Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
Volume 90 , Issue 9
Showing 1-10 articles out of 10 articles from the selected issue
Vol. 90 Commemorative Account: Self-Organization
  • Makoto Komiyama, Keitaro Yoshimoto, Masahiko Sisido, Katsuhiko Ariga
    2017 Volume 90 Issue 9 Pages 967-1004
    Published: September 15, 2017
    Released: September 15, 2017
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    In this review, we introduce two kinds of bio-related nanoarchitectonics, DNA nanoarchitectonics and cell-macromolecular nanoarchitectonics, both of which are basically controlled by chemical strategies. The former DNA-based approach would represent the precise nature of the nanoarchitectonics based on the strict or “digital” molecular recognition between nucleic bases. This part includes functionalization of single DNAs by chemical means, modification of the main-chain or side-chain bases to achieve stronger DNA binding, DNA aptamers and DNAzymes. It also includes programmable assemblies of DNAs (DNA Origami) and their applications for delivery of drugs to target sites in vivo, sensing in vivo, and selective labeling of biomaterials in cells and in animals. In contrast to the digital molecular recognition between nucleic bases, cell membrane assemblies and their interaction with macromolecules are achieved through rather generic and “analog” interactions such as hydrophobic effects and electrostatic forces. This cell-macromolecular nanoarchitectonics is discussed in the latter part of this review. This part includes bottom-up and top-down approaches for constructing highly organized cell-architectures with macromolecules, for regulating cell adhesion pattern and their functions in two-dimension, for generating three-dimensional cell architectures on micro-patterned surfaces, and for building synthetic/natural macromolecular modified hybrid biointerfaces.

    For building molecular assemblies with cell/tissue engineering techniques and nanotechnology for handling nanomaterials, two kinds of bio-related nanoarchitectonics of different natures are explained. Chemical processes control both precise and fuzzy natures of modification, fabrication, and manipulation of bio-macromolecules, bio-related materials and the cells to construct the architectures that are useful for advanced bio-applications. Fullsize Image
     
Award Account
The Chemical Society of Japan Award for Young Chemists for 2014
  • Tohru Taniguchi
    2017 Volume 90 Issue 9 Pages 1005-1016
    Published: September 15, 2017
    Released: September 15, 2017
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    The configuration and conformation of a molecule affect its bioactivity, reactivity, physical properties, etc., but the analysis of such stereostructures is often difficult and time-consuming. Having envisioned the usefulness of VCD (vibrational circular dichroism) spectroscopy and theoretical VCD/ECD (electronic circular dichroism) calculations in the field of natural product chemistry, the author has applied these techniques to various natural products and other organic molecules. This account describes the author’s studies on molecular structural analysis by means of VCD/ECD theoretical calculations as well as exciton chirality methods. Advantages and limitations of these techniques are also briefly discussed.

    This account describes the author’s studies on structural analysis of various natural products, other organic molecules and macromolecules by means of VCD/ECD theoretical calculations as well as exciton chirality methods. Advantages and limitations of these techniques are also briefly discussed. Fullsize Image
     
 
  • Takashi Hibino, Kazuyo Kobayashi, Peiling Lv, Masahiro Nagao, Shinya T ...
    2017 Volume 90 Issue 9 Pages 1017-1026
    Published: September 15, 2017
    Released: September 15, 2017
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    Cellulosic biomass resources have considerable potential as a renewable energy source that can be used for the cogeneration of electricity and heat. The utilization of these resources generally requires three major systematic processes: gasification, gas processing, and gas utilization. If a power generator could operate using wood resources directly as fuels, then this system could be significantly simplified, thereby reducing initial equipment cost and enhancing application flexibility. An intermediate-temperature fuel cell could possibly realize such an operation; however, the fuel-cell characteristics, especially the catalytic activity of the Pt/C anode, are not sufficient at present. In this study, we attempted to improve the anode activity by alloying Pt with other metals, followed by optimization of the alloy in terms of its atomic ratio and content. The resulting PtFe/C anode yielded higher power densities (37–42 mW cm−2) and energy densities (125–169 Wh kg−1) at 250 °C for fuels composed of cypress, tissue paper, and cotton, compared to those obtained using the Pt/C anode, despite its smaller Pt loading.

  • Shogo Sakai, Mutsumi Yada, Shoko Ito
    2017 Volume 90 Issue 9 Pages 1027-1034
    Published: September 15, 2017
    Released: September 15, 2017
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    The [2+2] photocycloaddition of 2-pyridone and methylacrylate through conical intersections was studied using ab initio molecular orbital (MO) methods. For the cyclic addition of 2-pyridone and methylacrylate, fourteen parallel-type conical intersections were located, which is the same type as that found in ethylene dimers. CiLC (CI/LMO/CASSCF) analysis of the conical intersections indicated that the ratio of regions proceeding toward products and reactants is nearly the same for all parallel-type conical intersections. These intersections are energetically located below the excited state of 2-pyridone and methylacrylate, and the order of the energies of the parallel type conical intersections corresponds to the quantity of products obtained experimentally. The regioselectivity of the photocycloaddition was explained from the conformation of the parallel type conical intersections with polarization.

  • Kazuki Yamamoto, Sayako Koge, Kenji Sasahara, Tomonobu Mizumo, Yoshiro ...
    2017 Volume 90 Issue 9 Pages 1035-1040
    Published: September 15, 2017
    Released: September 15, 2017
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    Bridged polysilsesquioxane membranes containing amine units were prepared from bis[3-(triethoxysilyl)propyl]amine (BTESPA) by a sol-gel process, which consisted of sol formation by hydrolysis/condensation polymerization of BTESPA under neutral conditions and calcination of cast films of the sols on sulfonated polyethersulfone support membrane. A similar treatment of BTESPA, including sol formation under acidic conditions, afforded membrane with ammonium units. Thus-obtained porous BTESPA-based membrane was subjected to reverse osmosis (RO) experiments using 2000 ppm aqueous NaCl solution to examine its water desalination properties. Maximal liquid permeance (1.2 × 10−13 m3/m2·Pa·s) and NaCl rejection (97%) were achieved using the ammonium-containing membrane.

  • Yang Wang, Ryuhei Hosokawa, Takehiko Mori, Tsuyoshi Michinobu
    2017 Volume 90 Issue 9 Pages 1041-1049
    Published: September 15, 2017
    Released: September 15, 2017
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    Fine-tuning of the charge carrier polarity in organic transistors is a fundamental task in order to achieve high-performance organic complementary circuits and related devices. In this article, an efficient methodology for tuning the polarity via rational molecular design is reported. We systematically adjusted the electron affinity of the comonomers in semiconducting copolymers. Thus, three comonomer units, thiophene (T), vinylene (V), and benzothiadiazole (BT), were combined with the benzobisthiadiazole (BBT) unit, leading to three new BBT-based copolymers; i.e., pBBT-T, pBBT-V, and pBBT-BT, respectively. We found that the electron affinity of the comonomer unit decisively affects the absorption spectra, energy levels, thin-film microstructures, and, accordingly, the charge-carrier polarity of the copolymers. pBBT-T with the electron-rich thiophene comonomer showed balanced ambipolar transistor characteristics with the electron/hole mobility ratio (μe/μh) of 2. In contrast, the electron dominant ambipolar characteristics of μe/μh = 14 were achieved by combining BBT with the electron-neutral vinylene group for pBBT-V. Intriguingly, by further strengthening the electron-accepting properties by using the BT unit, unipolar n-type transistors were successfully fabricated based on pBBT-BT. As a result, our findings demonstrated a promising methodology for constructing organic complementary circuits by variation of the electron affinity of the comonomers in BBT-based semiconducting polymers.

  • Yosuke Imanaka, Keita Nakao, Yuri Maeda, Takanori Nishioka
    2017 Volume 90 Issue 9 Pages 1050-1057
    Published: September 15, 2017
    Released: September 15, 2017
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    Sugar-incorporated chelating bis-N-heterocyclic carbene ligand precursors 1,1′-bis(2,3,4,6-tetra-O-acetyl-β-d-glucopyranosyl)-3,3′-ethylene-diimidazolyl ([(bisNHC-C2)H2]2+) and 1,1′-bis(2,3,4,6-tetra-O-acetyl-β-d-glucopyranosyl)-3,3′-propylene-diimidazolyl ([(bisNHC-C3)H2]2+) were synthesized and used to prepare palladium complexes [Pd(bisNHC-C2)Cl2] and [Pd(bisNHC-C3)Cl2], respectively, by direct metallation reaction using dichlorobis(acetonitrile)palladium as a metal source. Catalytic abilities of the complexes for Suzuki-Miyaura coupling in aqueous media were examined and moderate TON (85,000) and TOF (170,000 h−1) were obtained. Because the terminal chloro ligands in the complexes were substituted with solvent molecules or chloride anion and hence 1H NMR spectra of the chloro complexes were complicated, hydrosulfido complexes [Pd(bisNHC-Cn)(SH)2] (n = 2 and 3) were prepared to confirm structures in solution. Dynamic behavior of flapping-wing motion of the bisNHC ligand in [Pd(bisNHC-C3)(SH)2] in solution was evaluated using the signals of the SH protons, which are inequivalent in 1H NMR spectra attributed to the chirality of the glucopyranosyl units.

  • Yu Shu, Jun Maruyama, Satoshi Iwasaki, Cong Li, Yehua Shen, Hiroshi Uy ...
    2017 Volume 90 Issue 9 Pages 1058-1066
    Published: September 15, 2017
    Released: September 15, 2017
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    Hierarchically porous activated carbons (ACs) derived from apricot shell (AS), which is a low-cost and abundant carbon source from a renewable and sustainable biomass waste, were prepared by a green and facile approach via carbonization followed by steam activation and applied to electrodes for symmetric supercapacitors (SCs). The as-obtained AC possessed large surface area and developed porosity with hierarchical pore texture, leading to the specific capacitance of 38.3 F g−1 for an AC//AC symmetrical SC in 20 wt% H2SO4 aqueous electrolyte. Moreover, the assembled AC//AC SC exhibited superior cycling life stability with 99% retention after 6000 cycles at 5 A g−1. These results demonstrate that the present facile, low-cost, and environmentally friendly synthetic strategy for hierarchical ACs from AS can promote the utilization and conversion of AS to high value-added industrial products as well as commercial applications in energy storage devices.

  • Tomoyo Suzuki, Shohei Hemmi, Yuka Kazama, Dai Oyama, Hirotaka Nagao
    2017 Volume 90 Issue 9 Pages 1067-1072
    Published: September 15, 2017
    Released: September 15, 2017
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    A doubly nitrosyl-bridged dinuclear ruthenium complex, {Ru2(µ-NO)2}, bearing tridentate ethylbis(2-pyridylethyl)amine (ebpea) and acetonitrile as supporting and co-existing ligands, respectively, [{Ru(µ-NO)(ebpea)(NCMe)}2]2+ ([1]2+) has been synthesized by a reaction of tris(acetonitrile)ruthenium(II) complex with sodium nitrate in ethanol. The ebpea ligand coordinated with two pyridyl- and one amine-nitrogen atoms in a meridional mode. The dinuclear ruthenium complex containing two nitrosyl ligands bridging between two ruthenium centers as a bending mode, showed two stepwise one-electron oxidation waves at 0.03 and 0.57 V vs. Ag|0.01 M AgNO3 in MeCN and a strong characteristic NO stretching vibrational mode ν(NO) at 1336 cm−1, indicating the electronic structure of the {RuNO}-moieties was an octahedral {RuNO}8-type. The dinuclear ruthenium complex reacted with acid to give mononuclear ruthenium complexes with evolution of dinitrogen oxide.

BCSJ Award Article
  • Takaaki Hiramatsu, Yukihiro Yoshida, Gunzi Saito, Akihiro Otsuka, Hide ...
    2017 Volume 90 Issue 9 Pages 1073-1082
    Published: September 15, 2017
    Released: September 15, 2017
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    Similar to the first quantum spin liquid (QSL) candidate, κ-(ET)2Cu2(CN)3 (1), newly prepared κ-(ET)2Ag2(CN)3 (2) is a dimer Mott insulator with a QSL ground state at ambient pressure and exhibits metallic and superconducting states next to the QSL state under pressure, where ET is bis(ethylenedithio)tetrathiafulvalene. The packing of the ET dimer, which corresponds to a single spin site (S = 1/2), in 2 is similar to that in 1. Salt 2 afforded a two-dimensional equilateral triangular spin lattice having strong geometrical spin frustration (t′/t = 0.967) similar to 1 (t′/t = 1.09), where t and t′ are the interdimer transfer interactions. The geometric relationship between the spin site and the opening in the anion layer in 2 is considerably different from that in 1, resulting in more dispersed packing of ET dimers, narrower bandwidth W, and larger on-site Coulomb repulsion energy U for 2 than 1. As a consequence, 2 has a higher electron correlation U/W, more robust QSL state for wider pressure range and is allocated far away from the itinerant region compared to those of 1. The narrower bandwidth is consistent with a higher superconducting critical temperature for 2 than 1 under pressure.

    Design and preparation of a quantum spin liquid (QSL) candidate having a nearby superconductivity are discussed using structural parameters and band parameters for κ-(ET)2Cu2(CN)3 (1) and κ-(ET)2Ag2(CN)3 (2). Salt 2 has a different key-keyhole relationship from that of 1 resulting in higher Tc of superconductivity and more robust QSL state under pressure than 1. Fullsize Image
     
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