Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
Volume 77 , Issue 4
Showing 1-30 articles out of 30 articles from the selected issue
Award Accounts
The Chemical Society of Japan Award for Technical Development for 2002
  • Youichi Ohara, Kenkichi Tanaka, Takahiro Hayashi, Haruo Tomita, Shiger ...
    2004 Volume 77 Issue 4 Pages 599-605
    Published: 2004
    Released: April 02, 2004
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    This technology is concerned with a new type of extruded polystyrene foam (XPS), which gives high performance of thermal insulation without containing any fluorocarbons as a blowing agent. Avoiding such typically harmful materials will help solve global environmental problems like ozone layer depletion and global warming. Kaneka Corporation developed this technology for the first time in the world. As a blowing agent of this new XPS in place of fluorocarbons we adopted isobutane, an excellent green gas that helps prevent ozone layer depletion and global warming. However, there is a problem: it is difficult to secure high performance of thermal insulation and flame retardation when isobutane is used. This originates from the fact that isobutane has a higher thermal conductivity than fluorocarbons, and is highly flammable. To overcome the former problem, we found a novel cell structure to secure high performance of thermal insulation, and we developed new technologies to control it. To solve the latter problem, namely securing flame retardation, we clarified the mechanism to suppress combustion of isobutane, and developed a new flame retardation technology by the addition of specific compounds. As a result of a combination of these technologies, we were able to develop and commercialize a new XPS with high performance of thermal insulation. These technologies directly contribute to prevent adverse effects on the global environment such as ozone layer depletion and global warming, by not using fluorocarbons. And, in addition, these technologies indirectly but more greatly contribute to global warming prevention by the reduction in carbon dioxide emissions through a high effect of energy conservation as a thermal insulator. Therefore, the thermal insulator with these technologies is valuable for environmental protection. And as the needs for a material for better energy conservation will increase, the contribution of this technology will expand much more in the future.
  • Jun-ichi Imuta, Akira Todo, Toshiyuki Tsutsui, Toshimi Hachimori, Nori ...
    2004 Volume 77 Issue 4 Pages 607-615
    Published: 2004
    Released: April 02, 2004
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    Advanced supported metallocene catalysts for commercialization were developed in the consequence of improving catalyst performances and accomplishing industrial tasks. The relationship between molecular structures and physical properties of ethylene and α-olefin copolymers produced with metallocene catalysts was also investigated. Metallocene catalyzed ethylene/α-olefin copolymers have excellent physical properties (high strength, high clarity, good heat sealability) owing to a homogeneous molecular structure that had never been achieved by conventional Ziegler–Natta catalysts. We have also succeeded in producing long chain branched ethylene copolymers with narrow molecular weight distributions but excellent melt properties by the use of the catalyst technologies to control of the branches in a polymer chain. Moreover, we have found the first example of metallocene-catalyzed allyl alcohol or allylamine incorporation having only one CH2 chain spacer into the nonpolar polymer backbone, using new metallocene and methylaluminoxane with high activity at high temperature. This is the first example of predominant chain end and/or site-selective introduction of polar groups into the polyolefins.
The Chemical Society of Japan Award for Young Chemists in Technical Development for 2002
  • Yasushi Nakayama, Hideki Bando, Yoshiho Sonobe, Terunori Fujita
    2004 Volume 77 Issue 4 Pages 617-625
    Published: 2004
    Released: April 02, 2004
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    MAO-free new single-site catalyst systems have been developed for olefin polymerization, which are comprised of bis(phenoxy-imine) Ti, Zr, or V complexes (Ti–, Zr–, or V–FI Catalysts) and MgCl2-based compounds. These new catalyst combinations are highly active single-site (Ti–FI Catalysts), exceptionally active (Zr–FI Catalysts), or highly active, thermally robust, single-site (V–FI Catalyst) catalysts for ethylene polymerization. The catalysts can display higher catalytic performance (i.e., catalytic activity, stereoselectivity, thermal stability) than those activated by the well-established MAO activators. In addition, these catalysts are supported, and thus possess a technological advantage vis-à-vis control over polymer morphology, which is essential for commercial application. Therefore, the application of MgCl2-based compounds capable of working both as an activator and a support for non-metallocene complexes provides a conceptually new strategy for the development of high-performance supported single-site catalysts.
Accounts
Analytical and Inorganic
  • Takumi Konno
    2004 Volume 77 Issue 4 Pages 627-649
    Published: 2004
    Released: April 02, 2004
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    The main developments in rational construction of chiral metallo-aggregates based on octahedral metal complexes with 2-aminoethanethiolate (aet) or L-cysteinate (L-cys), as well as their functionality as an S-donating chiral metalloligand, are reviewed in this paper. The reactions of the tris(thiolato)-type fac(S)-[M(aet or L-cys-N,S)3]0 or 3− (M = CoIII, RhIII, IrIII) with transition metal ions gave a variety of S-bridged metallo-aggregates, the structures and chiral properties of which are highly dependent on the nature of the reacting metal ions. The aggregation of the bis(thiolato)-type cis(S)-[Co(aet)2(en)]2+ was also performed through the replacement of a NiII ion in [Ni{Co(aet)2(en)}2]4+ by other transition metal ions. While aggregation of these tris(thiolato)- and bis(thiolato)-types of octahedral units commonly produced discrete S-bridged polynuclear structures, one-dimensional and two-dimensional extended polymeric structures, besides a discrete trinuclear structure, were constructed by the reactions of the mono(thiolato)-type [Co(aet or L-cys-N,S)(en)2]2+ or + with silver(I) ion, because of the adoption of μ3-thiolato bridging mode and/or the coordination ability of the free carboxylate group.
Headline Articles
Theoretical and Physical
  • Jun-ichi Aihara
    2004 Volume 77 Issue 4 Pages 651-659
    Published: 2004
    Released: April 02, 2004
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    Molecular dianions/dications of many polycyclic aromatic hydrocarbons (PAHs) have long been regarded as antiaromatics because of their global paratropic π-electron current. However, many of them are supposed to be aromatic due to their positive topological resonance energies (TREs). In order to reconcile such energetic and magnetic criteria of aromaticity, we derived a new TRE-like energetic quantity from the magnetic response of the π-system and called it a magnetic resonance energy (MRE). MRE was found to be highly correlative with TRE for a variety of PAHs and their molecular dianions/dications. We can now discuss energetic and magnetic criteria of aromaticity unambiguously on this theoretical basis. Many PAH dianions/dications indeed turned out to be aromatic with positive MREs even if they exhibit paratropic currents along the periphery of the π-system.
Articles
Theoretical and Physical
  • Anupam Singh, Ajay Kumar Singh, Nand Kumar Mehrotra
    2004 Volume 77 Issue 4 Pages 661-665
    Published: 2004
    Released: April 02, 2004
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    The present communication reports on the experimental values of the mutual viscosity (η12) and NMR spin-lattice time (T1) of o-nitrobenzoic acid, m-nitrobenzoic acid, p-nitrobenzoic acid, o-hydroxybenzoic acid, m-hydroxybenzoic acid, p-hydroxybenzoic acid, and m-chlorobenzoic acid. The small difference between the values of η12 and η1 suggests that the basic model of the dielectric relaxation process does not suffer any major changes even when η12 is used instead of η1. The experimental values of the NMR spin-lattice relaxation time (T1) have been correlated with the calculated values of T1 obtained using various equations of the dielectric relaxation time (τ). It has been concluded that the equations of Writz and Murty are better representations of the dielectric relaxation phenomenon.
  • Kei Sato, Björn Klotz, Shiro Hatakeyama, Takashi Imamura, Yuuki W ...
    2004 Volume 77 Issue 4 Pages 667-671
    Published: 2004
    Released: April 02, 2004
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    Aerosol formation in toluene–NOx–air–photoirradiation systems was examined in a 6-m3 photochemical reaction chamber. The initial toluene concentration was varied between 2 and 16 ppmv, whereas the initial NOx concentration was kept constant. The aerosol mass concentrations were plotted as a function of the concentration of toluene reacted. The aerosol profiles showed a curved feature at low toluene consumptions, and merged into a single line at longer reaction times. The observed characteristics were explained by assuming condensable products were formed through reactions of ozone with primary toluene photo-oxidation products.
  • Yoshihiko Komori, Shigenobu Hayashi
    2004 Volume 77 Issue 4 Pages 673-679
    Published: 2004
    Released: April 02, 2004
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    The dynamics of deuterated p-nitroaniline (pNA-d) molecules in zeolite ZSM-5 including Na+ (NaZSM-5) were investigated by means of 2H and 13C solid-state NMR to clarify the effects of Na+ and hydrated Na+. The adsorbed amount of pNA-d was four molecules per unit cell of NaZSM-5. 2H NMR spectra of a dehydrated sample indicated that the motion of pNA-d in the micropore is a 180°flip-flop around the C2 axis of the molecule. Another species with a faster flip-flop motion was distinguishable and assigned to pNA-d on the outer surface. When the sample adsorbed water molecules, 2H spectra showed that the flip-flop motion of pNA-d was largely suppressed in the micropore and that pNA-d on the outer surface underwent an isotropic motion. These results indicated that the dynamics of pNA-d in NaZSM-5 depended on the interactions with Na+ and hydrated Na+ as well as on the location.
  • Usama Mohamed Rabie, Hasan Mahmoud Ali Salman, Moustafa Hassan Mohamed ...
    2004 Volume 77 Issue 4 Pages 681-686
    Published: 2004
    Released: April 02, 2004
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    Charge-transfer complexes of 1,2,4-triazole (1T), 3-amino-1,2,4-triazole (2T), 4-amino-4H-1,2,4-triazole (3T), and guanazole (3,5-diamino-1,2,4-triazole) (4T) with iodine as a typical σ-type acceptor and with typical π-type acceptors (tetracyanoethene (TCNE) and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ)) have been synthesized and characterized. The spectral characteristics and thermodynamic properties of such CT complexes were investigated. The system triazoles/iodine is characterized by the formation of triiodide ions (I3), which is proposed to occur via the initial formation of outer-sphere charge-transfer complexes. The systems (1T–4T)/TCNE and (1T–4T)/DDQ produced the corresponding anion radicals, TCNE•− and DDQ•−, respectively. The time dependency of the spectral bands due to the 4T/TCNE system is discussed in terms of the scope of transformation from outer-sphere CT complexes to inner-sphere ones. Meanwhile, for the system 4T/DDQ the time dependency is accounted for by the stepwise reduction of DDQ to its anion radicals, and then to the corresponding hydroquinone (2,3-dichloro-5,6-dicyanohydroquinone), DDQH2. However, because the resulting in situ (DDQH2) was an unconventional new acceptor, it formed a CT complex with the donor (4T). The results show that the formed complexes are strong kinds of n–σ and n–π types in a 1:2 and 1:1 stoichiometry for the complexes of triazoles donors with iodine and DDQ, respectively.
  • Hirotoshi Mori, Eisaku Miyoshi
    2004 Volume 77 Issue 4 Pages 687-690
    Published: 2004
    Released: April 02, 2004
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    The topologies of hydrogen-bond potential energy surfaces of one-dimensional assembled 2,2′-biimidazole (H2bim) and its deprotonated Ni complex ([NiII(Hbim)2]) were investigated by density functional theory calculations at the B3LYP/CEP-31G(d,p) level. It was revealed that the formation of coordination bonds between Hbim and Ni makes the N–H···N hydrogen bond between Hbim units linear and strong.
  • Yasuharu Nagai, Nobuyuki Matubayasi, Masaru Nakahara
    2004 Volume 77 Issue 4 Pages 691-697
    Published: 2004
    Released: April 02, 2004
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    Hot water in its undissociated form has been kinetically proven to induce a chemical reaction that does not undergo under ambient conditions in the absence of a strong acid. The water-induced and acid-catalyzed rate constants were separately determined for the dehydration of 1,4-butanediol by varying the oxonium ion (H+) concentration. It was found on the kinetic level over a wide range of temperature from moderate to supercritical that the undissociated form of water promotes the reaction at an effective acid concentration of 10−4–10−6 M. A strong density dependence of the reaction rate constant was further observed under supercritical condition, and is related to the anomalous temperature dependence of the rate constant near the critical point.
Analytical and Inorganic
  • Akira Hanaki, Toshihiko Ozawa, Yasuhiro Funahashi, Akira Odani
    2004 Volume 77 Issue 4 Pages 699-707
    Published: 2004
    Released: April 02, 2004
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    The kinetic stability of a chelate-ring unit in Cu(H−1GlyGly), Cu(H−1β-AlaGly), and Cu(EDMA) complexes has been inspected by stopped-flow spectroscopy. Those three Cu(II) complexes reacted with cysteine (CysH) or penicillamine (PesH) to form primarily ternary complexes, formulated as Cu(H−1L)(Rs); L = GlyGly and β-AlaGly, and Cu(EDMA)(Rs); where Rs represents the aminothiolates. The chelate-ring units composed of [N-(Gly)]-, [N-(β-Ala)]-, and [N-(2-aminoethyl)]-moieties in Cu(H−1GlyGly), Cu(H−1β-AlaGly), and Cu(EDMA) were conserved, respectively, in the corresponding ternary complexes. The rate of the ternary complex formation was very rapid, so much so that the rate constants, k1+, could not be determined by the conventional stopped-flow techniques. The ternary complexes upon forming reacted with the RsH to produce the binary Cu(Rs)2 species. Thus, the observables were limited to the rate constants, k2+, for the transformation from Cu(H−1L)(Rs) to Cu(Rs)2. The kinetic stabilities of those chelate-ring units were compared based on the rate constant, k2+, and equilibrium constant, K2. The stability was arranged as follows: [N-(Gly)]- > [N-(2-aminoethyl)]- > [N-(β-Ala)]-unit. Though Cu(EDMA) was kinetically stable, the Cu(II) in Cu(EDMA)(Rs) was rapidly delivered by a nucleophilic attack of RsH to form Cu(Rs)2. On the contrary, Cu(H−1GlyGly) was kinetically less stable than Cu(EDMA), but delivery of the Cu(II) from Cu(H−1L)(Rs), by the proton-assisted mechanism, was comparatively slow.
  • Pratap Kumar Saha, Surajit Banerjee, Sandip Saha, Alok Kumar Mukherjee ...
    2004 Volume 77 Issue 4 Pages 709-714
    Published: 2004
    Released: April 02, 2004
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    A new zeolite-immobilized copper(II) complex catalyst has been prepared by entrapping [CuL] [LH2 = N,N′-(1,1-dimethylethylene)bis(salicylaldiimine)] on NaY zeolite matrix. The reaction of Cu–NaY and molten LH2 affords a green mass of crude catalyst that upon a treatment with CH3CN gives a gray-colored hybrid catalyst (CuL–NaY). The prepared catalyst has been characterized by IR and UV–vis spectroscopic and EPR spectrometric measurements, TG–DTA analysis, powder X-ray diffraction, and surface-area measurements. To ascertain the structure of the immobilized complex, a single-crystal X-ray diffraction analysis of [CuL] was performed. Spectroscopic measurements showed that the green crude of CuL–NaY contains a penta- or hexa-coordinated copper(II) moiety, while the CuL–NaY catalyst contains a distorted square-planar [CuL] complex moiety. A remarkable catalytic activity of the prepared hybrid catalyst has been observed in oxidation reactions of 1-naphthol and norbornene.
  • Junichi Nishijo, Akira Miyazaki, Toshiaki Enoki
    2004 Volume 77 Issue 4 Pages 715-727
    Published: 2004
    Released: April 02, 2004
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    A new series of molecule-based magnets, including crown thioether (9S3 = 1,4,7-trithiacyclononane) complexes of transition metals (Ni, Co, Cu), are presented. TCNQ salts [M(9S3)2](TCNQ)2 (M = Ni, Co) are one-dimensional (1D), antiferromagnetic (AF) complexes with an intra-chain interaction J = −3.9 K and −1.3 K for M = Ni and Co, respectively, despite its long intermolecular distance, for which the large spin density on the sulfur atom in the magnetic [M(9S3)2]2+ cation is responsible. The mixed valence salt [M(9S3)2](TCNQ)3 (M = Ni, Co) is a paramagnetic semiconductor. 1D AF magnet [Cu(9S3)Br2] does not undergo any magnetic transition because of the weak inter-chain interaction. Substituting a very small amount (∼5%) of Cu with Ni causes a structural change. The change decreases the distances of inter-chain S–S contacts, resulting in the generation of an AF transition at TN = 4.5 K. [M(9S3)2][Ni(bdt)2]2 (M = Ni, Co; bdt = 1,2-benzenedithiolato) are weak-ferromagnets with TN = 6.2 K and 2.6 K for M = Ni and Co, respectively. In the crystals, [M(9S3)2]2+–[Ni(bdt)2] alternate chains and [Ni(bdt)2] uniform chains coexist. The appearance of weak-ferromagnetism is associated with a competition between two kinds of inter-chain AF interactions between [M(9S3)2]2+–[Ni(bdt)2] alternate chains, where the stronger one is an indirect inter-chain interaction through [Ni(bdt)2] uniform chains, while the weaker is a direct inter-chain interaction.
  • Yoshinori Takano, Lallan P. Gupta, Hodaka Kawahata, Katsumi Marumo, Yo ...
    2004 Volume 77 Issue 4 Pages 729-732
    Published: 2004
    Released: April 02, 2004
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    Core samples of sediments at depths of 0–300 cm at Rikubetsu, Hokkaido, Japan were analyzed for hexosamine (HA) of glucosamine (Gluam) and galactosamine (Galam). The Gluam and Galam contents were highest at the surface, and drastically decreased with increasing depth: the Gluam and Galam contents were 7.98 and 3.19 μmol/g at a depth of 0–5 cm, respectively. Highly positive correlations for Gluam and Galam versus the microbial cell density, total organic carbon, and total hydrolyzed amino acids were observed. The present results suggest that an exponential degradation for amino compounds on the early stage of diagenesis had occurred, and then the amino compounds decreased asymptotically with time. The degradation rate of amino sugars was slower than that of amino acids in the terrestrial diagenetic pathway. The present study shows the vertical distribution of amino sugars with the trends of other biochemical indicators.
  • Kazuhide Ikeda, Kanako Matsufuji, Masaaki Ohba, Masahito Kodera, Hisas ...
    2004 Volume 77 Issue 4 Pages 733-739
    Published: 2004
    Released: April 02, 2004
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    A tetranucleating macrocyclic ligand with four endogenous phenolic groups is obtained by the condensation of 3-aminomethyl-5-methylsalicylaldehyde in the presence of metal ion as two tetranuclear NiII complexes, [Ni4(L)(OH)(H2O)4](ClO4)3 (1) and [Ni4(L)(O)(dmf)4](ClO4)2 (2), and a dinuclear MnIII complex, [Mn2(H2L)(OH)(AcO)2(H2O)]Br (3). X-ray crystallographic studies for [Ni4(L)(OH)(H2O)8](ClO4)3·7H2O (1′) indicate that the macrocyclic ligand accommodates four NiII ions, producing a square Ni4 core with μ4-hydroxo group at the center of the core. Water molecules occupy the axial sites of each Ni affording a nearly octahedral geometry about the metal. Complex 2 has a similar tetranuclear Ni4-core possessing a μ4-oxo group at the center of the core. In complex 3, the di-protonated ligand (H2L)2− accommodates two MnIII ions, affording a (μ-hydroxo)(μ-acetato)dimanganese(III) core. Magnetic studies for 1 and 2 indicate a ferromagnetic interaction between the adjacent NiII centers and an antiferromagnetic interaction between the diagonal NiII centers. Complex 3 shows a weak antiferromagnetic interaction between the two MnIII ions.
  • Tohru Wada, Tetsuaki Fujihara, Mizuno Tomori, Dai Ooyama, Koji Tanaka
    2004 Volume 77 Issue 4 Pages 741-749
    Published: 2004
    Released: April 02, 2004
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    Monocarbonylruthenium complexes with a semiquinone ligand, ([Ru(CO)(sq)(L)]n+ (sq = 3,5-di-tert-butyl-1,2-benzosemiquinone, n = 1 or 0, L = 2,2′:6′,2″-terpyridine ([1]+), 2,6-bis(N,N-dimethylaminomethyl)pyridine ([2]+), 2,6-di-2′-pyridylphenyl ([3]0), or 2-(2,2′-bipyridin-6-yl)phenolato ([4]0)), and dicarbonylruthenium complexes with two semiquinone ligands, [Ru(CO2)2(sq)2] ([5]0) and [Ru(CO)2(phsq)2] (phsq = 9,10-phenanthrasemiquinone, [6]0), were synthesized and the structures of [1]+ and [6] were determined by X-ray crystal analysis. Monocarbonyl Ru(II)–dioxolene complexes displayed the ligand localized catecholato/semiquinone and semiquinone/quinone redox couples, and two sets of those redox couples were observed in the dicarbonyl Ru(II)–bis(dioxolene) complexes. Spectroelectrochemical study revealed that the Ru(II)–catecholato and Ru(II)–semiquinone complexes were stable in solutions, while the Ru(II)–quinone complexes underwent fragmentation in solutions. One-electron reduction of the monocarbonyl Ru(II)–semiquinone complexes caused a red shift of the ν(CO) bands in a range of 41 to 56 cm−1, which was substantially larger than those of carbonyl Ru(II)–polypyridyl complexes. Two ν(CO) bands of dicarbonyl Ru(II)–bis(semiquinone) complexes also shifted to lower wavelength in a range of 53 to 99 cm−1 upon two electron reduction of the complexes. The unusually large red shift of ν(CO) bands upon reduction of carbonyl Ru(II)–dioxolene complexes compared with those of Ru(II)–polypyridyl complex is ascribed to a strong electronic interaction between carbonyl and dioxolene ligands.
  • Eun Jeong Nam, Jun Ho Kim, Bong-Ok Kim, Sung Min Kim, No Gill Park, Yo ...
    2004 Volume 77 Issue 4 Pages 751-755
    Published: 2004
    Released: April 02, 2004
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    Tris(1-phenyl-κC1-pyrazolato-κN2)iridium (Ir(ppz)3) was prepared and its luminescence properties were investigated for the application to organic light-emitting devices (OLEDs). The photoluminescence (PL) spectra of Ir(ppz)3 in dichloromethane showed a peak at 437 nm at room temperature. The luminescent lifetime of an Ir(ppz)3 film doped in CBP was found to be 218 ns, which indicated that its emission is phosphorescent. OLEDs were fabricated with doped films of Ir(ppz)3 in several hosts, and the electroluminescence (EL) peak was observed at 450 nm. The luminance of OLEDs was pure blue, with the CIE coordinates of x = 0.158, y = 0.139 at 100 cd/m2, but luminous efficiencies were low since the LUMO of Ir(ppz)3 is higher than those of the hosts used.
  • Tetsushi Yamamoto, Hengbo Yin, Yuji Wada, Takayuki Kitamura, Takao Sak ...
    2004 Volume 77 Issue 4 Pages 757-761
    Published: 2004
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    The morphologies of Ag particles can be controlled between distorted sphere and prism by employing microwave-promoted reductions of highly concentrated 0.1 M silver nitrate in aqueous solutions. We can selectively synthesize either sphere-Ag or prism-Ag particles by changing only an additive, i.e., either trisodium citrate/formaldehyde or poly(N-vinyl-2-pyrrolidone) (PVP). The particle sizes and size distributions of sphere-Ag particles are strongly dependent on the concentration of trisodium citrate.
  • Takashiro Akitsu, Yasuaki Einaga
    2004 Volume 77 Issue 4 Pages 763-764
    Published: 2004
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    The thermal and photo-responsibility of the axial semi-coordination Cu–O bonds in [Cu(en)2](ClO4)2 (1) (en = ethylenediamine) have been investigated. We discovered a new photoresponsive behavior that was attributed to photo-induced ClO4 cleavage accompanied by compression of the Cu–O bonds using the structural degree of freedom of the semi-coordination bonds.
Organic and Biological
  • Lopamudra Homchaudhuri, Rajaram Swaminathan
    2004 Volume 77 Issue 4 Pages 765-769
    Published: 2004
    Released: April 02, 2004
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    There is a need for an intrinsic spectral probe to monitor key events like protein unfolding and aggregation in a rapid and unambiguous manner. Protein aggregation is an important issue, but ironically there is a dearth of simple techniques to directly detect the presence of aggregates in solution. We report here the hitherto undiscovered electronic absorption around 300–350 nm in aqueous solutions (pH 7) of human serum albumin (HA), calf thymus histone, and poly-L-lysine. The above spectra were significantly absent in controls like subtilisin carlsberg, mutant barstar, and lysozyme. The possibilities that Rayleigh scattering or impurities could account for the above spectra were checked and ruled out. Based on the analysis of available three-dimensional structures from PDB and our earlier work on the lysine amino acid, an intramolecular interaction between lysine side chains in close spatial proximity was deduced to be the origin for the above spectra. The utility of Lys–Lys interaction in detecting protein unfolding and aggregation in a lysine-rich protein like calf thymus histone using near-ultraviolet absorption is demonstrated.
  • Noriaki Yamauchi, Hideyoshi Ueoka, Norisuke Kamada, Tatsushi Murae
    2004 Volume 77 Issue 4 Pages 771-778
    Published: 2004
    Released: April 02, 2004
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    We investigated the biosynthesis of the unique structure of calditol, a part of the characteristic lipid molecules in the major part of thermophilic archaea, Sulfolobus sp. Deuterium-labeling experiments with deuterated glucose substrates, were carried out. The results clarified that calditol was biosynthesized from glucose with C–C bond formation between C-1 and C-5, and no loss of deuterium at C-6 of glucose was observed. Two reaction mechanisms were possible when these experimental findings, and conventional reports were considered. Among these, the course that assumes C-4 oxidation as the starting point would be preferable from the resemblance to myo-inositol biosynthesis. Furthermore, the high deuterium incorporation at C-1 of calditol from C-1 of glucose suggests that activation, such as oxidation at C-1, is not involved in the ether C–O bonding.
  • Yoshinori Takano, Taiki Tsuboi, Takeo Kaneko, Kensei Kobayashi, Katsum ...
    2004 Volume 77 Issue 4 Pages 779-783
    Published: 2004
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    High-molecular-weight organic matter synthesized from mixtures of carbon monoxide, ammonia, and water gases similar to those found in the interstellar medium were irradiated with a 3 MeV proton beam and analyzed by Curie-point pyrolysis with detection by a gas chromatograph and a mass spectrometer (Pyr–GC–MS). A wide variety of organic compounds, not only a number of amide compounds, but also heterocyclic and polycyclic aromatic hydrocarbons (PAHs), were detected among the products of the pyrolysis. Detection of biologically interesting compounds, such as glycolamide (HOCH2CONH2), is also cosmochemically interesting. The present data show that primary and primitive organic matter serving as “precursors” to bioorganic compounds, such as amino acids, nucleic acid bases, and sugar, might have been formed in a gaseous mixture of similar composition to that of the interstellar dust environment. Consequently, the matrix of extraterrestrial organic compounds delivered by comets and meteorites may have played an important role in the early stages of chemical evolution on the primitive Earth.
  • Shunsuke Chiba, Mitsuru Kitamura, Osamu Saku, Koichi Narasaka
    2004 Volume 77 Issue 4 Pages 785-796
    Published: 2004
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    Various 1-azaazulenes are synthesized from cycloheptatrienylmethyl ketone O-pentafluorobenzoyloximes by treatment with a catalytic amount of Pd(dba)2t-Bu3P (dba = dibenzylideneacetone) and triethylamine in the presence of MS 4A via alkylideneaminopalladium(II) intermediates generated by oxidative addition of the oximes to a Pd(0) complex.
  • Shin-ichi Sasaki, Hitoshi Tamiaki
    2004 Volume 77 Issue 4 Pages 797-800
    Published: 2004
    Released: April 02, 2004
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    31-Epimerically pure C8-formyl analogues Zn–3R/S of zinc methyl bacteriopheophorbide-f (Zn–MBPhe-f) were synthesized. Their spectroscopic and self-aggregation properties were compared to those of Zn–MBPhe-f possessing the C7-formyl group (Zn–2R/S) as a model compound of bacteriochlorophyll-f. Movement of a formyl group from the 7- to 8-position as in Zn–2 → Zn–3 caused large spectral changes in both monomeric and oligomeric forms. Monomeric Zn–3R/S in THF showed a more red-shifted Qy peak (650 nm) than Zn–2R/S (628 nm), but both afforded the same Soret maximum at 448 nm. Self-aggregates of Zn–3R/S in 6% (v/v) THF–H2O gave a more red-shifted Qy peak accompanied by a large diastereomeric control in the oligomeric Qy peaks.
  • Toshiaki Suzuki, Yuji Kaneko, Masashi Ikegami, Tatsuo Arai
    2004 Volume 77 Issue 4 Pages 801-806
    Published: 2004
    Released: April 02, 2004
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    The hydrogen abstraction reaction and rearrangement reaction of aroylmethyl radicals were studied by product analyses and transient absorption spectroscopies. The α-bromoacetylarenes examined in this study gave aroylmethyl radicals by C–Br bond cleavage upon photoirradiation. According to the results of the product analysis, the rearrangement reaction takes place in the aroylmethyl radicals produced on irradiation of 1-bromoacetylnaphthalene (1-BAN) and 9-bromoacetylanthracene (9-BAA). The rate constants of the rearrangement reaction resulting in an arylmethyl radical and the hydrogen abstraction reaction resulting in an acetylarene for aroylmethyl radicals were estimated based on the results of laser flash photolysis and product analysis.
Applied and Materials
  • Supitcha Thongchant, Shinya Katagiri, Yasuchika Hasegawa, Yuji Wada, S ...
    2004 Volume 77 Issue 4 Pages 807-812
    Published: 2004
    Released: April 02, 2004
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    The cation-exchange of zeolite X with divalent europium has been achieved using a methanol solution containing Eu(II) prepared by photochemical reduction of Eu(III). Emission spectra have confirmed that the valence of europium ion in the ion-exchanged zeolite X was divalent. A blue shift of emission spectra was observed after exposing Eu(II)X to air at room temperature. TEM have revealed the formation of EuO nanocrystals with average size of 4.2 nm on the outer surface of Eu(II)X. EuO nanocrystals show ferromagnetism accompanied by photo-response magnetism under UV irradiation.
  • Masaaki Kubota, Akinobu Shiga, Hideyuki Higashimura, Kiyoshi Fujisawa, ...
    2004 Volume 77 Issue 4 Pages 813-818
    Published: 2004
    Released: April 02, 2004
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    Ab initio calculation on the reaction mechanism of “radical-controlled” oxidative polymerization (RCOP) of phenol catalyzed by μ-η22-peroxo dicopper(II) complex (1) was performed. The key step is the reaction of 1 with phenol, for which two reaction routes have been postulated. One is through phenoxo copper(II) intermediate (route X), and the other is via the abstraction of hydrogen atoms from phenol (route Y). All structures of the possible intermediates in both routes were optimized, and the energy profiles of these routes were compared with each other. For the reaction of 1 with phenol, route X would be favored more than route Y based on the present calculation results and previous experimental data. In comparison, the reaction of 1 with 2,4-di-t-butylphenol, which has a bulky substituent at the o-position, was evaluated in a similar manner. Route X may also be possible in this reaction.
  • Hiroto Kudo, Kouji Mitani, Tadatomi Nishikubo, Masaya Mitsuishi, Tokuj ...
    2004 Volume 77 Issue 4 Pages 819-826
    Published: 2004
    Released: April 02, 2004
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    The syntheses and photoinduced deprotection reactions of calix[4]resorcinarene derivatives with pendant t-butyl ester moieties were examined. Calix[4]resorcinarenes, 1a1h, were prepared by the condensation reaction of resorcinol with certain aldehydes in the presence of hydrochloric acid as a catalyst in ethanol at 80 °C for 30 min in good yields. The substitution reaction of 1a1h with t-butyl bromoacetate using cesium carbonate as a base and tetrabutylammmonium bromide (TBAB) as a phase transfer catalyst was performed to afford the corresponding calix[4]resorcinarene derivatives, 2a2h with pendant t-butyl ester groups. It was found that 2a, 2e, 2f, 2g, and 2h had film forming properties. The photo-induced deprotection reaction of calixarene derivatives 2a, 2e, 2f, 2g, and 2h was examined in the presence of bis-[4-(diphenylsulfonio)phenyl] sulfide (DPSP) as a photoacid generator in the film state upon UV irradiation for 5 min followed by heating at 170 °C. It was found that the deprotection reaction of the t-butyl ester groups of 2a, 2e, 2f, 2g, and 2h proceeded smoothly to produce the corresponding calixarene derivatives, 3a, 3e, 3f, 3g, and 3h with carboxylic acid groups, quantitatively.
  • Kensuke Naka, Dong-Ki Keum, Yasuyuki Tanaka, Yoshiki Chujo
    2004 Volume 77 Issue 4 Pages 827-833
    Published: 2004
    Released: April 02, 2004
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    Crystallization of CaCO3 with in-situ radical polymerization of sodium acrylate in aqueous solution was carried out by a double jet method to prevent heterogeneous nucleation at glass walls. The concentration of sodium acrylate was 1.71 mM and the feed ratio of sodium acrylate to calcium ions was 0.62. After addition of the calcium reactants into the aqueous solution of sodium acrylate was completed, an aqueous solution of potassium peroxodisulfate as a water-soluble radical initiator was added to the reaction mixture after incubation at 30 °C for several minutes (1, 3, or 20 min). Three different crystal polymorphs of CaCO3 (aragonite, vaterite, and calcite) were selectively induced by changing the time for adding the radical initiator to a calcium carbonate solution with sodium acrylate. Formation of crystalline CaCO3 in the presence of sodium acrylate with the radical initiator at different feed ratio of sodium acrylate to calcium ions was also studied. The higher concentration of sodium acrylate increased sizes of vaterite spherical particles. The present results indicate that the final crystalline phases are highly sensitive to the presence of the active additives at the very initial nucleation stage (within several minutes).
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