Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
Volume 90 , Issue 10
Showing 1-12 articles out of 12 articles from the selected issue
Vol. 90 Commemorative Account: Self-Organization
  • Masaru Mukai, Steven L. Regen
    2017 Volume 90 Issue 10 Pages 1083-1087
    Published: October 15, 2017
    Released: October 15, 2017
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    The lipid raft hypothesis is one of the most significant concepts that has emerged over the past two decades in cell membrane research. In essence, lipid rafts are thought to consist of tightly packed aggregates of cholesterol and sphingolipids that “float in a sea” of fluid phospholipid. Despite its popularity, many basic questions surrounding the lipid raft hypothesis remain to be answered. In particular, their size, their lifetimes and their biological functions have not yet been firmly established. At a more fundamental level, the forces that drive the formation of lipid rafts are not well understood. In this review, recent “nearest-neighbor recognition” (NNR) experiments are discussed that bear on these forces. In particular, these experiments have revealed a major and, heretofore, unrecognized role that polyunsaturated phospholipids are likely to play in the formation of lipid rafts.

    The push and pull forces that we have measured in simple model systems, based on the use of the nearest-neighbor recognition method, leads us to posit that polyunsaturated phospholipids are likely to play a major role in the formation of lipid rafts. Fullsize Image
     
 
  • Mizuki Ozawa, Taro Kimura, Ryo Akiyama, Junpei Miyake, Junji Inukai, K ...
    2017 Volume 90 Issue 10 Pages 1088-1094
    Published: October 15, 2017
    Released: October 15, 2017
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    We report synthesis and properties of a novel series of ammonium-functionalized perfluoroalkylene/aromatic copolymers. In particular, the effect of number and position of ammonium groups on the properties of the copolymer thin membranes was investigated. Fluorenylidene biphenylene groups were used as a scaffold for the ammonium groups. By controlling the chloromethylation reaction conditions, the ammonium groups could be introduced up to 4.0 per fluorenylidene biphenylene unit, resulting in the ion exchange capacity (IEC) of the resulting copolymers ranging from 1.0 to 1.8 meq g−1. The copolymers provided bendable and transparent membranes by solution casting. The membranes exhibited phase-separated morphology based on the hydrophilic/hydrophobic differences in the copolymer components. A copolymer membrane with IEC = 1.0 meq g−1 showed high hydroxide ion conductivity (ca. 70 mS cm−1) at 80 °C in water and good alkaline stability in 1 M KOH aq. over 1000 h at 60 °C. The membrane showed only minor degradation after the long-term alkaline stability test.

  • Tatsuhiko Miyata
    2017 Volume 90 Issue 10 Pages 1095-1104
    Published: October 15, 2017
    Released: October 15, 2017
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    We report the parameter values included in the sigma enlarging bridge (SEB) function for two-component Lennard-Jones fluids within the Ornstein-Zernike (OZ) integral equation framework, which was first proposed in our previous study [T. Miyata, Y. Ebato, J. Molec. Liquids, 217 (2016) 75] to improve the accuracy of the solvation free energy (SFE). In this article, we consider a wide range of thermodynamic states, with varying the solute size and the solute-solvent interaction strength. The SEB parameter was evaluated via the least square fitting of the first rising region of the radial distribution function obtained from OZ theory to that from molecular dynamics simulation. The SEB function was applied to both the hypernetted chain (HNC) and Kovalenko-Hirata (KH) closures. It is found that the SEB parameter increases monotonically with the solute size, whereas it hardly depends on the solute-solvent interaction strength. Also, the performance of bare HNC, bare KH, Percus-Yevick, and Verlet-modified closures are also examined, to report the relationship between the solute volume and the error of the SFE obtained from OZ theory. We found that the SFE errors under both HNC and KH closures are not necessarily proportional to the solute volume.

  • Toyonobu Usuki, Koki Munakata
    2017 Volume 90 Issue 10 Pages 1105-1110
    Published: October 15, 2017
    Released: October 15, 2017
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    The essential oil components linalool, β-ionone, cis- and trans-linalool oxide pyranoid, and trans-linalool oxide furanoid, which are found in the flowers of Osmanthus fragrans var. aurantiacus, were efficiently extracted using a cellulose-dissolving ionic liquid 1-ethyl-3-methylimidazolium methylphosphonate ([C2mim][(MeO)(H)PO2]) as an extraction solvent. Investigation of extraction time revealed that the ionic liquid contributed to the efficient extraction of these essential oils over a shorter extraction time. Scanning electron microscopy (SEM) and fluorescence microscopy observations of the flower petals confirmed the efficiency of the ionic liquid in this extraction process.

BCSJ Award Article
  • Kazuya Arashiba, Aya Eizawa, Hiromasa Tanaka, Kazunari Nakajima, Kazun ...
    2017 Volume 90 Issue 10 Pages 1111-1118
    Published: October 15, 2017
    Released: October 15, 2017
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    We have now found that molybdenum–iodide complexes bearing a PNP-pincer ligand have a higher catalytic activity than the so far reported molybdenum–dinitrogen complexes for ammonia formation from nitrogen gas under ambient reaction conditions, up to 830 equiv being produced based on a dinitrogen-bridged dimolybdenum complex (415 equiv of ammonia based on the molybdenum atom). This remarkable catalytic activity is induced by a novel reaction pathway, where the generation of a dinitrogen-bridged dimolybdenum–iodide complex is a key point to promote direct cleavage of the nitrogen–nitrogen triple bond of the bridging dinitrogen ligand in the Mo–N≡N–Mo core.

    We have now found that molybdenum–iodide complexes bearing a PNP-pincer ligand have a higher catalytic activity than the so far reported molybdenum–dinitrogen complexes for ammonia formation from nitrogen gas under ambient reaction conditions, up to 830 equiv being produced based on a dinitrogen-bridged dimolybdenum complex (415 equiv of ammonia based on the molybdenum atom). Fullsize Image
     
 
  • Maryam Sadat Ghasemzadeh, Batool Akhlaghinia
    2017 Volume 90 Issue 10 Pages 1119-1128
    Published: October 15, 2017
    Released: October 15, 2017
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    In this research 2-aminoethanesulfonic acid immobilized on epichlorohydrin functionalized Fe3O4@WO3 (Fe3O4@WO3-EAE-SO3H) has been introduced as a novel and efficient magnetic nanocatalyst for appropriate and rapid synthesis of 1-substituted-1H-1,2,3,4-tetrazoles. This new nanocatalyst was then characterized using FT-IR, XRD, TEM, EDS, TGA, FE-SEM, CHNS and VSM techniques. The above experimental results allowed determination of the composition of Fe3O4@WO3-EAE-SO3H and clearly revealed that the nanoparticles are spherical in shape with particle size in the range of 7–23 nm and superparamagnetic behavior. Fe3O4@WO3-EAE-SO3H as an excellent replacement for Brønsted acids was shown to be highly efficient in the rapid preparation of 1-substituted-1H-1,2,3,4-tetrazoles through the cyclization reaction of various primary amines, triethyl orthoformate and 1-butyl-3-methylimidazolium azide ([bmim][N3]). Compared with conventional methods, the present protocol has considerable advantages such as short reaction time, mild reaction conditions, easy work-up, pure products with high yields, catalyst recovery using an external magnet and reuse of the catalyst several times without noticeable deterioration in catalytic activity. In addition to the aforementioned favourable properties, the remarkable feature of the present protocol is the use of water as environmentally benign solvent, which eliminates the use of toxic solvent.

Account
  • Yasuhiro Yamada, Takumi Yamada, Yoshihiko Kanemitsu
    2017 Volume 90 Issue 10 Pages 1129-1140
    Published: October 15, 2017
    Released: October 15, 2017
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    Organic-inorganic hybrid lead halide perovskites are currently a most attractive class of materials since they have emerged as a solar cell material that realizes both high efficiency and simple low-cost fabrication. The power conversion efficiencies of perovskite solar cells now exceed 22%, which is comparable to that of commercially available CIGS and CdTe thin film solar cells. The key to further improvement is understanding the physical origin of the high efficiency of the perovskite solar cells, and a tremendous effort to come closer to this target has been made through numerous experiments. In this review article, we discuss the optoelectronic properties of perovskite CH3NH3PbX3 (X = I and Br) solar cell materials. Special attention is given to the free carrier recombination and photon recycling (the re-absorption of photons emitted by radiative recombination of photocarriers) processes in CH3NH3PbX3 single crystals, because a deep understanding of these processes is crucial for improving the solar cell performance. Lead halide perovskites show unique optical properties, e.g., extremely high quantum efficiency of luminescence, small Urbach tail in the absorption spectra, and long lifetime of photocarriers, which all suggest a low density of defects in the crystals. Because of these features, photon recycling efficiently occurs and dominates the optical processes of thick crystals.

    Organic-inorganic hybrid lead halide perovskites show unique optoelectronic properties such as high photoluminescence quantum efficiencies and high solar cell energy conversion efficiencies. In this review article, we discuss the radiative recombination and photon recycling processes of lead halide perovskites for photonic device applications. Fullsize Image
     
 
  • Marziyeh Sadat Masoumpour, Seyed Hosein Mousavipour
    2017 Volume 90 Issue 10 Pages 1141-1151
    Published: October 15, 2017
    Released: October 15, 2017
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    Quasi-classical trajectory calculations at the DFT level and CVT calculations at the CCSD(T) level are performed to study the dynamics of O(3P) + H2S(1A1) reaction on the lowest triplet potential energy surface. In the dynamics part the potential energy surface has been constructed by interpolation technique following the method introduced by Collins and his coworkers. Total and individual classical reactive cross sections are calculated at collision energies from 13.1 to 126.0 kJ mol−1. The rate constants from QCT calculation are compared with those calculated from canonical variational transition state theory at the G3(MP2)B3 and CCSD(T)/Aug-cc-pVTZ levels. The energy partitioning in reactive collisions for the formation of main products (OH + SH and H + HSO) and in non-reactive collisions for the reactants is investigated. At 52.5 kJ mol−1 initial collision energy about 42% and 49% of the total available energy goes into the translational energy and internal motions of H + HSO products, respectively, while for SH + OH products these quantities were found to be about 25% and 40% of the total available energy. The rest of the available energy is allocated in the rotational degrees.

  • Yuanyuan Li, Yuqun Su, Jing Xu, Zhen-liang Xu, Haitao Xu
    2017 Volume 90 Issue 10 Pages 1152-1156
    Published: October 15, 2017
    Released: October 15, 2017
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    In this study, a new Zn coordination polymer (Zn-CP), hereafter, 1Zn, was successfully assembled in a solvothermal system, exhibiting one-dimensional extended chains. 1Zn morphologies were controlled by temperature and surfactants. In addition, the catalytic performance of 1Zn microsized CP was investigated. Knoevenagel condensation after 4 h afforded a conversion of 86%, and a conversion greater than 96% was obtained for 4-chlorobenzaldehyde and 4-bromobenzaldehyde because of their electron-withdrawing ligands. In addition, excellent selectivity was achieved for the degradation (64% conversion) of malachite green in aqueous solution. The microcrystal morphology affected the conversion, and a relative catalytic mechanism was proposed. The developed strategy of shape-controlled assembled CPs will certainly enhance new potential applications of micro-CPs.

  • Masahito Yoshida, Koji Umeda, Takayuki Doi
    2017 Volume 90 Issue 10 Pages 1157-1163
    Published: October 15, 2017
    Released: October 15, 2017
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    A continuous flow synthesis of β-amino acid derivatives has been demonstrated using an asymmetric Mannich reaction. An enolate of tert-butyl acetate was successfully prepared in 10 s at room temperature in a flow reactor, and the desired β-amino acid derivatives were stereoselectively obtained within a short residence time (40 s) in moderate-to-good yields. Sequential N-alkylation of the Mannich product in the flow reactor was also achieved in the presence of DMPU that provided N-alkylated β-amino acid derivatives in good yields.

  • Noboru Kitamura, Yusuke Kuwahara, Yuichi Ueda, Yuki Ito, Shoji Ishizak ...
    2017 Volume 90 Issue 10 Pages 1164-1173
    Published: October 15, 2017
    Released: October 15, 2017
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    The temperature (T) dependences of the emission spectra and lifetimes of octahedral hexanuclear molybdenum(II) ([{Mo6Cl8}Cl6]2− = [1]2−), rhenium(III) ([{Re6S8}Cl6]4− = [2]4−), and tungsten(II) clusters ([{W6Cl8}Cl6]2− = [3]2−) in crystalline or poly(methyl methacrylate) (PMMA) phases were studied. The emission spectrum of the cluster showed a lower-energy shift upon heating from 3 to 70 K, while that shifted gradually to higher-energy above 70 K. The emission spectral shifts of the cluster upon T-elevation accompanied sharp (<50 K) and gradual decreases (>50 K) in the emission lifetime. Such T-dependent emission characteristics, commonly observed for these three cluster complexes, were analyzed by assuming the contribution of the emissions from the excited triplet state spin-sublevels. The large T dependences of the emission lifetimes and spectra of the hexanuclear Mo(II), Re(III), and W(II) clusters can be understood by a single context of the contributions of the emissions from the excited triplet state spin-sublevels.

  • Indra Saptiama, Yusuf Valentino Kaneti, Yumi Suzuki, Yoshitaka Suzuki, ...
    2017 Volume 90 Issue 10 Pages 1174-1179
    Published: October 15, 2017
    Released: October 15, 2017
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    Mesoporous materials with high surface area and pore volume have attracted significant attention as adsorbents as they can provide extensive reaction sites for molybdenum (Mo) adsorption. In this study, we have prepared mesoporous alumina (MA) materials using a soft-templated approach. By changing the applied calcination temperatures, the mesostructural ordering, surface areas, and crystallinity of the MA materials can be varied. Furthermore, the effects of these parameters on their molybdenum (Mo) adsorption properties have been carefully investigated. The findings in this study will provide guidance for designing effective Mo adsorbents using mesoporous materials toward the next 99Mo/99mTc generator preparation.

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