Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
Volume 84 , Issue 12
Showing 1-15 articles out of 15 articles from the selected issue
Award Accounts
The Chemical Society of Japan Award for Creative Work for 2010
  • Zi Liang Wu, Takayuki Kurokawa, Jian Ping Gong
    2011 Volume 84 Issue 12 Pages 1295-1311
    Published: December 15, 2011
    Released: December 15, 2011
    [Advance publication] Released: November 19, 2011
    JOURNALS FREE ACCESS
    The double-network hydrogels (DN gels), developed by our group in 2003, have attracted increasing attention due to their excellent mechanical performance and unique fracture mechanism. The anomalously large fracture energy of DN gels up to 2200 J m−2 originates from the specific combination of two networks with contrasting properties. The first brittle network serves as sacrificial bonds, which breaks into small clusters to efficiently disperse the stress around the crack tip into the surrounding damage zone, while the second ductile polymer chains act as hidden length, which extends extensively to sustain large deformation. The DN gels also exhibit good biocompatibility and low friction resistance. Owing to these superior properties, DN gels possess promising prospective in industrial and medicine fields, especially for load-bearing artificial soft tissues such as artificial cartilage. However, there are several critical problems limiting the practical applications of DN gels, such as how to produce tough artificial tissue with complex shapes or bond a gel to a solid substrate. To address these specific issues, we have developed new systems and techniques based on the DN principle. These achievements, including synthesis of ultrathin DN gels, bonding of one gel to another gel or solid substrate, free-shaping of DN gels, enhancing typical single network gels by creating a DN structure, will be briefly introduced in this account paper. We believe that these new techniques will substantially promote the practical applications of DN hydrogels and extent the DN principle to other systems.
    Novel systems and techniques, including synthesis of ultrathin tough gels, tightly bonding between gel and solid substrate, free-shaping of double-network (DN) gels, enhancing typical single network gel, are developed based on the DN principle and reviewed in this account paper. Fullsize Image
Accounts
  • Yuki Kitazumi, Takashi Kakiuchi
    2011 Volume 84 Issue 12 Pages 1312-1320
    Published: December 15, 2011
    Released: December 15, 2011
    [Advance publication] Released: November 29, 2011
    JOURNALS FREE ACCESS
    On the basis of the dependency of adsorption and partitioning of ionic surfactant on the phase-boundary potential (Δ OWφ ), it is possible to understand in a unified manner various instability phenomena at the liquid|liquid interface in the presence of ionic surfactants, such as spontaneous emulsification, oscillation of Δ OWφ and interfacial tension, and irregularly increased currents on voltammograms of the transfer of surface-active ions across the interface. These instabilities are associated with the electrochemical instability, which defines a thermodynamically unstable condition at the liquid|liquid interface in terms of Δ OWφ and is a fundamental concept to understand the instabilities in the presence of ionic surfactants. The characteristic manifestations of the electrochemical instability, that is, the irregularly increased current on voltammograms in the transfer of surface-active ions, the spontaneous emulsification, and the spontaneous oscillation of Δ OWφ can be designed based on the criterion of the electrochemical instability.
    Instabilities at the liquid|liquid interface, spontaneous emulsification and the oscillation of the phase-boundary potential, can be designed on the basis of the electrochemical instability. Fullsize Image
BCSJ Award Article
  • Hirofumi Nobukuni, Takuya Kamimura, Hidemitsu Uno, Yuichi Shimazaki, Y ...
    2011 Volume 84 Issue 12 Pages 1321-1328
    Published: December 15, 2011
    Released: December 15, 2011
    [Advance publication] Released: November 29, 2011
    JOURNALS FREE ACCESS
    Cyclic nickel and free-base porphyrin dimers (Ni2-CPDPy and H4-CPDPy) include fullerene C70 both in solution and in the crystals. Based on the 13C NMR spectra in solution, the included C70 molecule inside the cavity of Ni2-CPDPy shows both end-on and side-on orientations, whereas the C70 molecule within H4-CPDPy has only a side-on orientation toward the porphyrin rings. X-ray crystallography revealed both “end-on” and “side-on” orientations of C70 in the crystal structure of the inclusion complex of Ni2-CPDPy and C70. This is the first example of an X-ray crystallographic determination for an end-on orientation of C70 cocrystallized with porphyrins. On the other hand, only a side-on orientation of C70 was observed in the crystal structure of the complex of H4-CPDPy and C70. Further, a zigzag array of C70 molecules through van der Waals contacts with each other is formed along the monoclinic b axis in the latter crystal.
    13C NMR and X-ray crystallographic analysis revealed that C70 takes both “end-on” and “side-on” orientations in the cavity of a cyclic nickel porphyrin dimer, whereas C70 adopts only a “side-on” orientation within the corresponding free-base dimer. Fullsize Image
 
  • Hitoshi Matsuki, Masaki Goto, Masataka Kusube, Nobutake Tamai
    2011 Volume 84 Issue 12 Pages 1329-1335
    Published: December 15, 2011
    Released: December 15, 2011
    [Advance publication] Released: November 29, 2011
    JOURNALS RESTRICTED ACCESS
    The packing states in phosphatidylcholine (PC) bilayers under high pressure were studied from fluorescence measurements using a polarity-sensitive probe Prodan. By using the Prodan fluorescence data, three-dimensional image plots, which can visually evaluate the bilayer packing, were constructed for the C16PC bilayer. It turned out from the shape of contours in the image plot constructed by the second-derivative spectra that the Prodan molecules can be distributed into multiple sites in the bilayer and move around the head-group region depending on the phase state. Furthermore, comparing the plot to those for the C17PC and C18PC bilayers, the slight difference in hydrophobicity among the PC molecules produced a marked difference in quantity of the Prodan molecules distributed among the bilayer gel, nonbilayer gel, and liquid crystalline phases of the PC membranes. The present study shows that the imaging using Prodan is useful for the evaluation of lipid bilayer packing.
  • Ryutaro Murata, Tomoaki Yago, Masanobu Wakasa
    2011 Volume 84 Issue 12 Pages 1336-1338
    Published: December 15, 2011
    Released: December 15, 2011
    JOURNALS RESTRICTED ACCESS
    Photocyclization reaction of 1,2-bis(2-methyl-3-benzothienyl)perfluorocyclopentene (BT) in methanol was studied by using nanosecond laser flash photolysis at 296 K. When xanthone was used as a triplet sensitizer, the triplet energy transfer occurred efficiently and the closed-ring product of BT was observed.
  • Masaki Shimizu, Youhei Takeda, Tamejiro Hiyama
    2011 Volume 84 Issue 12 Pages 1339-1341
    Published: December 15, 2011
    Released: December 15, 2011
    [Advance publication] Released: November 29, 2011
    JOURNALS RESTRICTED ACCESS
    We prepared a Pd complex by the oxidative addition of 1,1-dibromo-3,3,3-trifluoro-2-tosyloxypropene to [Pd(PPh3)4]. The atomic distance between Pd and F in the complex was 2.95 Å, which was shorter than the sum of the van der Waals radii, suggesting that Pd–F interaction played an important role in determining the stereochemical outcome of the Pd-catalyzed cross-coupling reaction of the propene.
  • Kiichirou Koyasu, Tomohiro Ohtaki, Fuminori Misaizu
    2011 Volume 84 Issue 12 Pages 1342-1346
    Published: December 15, 2011
    Released: December 15, 2011
    [Advance publication] Released: November 29, 2011
    JOURNALS RESTRICTED ACCESS
    Effective temperature (Teff) dependences of reduced mobilities and collision cross section of small carbon cluster cations, Cn+ (n = 6–25), were investigated by using a drift cell with temperatures of 170–300 K coupled with a reflectron time-of-flight mass spectrometer. We have measured ion mobility within E/N = 16–28 Td, values of which are slightly higher than the general experimental value at low-field conditions. Thus, our conditions should correspond to medium field strength between low- and high-field conditions. Under the present conditions, collision cross section was found to be proportional to Teff−0.1Teff−0.2. The power in the temperature dependence was slightly closer to zero than results obtained previously (A. A. Shvartsburg, G. C. Schatz, M. F. Jarrold, J. Chem. Phys., 1998, 108, 2416). This difference is probably due to E/N, resulting in the difference of relative kinetic energy between Cn+ and buffer gas atoms, in spite of the same Teff region. The result showed that the hard-sphere model is more applicable in the present conditions.
  • Naokazu Yoshikawa, Shinichi Yamabe, Nobuko Kanehisa, Tsuyoshi Inoue, H ...
    2011 Volume 84 Issue 12 Pages 1347-1354
    Published: December 15, 2011
    Released: December 15, 2011
    [Advance publication] Released: December 06, 2011
    JOURNALS RESTRICTED ACCESS
    Emission and electronic properties of eight iridium(III)-centered polypyridine complexes were studied systematically. A crystal structure of [IrBr2(phen)2]PF6 was obtained by X-ray diffraction study, where phen is 1,10-phenanthroline. Those in the triplet states were also determined by DFT calculations to investigate the source of emission spectra. Two triplet structures of [IrX2(bpy)2]+ and [IrX2(phen)2]+ and the transition state of interconversion were obtained with X = Cl and Br. Here, bpy is 2,2′-bipyridine. For the chloro complexes, two triplet species have nonequivalent bpy and phen ligands through pseudo-Jahn–Teller geometric distortion. The dichloro complexes with asymmetric spin density distributions were found to correspond to stronger emission spectra than those for the dibromo compounds. Energies (Eem’s) corresponding to the observed emission wavelengths (λem’s) are in good agreement with the theoretical S0–T1 energy differences (ΔE’s). For [IrBr2(bpy)2]+, Eem = 2.29 eV and ΔE = 2.26 eV. For [IrCl2(bpy)2]+, Eem = 2.29 eV and ΔE = 2.33 eV. For [IrBr2(phen)2]+, Eem = 2.26 eV and ΔE = 2.28 eV. For [IrCl2(phen)2]+, Eem = 2.28 eV and ΔE = 2.34 eV. For all the four complexes, 1A, 1B, 3A, and 3B, DFT calculations indicate Ir–N bond rupture. Tc with a small S0–T1 energy-gap would undergo nonradiative relaxation. Tc indicates a triplet state which is a five-coordinate species with triplet metal-centered character. Coexistence of the triplet state species are discussed in terms of their electronic structures.
  • Shah Raj Ali, Prakash Chandra, Mamta Latwal, Shalabh Kumar Jain, Vipin ...
    2011 Volume 84 Issue 12 Pages 1355-1361
    Published: December 15, 2011
    Released: December 15, 2011
    [Advance publication] Released: December 06, 2011
    JOURNALS RESTRICTED ACCESS
    Cadmium hexacyanidoferrate(III) nanocubes (CdFeNc) have been synthesized and characterized using elemental analysis, thermal analysis, infrared spectroscopy, and X-ray diffraction technique. FE-SEM image showed that nanoparticles have cubic shape with size range 60–90 nm. Electrochemical behavior of CdFeNc has been studied. Electrocatalytic oxidation of morphine was studied using a cadmium hexacyanidoferrate(III) nanocube–carbon nanotube composite modified glassy carbon electrode (CdFeNc–CNT/GCE). The modified electrode reduced the peak potential of morphine by nearly 95 mV. The CdFeNc–CNT/GCE showed a linear response in a concentration range of 500–20 µM. The correlation coefficients (R) for phenolic and t-amine groups of morphine were 0.9925 and 0.9996 respectively while their sensitivity was 3.363 and 4.154 µA µM−1. The CdFeNc–CNT/GCE exhibited a detection limit of 0.21 µM for phenolic and t-amine groups of morphine.
  • Dan-Jing Yang, Shuo Shi, Tian-Ming Yao, Liang-Nian Ji
    2011 Volume 84 Issue 12 Pages 1362-1367
    Published: December 15, 2011
    Released: December 15, 2011
    [Advance publication] Released: November 29, 2011
    JOURNALS RESTRICTED ACCESS
    Mercury, a known neurotoxin, is increasingly believed to be relevant to trigger the pathological positive feedback circle of Alzheimer’s disease (AD). In this study, we originally set out to determine the possible mechanisms for Hg(II)-stimulated fibrillation of R3, which is pivotal to the biochemical properties of full tau protein. In an isothermal titration calorimetry experiment, we demonstrate that R3 shows high affinity to Hg(II), and it yields two types of coordination intermediates in the Hg(II)–R3 binding process. The exceptionally large magnitude of heat release suggests that the most possible coordinating site is the thiol group of cysteine residue (Cys322). By circular dichroism spectrum, we reveal that the coordination of Hg(II) significantly alters the conformation of natively unstructured R3, specifically from random coil to β-turn structure. Furthermore, we find that the tight binding of Hg(II) exerts a pronounced acceleration of the heparin-induced aggregation of R3, giving relatively more R3 filaments, by ThS fluorescence assay and electron microscopy. This investigation could help us to understand the detailed mechanism of misfolding development and self-aggregation of the tau protein from a toxicological perspective of metal ion to AD.
  • Akira Miyazawa, Haruki Shimodaira, Yuji Kawanishi
    2011 Volume 84 Issue 12 Pages 1368-1370
    Published: December 15, 2011
    Released: December 15, 2011
    [Advance publication] Released: December 06, 2011
    JOURNALS RESTRICTED ACCESS
    Upon microwave irradiation, a ring proton at the 4-position and protons at the 2-methyl positions of dimetridazole, 1,2-dimethyl-5-nitroimidazole, and metronidazole, 1-(2-hydroxyethyl)-2-methyl-5-nitroimidazole, were selectively and rapidly exchanged with deuterium at an exchange efficiency in excess of 98 atom % within 30 min.
  • Bo-Wei Chen, Jui-Hsin Su, Chang-Feng Dai, Ping-Jyun Sung, Yang-Chang W ...
    2011 Volume 84 Issue 12 Pages 1371-1373
    Published: December 15, 2011
    Released: December 15, 2011
    [Advance publication] Released: December 06, 2011
    JOURNALS RESTRICTED ACCESS
    Two new hydroxycembranes 1 and 2 and two known epoxycembrane 3 and isocembrol 4 have been isolated from a Formosan soft coral Sinularia facile. The structures of new metabolites were elucidated on the basis of extensive spectroscopic analysis and cytotoxic activity of 14 against the proliferation of a limited panel of cancer cell lines was measured.
  • Koichiro Harada, Hiroshi Yamada, Akihide Takami
    2011 Volume 84 Issue 12 Pages 1374-1382
    Published: December 15, 2011
    Released: December 15, 2011
    [Advance publication] Released: December 06, 2011
    JOURNALS RESTRICTED ACCESS
    Catalytic particulate matter oxidation and its promotion by high oxide ion conductors, Zr–Y–O and Zr–Nd–O, has been studied. Zr-Based oxides show higher particulate matter oxidation activity by O2 compared to a Ce-based conventional catalyst using Pt-loaded oxide coated on a DPF substrate. Isotopic tracer methods involving 18O indicate Zr-based oxides release a large amount of lattice oxygen during carbon oxidation. Also, unique to the Zr-based oxides is an electron and electromotive force generation between carbon-deposited sites and carbon-free sites during carbon oxidation. Zr-Based oxides appear to have the capability to effectively generate oxide ions well suited for carbon oxidation.
  • Masaaki Haneda, Yasuyuki Doi, Masakuni Ozawa
    2011 Volume 84 Issue 12 Pages 1383-1389
    Published: December 15, 2011
    Released: December 15, 2011
    [Advance publication] Released: December 06, 2011
    JOURNALS RESTRICTED ACCESS
    The catalytic performance of Ba–Y2O3 prepared by a coprecipitation method for the direct decomposition of NO was investigated. Although Y2O3 catalyzed NO decomposition, its activity was increased by addition of Ba. The maximum NO decomposition activity was achieved on Ba–Y2O3 with 5 wt % Ba loading. XRD measurements revealed the formation of a solid solution of Ba and Y2O3 as well as BaCO3 small particles, when Ba loading was increased up to 5 wt %. From the comparison between the amount of CO2 desorption measured by temperature-programmed desorption of CO2 (CO2-TPD) and the NO decomposition activity of Ba–Y2O3, highly dispersed Ba species, which is initially present as BaCO3 small particles, on the catalyst surface act as catalytically active sites for NO decomposition. On the basis of in situ observation of surface species formed during NO decomposition by Fourier transform infrared (FT-IR) spectroscopy, we proposed that highly dispersed Ba species plays a role for the formation and adsorption of nitrite (NO2) as reactive species for NO decomposition over Ba–Y2O3 catalyst.
  • Hidetoshi Miyazaki, Yuki Baba, Masaya Inada, Atsushi Nose, Hisao Suzuk ...
    2011 Volume 84 Issue 12 Pages 1390-1392
    Published: December 15, 2011
    Released: December 15, 2011
    [Advance publication] Released: December 06, 2011
    JOURNALS RESTRICTED ACCESS
    Tungsten-based photochromic composite films were fabricated using peroxoisopolytungstic acid aqueous solution and transparent urethane resin. UV–visible irradiation of the resulting composite films showed photochromic properties, indicating broad absorption with peaks at 650 and 900 nm. The coloring time was about 40 min. The colored composite films were transformed to clear film in a dark room in 90 h.
feedback
Top