikawa H Ishimori K Okuno D Nagatomo S Hoshino T Hata M Funasaki N 《Inorganic chemistry》2003,42(5):1456-1461
The iron complex of hemiporphycene, a molecular hybrid of porphyrin with porphycene, was incorporated into the apomyoglobin pocket to examine ligand binding ability of the iron atom in the novel porphyrinoid. Apomyoglobin was successfully coupled with a stoichiometric amount of ferric hemiporphycene to afford the reconstituted myoglobin equipped with the iron coordination structure of native protein. Cyanide, imidazole, and fluoride coordinated to the ferric protein with affinities comparable with those for native myoglobin. The ferrous myoglobin was functionally active to bind O(2) and CO reversibly at pH 7.4 and 20 degrees C. The O(2) affinity is 12-fold higher than that of native myoglobin while the CO affinity is slightly lower, suggesting decreased discrimination between O(2) and CO in the heme pocket. The functional anomaly was interpreted to reflect increased sigma-bonding character in the Fe(II)-O(2) bond. In contrast with 6-coordinate native NO protein, the NO myoglobin containing ferrous hemiporphycene is in a mixed 5- and 6-coordinate state. This observation suggests that the in-plane configuration of the iron atom in hemiporphycene is destabilized by NO. Influence of the core deformation was also detected with both the infrared absorption for the ferrous CO derivative and electron paramagnetic resonance for ferric imidazole complex. Anomalies in the ferric and ferrous derivatives were ascribed to the modified iron-N(pyrrole) interactions in the asymmetric metallo core of hemiporphycene. 相似文献
62.
Yoshio Imai Mitsuru Ueda Motokazu Ishimori 《Journal of polymer science. Part A, Polymer chemistry》1975,13(9):1969-1977
Novel polybenzamide-ureas have been synthesized by the polymerization of N-mesyloxyphthalimide with diamines in N-methyl-2-pyrrolidone in the presence of acid acceptors. The polymerization probably proceeds through the formation of ring-opened adducts, followed by elimination and rearrangement yielding 2-isocyanatobenzamide derivatives, which were subsequently reacted to give polybenzamide-ureas. These polymers had inherent viscosities of 0.12–0.34 and were soluble in a wide range of solvents, including pyridine and m-cresol, as well as polar aprotic solvents. All of the polymers had low softing temperatures in the range of 140–260°C, and thermal analyses showed that marked decomposition of the polymers occurred at around 200–300°C, presumably forming quinazolinedione rings by intramolecular deamination. 相似文献
63.
Zhu Chunhong Mochizuki Ayuna Shi Jian Ishimori Minori Koyama Shouhei Ishizawa Hiroaki Yan Jun Morikawa Hideaki 《Cellulose (London, England)》2021,28(12):8139-8152
Cellulose - Some textiles and apparel cannot be laundered, such as astronauts’ clothes on the space station, smart textiles that contain optical fiber electronic devices. Thus, self-cleaning... 相似文献
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65.
Michihiro Ishimori Kenji Tsukigawa Takashige Nakada Teiji Tsuruta 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(2):379-390
The deuterium-decoupled 100 MHz 1H-NMR spectra of 2,3-dideuteromethyloxirane and its polymer prepared with a lattice-disordered zinc dialkoxide were analyzed with consideration of the deuterium isotope effects on proton chemical shifts. The results of 1H- and l3C-NMR studies indicated that the initiator for methyloxirane polymerization catalyzed by the diethylzinc-alcohol system was a lattice-disordered zinc dialkoxide, from the aspect of stereoregularity of the polymers obtained. 相似文献
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67.
Patrick Achenbach Carlos Ayerbe Gayoso Ralph Böhm Olga Borodina Damir Bosnar Vakkas Bozkurt Luka Debenjak Michael O. Distler Anselm Esser Ivica Friščić Yuu Fujii Toshiyuki Gogami Mar Gómez Rodríguez Osamu Hashimoto Satoshi Hirose Hiroki Kanda Masashi Kaneta Eunhee Kim Junichiro Kusaka Amur Margaryan Harald Merkel Ulrich Müller Sho Nagao Satoshi N. Nakamura Josef Pochodzalla Christophe Rappold Joerg Reinhold Takehiko R. Saito Alicia Sanchez Lorente Salvador Sánchez Majos B. Sören Schlimme Matthias Schoth Florian Schulz Concettina Sfienti Simon Širca Liguang Tang Michaela Thiel Kyo Tsukada 《Few-Body Systems》2014,55(8-10):887-892
At the Mainz Microtron MAMI exploratory experiments on the spectroscopy of mesonic weak decays (MWD) of electroproduced Λ-hypernuclei were performed. A unique setup was realized to use the broad momentum-band kaon spectrometer Kaos at zero degree angle with respect to the high-intensity electron beam direction to tag strangeness producing processes. A sample of order 103 MWD from a beryllium target was collected by the coincidence technique with the high-resolution multi-spectrometer facility of the A1 Collaboration. It is conjectured that this sample contains monochromatic two-body decays from stopped hyperfragment decays as well as a wide momentum distribution of quasi-free produced Λ- and Σ-hyperon decays and three-body decays from hyperfragments. Stopped hyperfragments will be identified as monochromatic peaks in the π ? momentum spectrum from which their masses can be extracted with a precision of 50 keV/c 2. 相似文献
68.
The reductive Mg-promoted defluorinative-silylation of 2,2,3,3,3-pentafluoropropiophenone readily produces the α-trifluoromethyl enol silyl ether, which then react with electrophiles to give a variety of 2-substituted-3,3,3-trifluoropropiophenones in excellent yields. The same protocol is applicable for the preparation of enol silyl ether of 3,3,3-trifluoropropiophenone. Fluoride ion catalyzed 1,2-desilylative-defluorination of 2,3,3,3-tetrafluoro-2-trimethylsilyloxypropiophenone provided 3,3,3-trifluoro-1-phenyl-1,2-propanedione in a good yield. 相似文献
69.
Yoshio Imai Motokazu Ishimori 《Journal of polymer science. Part A, Polymer chemistry》1975,13(2):365-371
A novel and successful synthesis of polyimide has been performed by the two-step polymerization of N,N′-bis(phenylsulfonyl)pyromellitimide (BPSP) and bis(4-aminophenyl) ether (ODA). The ring-opening polyaddition reaction proceeded in N-methyl-2-pyrrolidone at room temperature through the formation of the open-chain polyamide, which was subsequently converted by heating to the polyimide along with the elimination of benzenesulfonamide. The polymerization of BPSP with ODA took place fairly rapidly to give the polyamide having inherent viscosity in the range of 0.6–0.8. The polyamide solution was resistant to hydrolysis, but was somewhat susceptible to imidization reaction. The thermal imidization of the open-chain polyamide occurred far more readily than that of the polyamic acid derived from pyromellitic dianhydride and ODA. 相似文献
70.
Stereospecific and Stereoselective Rhodium(I)‐Catalyzed Intramolecular [2+2+2] Cycloaddition of Allene‐Ene‐Ynes: Construction of Bicyclo[4.1.0]heptenes 下载免费PDF全文
Yuu Ohta Dr. Shigeo Yasuda Yuka Yokogawa Kei Kurokawa Prof. Dr. Chisato Mukai 《Angewandte Chemie (International ed. in English)》2015,54(4):1240-1244
Treatment of the allene‐ene‐yne substrates with [{RhCl(CO)2}2] effected the intramolecular [2+2+2]‐type ring‐closing reaction to produce various of tri‐ and tetracyclic derivatives containing a cyclopropane ring. The reaction is highly stereoselective as well as stereospecific with good to excellent yields. 相似文献