Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
Volume 84 , Issue 11
Showing 1-17 articles out of 17 articles from the selected issue
Award Accounts
The Chemical Society of Japan Award for Young Chemists for 2008
  • Shun-ichi Ishiuchi
    2011 Volume 84 Issue 11 Pages 1151-1168
    Published: November 15, 2011
    Released: November 15, 2011
    [Advance publication] Released: October 29, 2011
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    Static structures and dynamics of Ar atom migration in phenol/Ar clusters were investigated by using multiresonance laser spectroscopies which employ more than 3 lasers simultaneously. In the neutral ground state, phenol/Ar (1:1–4) clusters were found to adopt π-bound structure in which all Ar atoms attach to the π-cloud of benzene ring. By considering frequencies of electronic transitions of each cluster, additive rules were found, which suggest that phenol/Ar (1:2–4) clusters adopt (1|1), (3|0), and (3|1) structures, where the notation of (m|n) means that the benzene ring is wedged between m Ar atoms and n Ar atoms. On the other hand, H-bound structure, in which one Ar atom attaches to the end of an OH bond, forms in the cationic ground state generated by laser ionization of the neutral phenol/Ar clusters. According to the principle of vertical ionization, the structures just after the ionization should be π-bound structures, thus this result suggests that one Ar atom migrates from the top of a benzene ring to the end of an OH bond after the ionization. To confirm the existence of such π → H isomerization in cationic state, picosecond time-resolved IR spectroscopy was applied to phenol/Ar (1:2) cluster cation. By measuring the time-resolved IR spectra of OH stretching vibration, the π → H isomerization was successfully observed and found to be an elementary reaction with a time-constant of ≈7 ps. In addition, dynamic peak shift and broadening of the H-bound OH stretching band were observed and interpreted by a simple intramolecular vibrational redistribution (IVR) model.
    Ar atom migration in phenol/Ar cluster cations are observed by time-resolved multiresonance laser spectroscopy. Time-resolved IR spectra of OH stretching vibration clearly show picosecond dynamics of the migration in real time. Fullsize Image
The Chemical Society of Japan Award for Young Chemists for 2009
  • Takashi Uemura
    2011 Volume 84 Issue 11 Pages 1169-1177
    Published: November 15, 2011
    Released: November 15, 2011
    [Advance publication] Released: October 29, 2011
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    In nature, biopolymers are efficiently synthesized by multilevel arrangements of monomers within constrained molecular-level spaces. These biological systems produce regio- and stereoregular polymers with uniform molecular weights, and can also arrange the higher order structures of the resulting polymers. Inspired by the elegant operations of polymerization in biological systems, polymer synthesis in artificial confined geometries is a promising strategy for the control of polymer primary structures and the design of well-defined nanostructures. Recently, we have established a new methodology for controlling polymer synthesis using microporous coordination compounds. In this account, recent progress and future perspectives of polymerizations in these coordination nanospaces are reviewed.
    Polymerizations in channels of porous coordination compounds can allow controls in molecular weight, stereoregularity, reaction position, copolymer sequence, and chain arrangement of resulting polymers. Fullsize Image
BCSJ Award Article
  • Tsukasa Matsuo, Katsunori Suzuki, Tomohide Fukawa, Baolin Li, Mikinao ...
    2011 Volume 84 Issue 11 Pages 1178-1191
    Published: November 15, 2011
    Released: November 15, 2011
    [Advance publication] Released: October 29, 2011
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    A series of octa-R-substituted bromo-s-hydrindacenes, “Rind-Br,” have been synthesized by a sequence of the Lewis acid catalyzed intramolecular Friedel–Crafts reaction, bromination and vice versa. Their structural features and physical properties depend on the eight R-substituents at the four benzylic positions on the s-hydrindacenyl skeleton. The molecular structures of the Rind-Br have been confirmed by X-ray crystallography, indicating the unique structural diversities of the bulky Rind groups.
    A series of bulky “Rind-Br” based on a rigid fused-ring s-hydrindacenyl skeleton have been synthesized by a sequence of the Lewis acid catalyzed intramolecular Friedel–Crafts double cyclization reaction, bromination and vice versa. Fullsize Image
 
  • Shinsaku Fujita
    2011 Volume 84 Issue 11 Pages 1192-1207
    Published: November 15, 2011
    Released: November 15, 2011
    [Advance publication] Released: November 03, 2011
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    Cubane derivatives with chiral and achiral proligands are counted as three-dimensional (3D) structural isomers by the fixed-point matrix method of the unit-subduced-cycle-index (USCI) approach (S. Fujita, “Symmetry and Combinatorial Enumeration in Chemistry,” Springer-Verlag, 1991). The numbers of such 3D structural isomers are itemized with respect to their point-group symmetries, which are subgroups of the point group Oh for a cubane skeleton. For this purpose, the full list of unit subduced cycle indices with chirality fittingness (USCI-CFs) of Oh is constructed in a tabular form. Fixed-point vectors or fixed-point matrices, which are calculated by starting from USCI-CFs, are used to count 3D structural isomers in the form of isomer-counting matrices. A Maple program source for counting cubane derivatives as 3D structural isomers is given as an example of practical calculation.
  • Yasuhiro Yamasaki, Tomohiro Mori
    2011 Volume 84 Issue 11 Pages 1208-1214
    Published: November 15, 2011
    Released: November 15, 2011
    [Advance publication] Released: October 29, 2011
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    In connection with our previous research on μ-oxo-bridged metal phthalocyanine dimers, we have synthesized μ-oxo-bridged subphthalocyanine dimers (μ-oxo subpc dimers) with various peripheral substituents and studied their properties. Compared to the corresponding subpc monomer, the Q-band absorption of subpc dimers broadens, the wavelength undergoes a blue shift by approximately 30–35 nm, and the molar absorptivity is enhanced almost 1.5–2.0 times. Additionally, its solubility in various organic solvents is much improved. We carried out an X-ray crystal structure analysis of [{B(subpc)}2O] and provided a direct observation of its asymmetric structure for the first time.
  • Ken’ichi Aoki, Kunihiro Ichimura
    2011 Volume 84 Issue 11 Pages 1215-1226
    Published: November 15, 2011
    Released: November 15, 2011
    [Advance publication] Released: November 03, 2011
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    An alternate multiaddition (AMA) process consisting of Michael addition and urethane formation is proposed to achieve the quantity synthesis of dendrimers without by-product formation and any weight loss by using commercially available compounds. α-Thioglycerol (TG) was added to pentaerythritol tetraacrylate (PETA) to give the corresponding octaol, but the subsequent reaction with 1,1-bis(acryloyloxymethyl)ethyl isocyanate (BEI) resulted in incomplete urethane formation because of the steric effect of the secondary OH groups. The replacement of BEI with 2-isocyanatoethyl acrylate (AOI) improved the efficiency of the addition of NCO to the secondary OH groups, but an excess amount of AOI was required. Subsequently, we employed the combination of PETA, 2-sulfanylethanol (SE), and BEI. The addition of SE to PETA produced readily the tetraol, which was reacted with BEI to afford dendritic octaacrylate (Ac8b). The repetition of the two addition reactions gave dendritic octaol and hexadecylacrylate (Ac16b), respectively, in large scales. The base-catalyzed Michael addition of 2-naphthalenethiol to acrylate residues of Ac8a and Ac16b gave naphthylthio-terminated dendrimers N8b and N16b, respectively, which were purified by column chromatography. GPC as well as UV-spectroscopic analysis of N8b and N16b revealed that N8b is reasonably monodispersed whereas the purity of N16b is slightly reduced.
  • Bhavesh Bharatiya, Shin-Ichi Yusa, Vinod Aswal, Ludmila Abezgauz, Dgan ...
    2011 Volume 84 Issue 11 Pages 1227-1233
    Published: November 15, 2011
    Released: November 15, 2011
    [Advance publication] Released: October 29, 2011
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    The core–shell–corona forming ABC triblock copolymer poly(styrene-block-2-vinylpyridine-block-ethylene oxide), PS–P2VP–PEO, was synthesized using reversible addition fragmentation chain transfer (RAFT) radical polymerization and characterized by NMR and GPC as PS13–P2VP62–PEO47. The aggregation behavior in aqueous solution as a function of pH and temperature was studied. Turbidity measurements were used to monitor the effects associated with change in pH. The pH-sensitive P2VP block (insoluble above pH >5) and resultant protonation/deprotonation phenomenon plays decisive role in the aggregation. We found that spherical micelles of considerably low aggregation number form at pH <5. SANS and DLS characterization indicate the micelles’ size and spherical shape remained virtually constant in the pH range 1 to 5. The size and shape were further confirmed by cryo-TEM.
  • Kazuyuki Hino, Kiyohiko Nakajima, Miyoko Kawahara, Issui Kiyota, Hiros ...
    2011 Volume 84 Issue 11 Pages 1234-1236
    Published: November 15, 2011
    Released: November 15, 2011
    [Advance publication] Released: October 29, 2011
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    Structures of two polymorphic crystals 1a and 1b of 4′-dimethylamino-3-hydroxyflavone (1) have been determined. Each crystal has intermolecular hydrogen-bonded dimers with the adjacent molecule. The dimeric structure in crystal 1a is nearly planar, whereas that in crystal 1b is slightly bent with respect to the chromane moieties. In both crystals there is a stacking structure of the dimers linked by π–π interactions.
  • Bo-Wei Chen, Chiung-Yao Huang, Zhi-Hong Wen, Jui-Hsin Su, Wei-Hsien Wa ...
    2011 Volume 84 Issue 11 Pages 1237-1242
    Published: November 15, 2011
    Released: November 15, 2011
    [Advance publication] Released: November 03, 2011
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    New eunicellin-based diterpenoids, klysimplexins U–X (14), were isolated from a cultured soft coral Klyxum simplex. Their structures were elucidated by spectroscopic methods, particularly in 1D and 2D NMR experiments. The absolute configuration of 2 was determined by Mosher’s method. Compounds 1 and 2 are the first example of 4-oxygenated eunicellin-type diterpenes isolated from soft corals of this genus.
  • Yong-Mook Hwang, Joji Ohshita, Tomonobu Mizumo, Hiroto Yoshida, Yoshih ...
    2011 Volume 84 Issue 11 Pages 1243-1247
    Published: November 15, 2011
    Released: November 15, 2011
    [Advance publication] Released: November 03, 2011
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    Oligothiophenes end-capped with fused pyridino units were synthesized by means of the Stille coupling and their optical properties were studied. These compounds show absorption maxima and edges at 324–374 nm and 3.10–2.76 eV, respectively, depending on the oligothiophene chain lengths. DFT calculations indicate that both the HOMO and LUMO levels are lowered by the introduction of the pyridino units.
  • Hiroaki Anbou, Rui Umeda, Yutaka Nishiyama
    2011 Volume 84 Issue 11 Pages 1248-1250
    Published: November 15, 2011
    Released: November 15, 2011
    [Advance publication] Released: November 03, 2011
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    For the cesium carbonate-catalyzed α-phenylthiolation of carbonyl compounds with diphenyl disulfide, the yields of the α-phenylthio carbonyl compounds were dramatically improved by the addition of a catalytic amount of diphenyl diselenide.
  • Amirhossein Houshmand, Wan Mohd Ashri Wan Daud, Mohammad Saleh Shafeey ...
    2011 Volume 84 Issue 11 Pages 1251-1260
    Published: November 15, 2011
    Released: November 15, 2011
    [Advance publication] Released: November 09, 2011
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    Tailoring the surface chemistry of adsorbents, especially activated carbons, make them suitable to specific applications. Many times oxidation is the first step and greatly affects the next steps of tailoring. We modified the surface chemistry of a microporous activated carbon (AC) by nitric acid solutions at different conditions of acid concentration, time, and oxidation temperature. The oxidized AC samples were inspected with the aid of physical adsorption–desorption of nitrogen at 77 °C and temperature-programmed desorption (TPD). It was shown that oxidation by nitric acid lowers surface area of the studied AC even at mild severity. Moreover, different instrumental analysis pointed out creation of a considerable amount of oxygen-containing functional groups, especially acidic ones on the surface. Central composite design (CCD) was applied to evaluate the individual and interactive effects of oxidation parameters and to provide a compromise between the amount of oxygen groups and BET surface area as two of studied responses. The significant factors and interactions on each response were recognized by Analysis of Variance (ANOVA). A linear model and a two factor interaction (2FI) model were developed to correlate the oxidation conditions to BET surface area and the amount of oxygen surface groups. In addition, optimized oxidation conditions were established.
  • Balu Krishnakumar, Meenakshisundaram Swaminathan
    2011 Volume 84 Issue 11 Pages 1261-1266
    Published: November 15, 2011
    Released: November 15, 2011
    [Advance publication] Released: November 09, 2011
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    TiO2–SO42−, prepared by sol–gel method has been used for the synthesis of quinoxaline and dipyridophenizine derivatives under microwave irradiation. High-resolution transmission electron microscope (HR-TEM) and atomic force microscope (AFM) images reveal the corrosion of TiO2 particles by sulfuric acid, which causes an increase in the acidity of the catalyst. Sulfate loading by H2SO4 increases catalytic activity of TiO2. This catalyst gives an excellent yield with less reaction time and is an inexpensive, easily recyclable and efficient catalyst for this reaction.
  • Hiroyuki Souma, Ryo Chiba, Shigenobu Hayashi
    2011 Volume 84 Issue 11 Pages 1267-1275
    Published: November 15, 2011
    Released: November 15, 2011
    [Advance publication] Released: October 29, 2011
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    We have modified the surface of TiO2 nanoparticles by propylphosphonic acid (PPA) and decylphosphonic acid (DPA), and have characterized the surface layer of titania (=titanium dioxide) nanoparticles by means of high-resolution solid-state NMR of 31P, 1H, and 13C, X-ray powder diffraction, and themogravimetric analysis. The 31P NMR spectra showed four types of bonding states corresponding to the monodentate and bidentate bonding states. The 1H NMR spectra demonstrated decrease in P–OH groups due to the dehydration condensation reaction. Layered titanium alkylphosphonate was formed by prolonged heating of the mixed solution of the reactants. The layered structure was confirmed by X-ray powder diffraction, and the interlayer distance suggested bilayer arrangement of the n-alkyl chains in the interlayer space. The 31P NMR spectra showed that a tridentate bonding state was formed in the layered structure. The 13C NMR results suggested all-trans conformation of n-alkyl chains, and the methyl group was confined in a small space. The molecular axis of the n-alkyl chains was tilted from the perpendicular of the layer plane. The surface coverage of the organic modifier in the modified TiO2 nanoparticles was estimated from the mass loss of thermogravimetric analysis. The surface coverages are about 50%, except for the samples containing considerable amounts of the layered structure.
  • Jun Ho Shim, Hyun Jung Jung, Youngmi Lee, Chongmok Lee
    2011 Volume 84 Issue 11 Pages 1276-1282
    Published: November 15, 2011
    Released: November 15, 2011
    [Advance publication] Released: November 09, 2011
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    Pd nanoparticles (Pd NPs) on a carbon support (Pd/C) were synthesized in ethylene glycol containing poly(1-vinyl-2-pyrrolidone) (PVP) at various PVP/Pd precursor ratios. The sizes of the Pd NPs were controlled by varying the PVP concentration. Smaller Pd NPs were obtained at higher PVP concentrations. Indeed, the mean sizes of the Pd NPs with PVP/Pd precursor ratios of 0, 40, and 80 (Pd/C-0, -40, and -80) were 2.8 (±1.2), 1.5 (±0.3), and 0.8 (±0.3) nm, respectively, by TEM analysis. The electrocatalytic activities of the Pd/C catalysts toward the oxygen reduction reaction (ORR) were examined in a 0.1 M HClO4 solution using rotating disk electrode voltammetry. The smaller Pd NPs exhibited more efficient ORR properties, such as a more positive ORR onset potential (or half-wave potential, E1/2) and increased number of electrons (n) transferred in the ORR. In particular, the Pd/C-80 catalyst with a lower metal content (7.9 wt % Pd) showed desirable ORR performance in terms of the onset potential, n value, mass activity, and methanol tolerance.
  • Subhash Chandra Laha, Hiroaki Naiki, Kenichi Komura, Yoshihiro Sugi
    2011 Volume 84 Issue 11 Pages 1283-1290
    Published: November 15, 2011
    Released: November 15, 2011
    [Advance publication] Released: November 09, 2011
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    The isopropylation of aromatic hydrocarbons isobutylbenzene (IBB), naphthalene (NP), and biphenyl (BP) was examined over H-mordenite (MOR), H-β (BEA), and H-Y (FAU) zeolites in supercritical carbon dioxide (sc-CO2) medium. MOR was only selective for the formation of the least bulky 4-isobutylcumene (4-IBC) in the isopropylation of IBB. In particular, the catalytic activity and selectivity for 4-IBC were enhanced by the dealumination of MOR; MOR with 110 of SiO2/Al2O3 ratio rendered the highest performance; however, the catalytic activity was decreased by further dealumination. Thermogravimetric analyses confirmed the reduction of coke formation on the catalysts in sc-CO2 medium, preventing the deactivation of MOR. Shape-selective formation of the least bulky isomers, 2,6-diisopropylnaphthalene (2,6-DIPN) and 4,4′-diisopropylbiphenyl (4,4′-DIPB), was also observed in the isopropylation of NP and BP over MOR in sc-CO2. sc-CO2 works as an efficient medium to access and/or replace substrates and their products to/from acidic sites in the MOR channels. In particular, the removal of coke precursors from acidic sites on the zeolite is enhanced by the sc-CO2 medium, resulting in decreased coke formation.
  • Takakazu Yamamoto, Akira Kumagai, Hisashi Kokubo, Yoshiyuki Nakamura
    2011 Volume 84 Issue 11 Pages 1291-1293
    Published: November 15, 2011
    Released: November 15, 2011
    [Advance publication] Released: November 09, 2011
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    π-Conjugated polymers, (Th(R)–CH=CH–Th(R))n (Th(R) = 3-alkylthiophene-2,5-diyl; R = octyl, decyl, and dodecyl), and their dibromo monomers have been prepared. The polymers show a tendency to self-assemble in solutions and in the solid state. X-ray diffraction data suggest that the polymers assume an interdigitation packing in the solid state.
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