Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
Volume 72 , Issue 1
Showing 1-20 articles out of 20 articles from the selected issue
  • Kikuo Miyokawa, Eugene Tschuikow-Roux
    Type: Article
    Subject area: TP
    1999 Volume 72 Issue 1 Pages 1-5
    Published: 1999
    Released: September 01, 2003
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    The kinetics of the α-H abstraction reaction RH + Br → R + HBr, RH = 1,1-dichloro (1) and 1,1-dibromoethane (2) was investigated in the temperature range 308—368 K using chloroethane and ethane as an external competitor, respectively. The relative rates were combined with the known rate parameters for chloroethane and ethane to obtain the absolute rate constants (cm3 mol−1 s−1): k1 = [6.9 ± 3.8(σ)] × 1011exp[(−7300 ± 360 cal mol−1)/RT] and k2 = [2.2 ± 1.2(σ)] × 1011exp[(−7110 ± 360 cal mol−1)/RT]. Using a justifiable approximation concerning the magnitude of the activation energies for the reverse reaction, the following thermochemical quantities (kcal mol−1) were derived: ΔH°f(CH3CCl2) = 11.9 ± 1.2, D°(CH3CCl2-H) = 95.1 ± 1.2, ΔH°f(CH3CBr2) = 33.5 ± 1.3, D°(CH3CBr2-H) = 94.9 ± 1.2. The relation between the reaction thermochemistry and the reactivity in chlorination and bromination of haloethanes is discussed.
  • Jun-ichi Aihara
    Type: Article
    Subject area: TP
    1999 Volume 72 Issue 1 Pages 7-11
    Published: 1999
    Released: September 01, 2003
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    Isolable fullerene isomers must be kinetically very or fairly stable. It was found that both the minimum bond resonance energy (min BRE) and the highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) energy separation are useful for estimating the kinetic stability of fullerene molecules. A fullerene isomer must be difficult to isolate from the arc-produced soot if it has a min BRE of less than −0.100 |β| and/or a HOMO-LUMO energy separation smaller than 0.130 |β|. All fullerene isomers so far isolated are kinetically stable in this sense. Candidates for isolable fullerene isomers were chosen by evaluating these two indices.
  • Shinsaku Fujita
    Type: Article
    Subject area: TP
    1999 Volume 72 Issue 1 Pages 13-20
    Published: 1999
    Released: September 01, 2003
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    The characteristic monomial table of an achiral group is applied to combinatorial enumeration of the following types: (1) achiral isomers and enantiomeric pairs, (2) achiral isomers and chiral isomers, (3) enantiomeric pairs, and (4) achiral isomers. The cycle index of each case is obtained by using the same set of subduced cycle indices derived from characteristic monomials, where the coefficients of the subduced cycle indices are given in advance.
  • Tasuku Fujinawa, Hirotoshi Goto, Toshio Naito, Tamotsu Inabe, Tomoyuki ...
    Type: Article
    Subject area: TP
    1999 Volume 72 Issue 1 Pages 21-26
    Published: 1999
    Released: September 01, 2003
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    Two polymorphs of 1 : 1 charge-transfer complexes of DAP–BRL were grown from a benzene solution. The γ-form is triclinic, space group P1-, a = 16.53(1), b = 17.80(1), c = 8.235(5) Å, α = 96.42(7), β = 97.76(6), γ = 120.79(5)°, V = 2015(3) Å3, and Z = 4; the δ-form is monoclinic, space group Pn, a = 6.862(3), b = 9.891(2), c = 15.246(2) Å, β = 101.78(2)°, V = 1012.9(5) Å3, and Z = 2. Both crystals comprise mixed stacks of donors and acceptors. The molecular geometry, the CO stretching frequencies, and the EPR spectra indicate that most of the component molecules in both crystals are in the neutral state. The electrical conductivity is, however, found to be high; especially the value for γ-DAP–BRL (10−1Ω−1 cm−1) is unusually high as a neutral mixed-stack complex.
  • Yoshinari Konishi, Pichai Maruthamuthu, Masaharu Okazaki, Youko Arakaw ...
    Type: Article
    Subject area: TP
    1999 Volume 72 Issue 1 Pages 27-31
    Published: 1999
    Released: September 01, 2003
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    The effects of microwaves (MW) on the photolysis of a benzene solution of N-[12-(4-nitro-1-naphthyloxy)dodecyl]aniline under a magnetic field were investigated. The reaction intermediate was identified as a biradical the ESR spectrum of which was recorded by plotting the MW effect as a function of the magnetic field under which the reaction proceeds. The kinetic parameters of the reaction system were estimated from the MW effects observed as functions of the delay period from the laser pulse for putting on/off the MW pulse.
  • Balasubramanian Kalyanasundari, Krishnaswamy Panchanatheswaran, Virara ...
    Type: Article
    Subject area: AI
    1999 Volume 72 Issue 1 Pages 33-36
    Published: 1999
    Released: September 01, 2003
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    Phenacylidenetriphenylphosphorane reacts with HgI2 in 2 : 3 molar ratio to form a novel trinuclear iodobridged symmetrical complex whose structure has been elucidated by IR, multinuclear NMR, and X-ray crystallography. The Hg···Hg distance [3.648(1) Å] indicates a negligible bonding interaction between the mercury atoms.
  • Toshiaki Hattori, Kazuhito Katai, Masanao Kato, Masato Izume, Youichi ...
    Type: Article
    Subject area: AI
    1999 Volume 72 Issue 1 Pages 37-41
    Published: 1999
    Released: September 01, 2003
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    Three sorts of characterized chitosan were measured by visual titration and potentiometric titration with poly(vinyl sulfate) using Toluidine Blue as the indicator, to evaluate the stoichiometry and the accuracy. The measurement values for two dialyzed chitosans by both colloidal titration methods agreed with the values obtained by the acid-base titration. The relative differences between the acid-base titration and the colloidal titration were < 2%, and the relative standard deviation of the potentiometric colloidal titration was < 1%. For a oligo-chitosan (ChO) which consisted of several D-glucosamine oligosaccharides, the value obtained by the potentiometric colloidal titration was much smaller than the value from the acid-base titration. The inadequate result was due to the low stability constant of ChO–PVS. The observed values in the colloidal titration of ChO were evaluated for the content of each D-glucosamine oligosaccharide, and a critical unit that indicated the least unit of D-glucosamine oligosaccharide that contributed to the measurement value was estimated. The critical unit was four, tetra(D-glucosamine saccharide).
  • Tokuo Shimizu, Hirobumi Ito, Hiroshi Kawaguchi, Yoshio Shijo
    Type: Article
    Subject area: AI
    1999 Volume 72 Issue 1 Pages 43-46
    Published: 1999
    Released: September 01, 2003
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    Miniaturized coprecipitation with hydrous manganese(IV) oxide was studied for the preconcentration of sub μg dm−3 levels of molybdenum in water samples. Manganese(IV) oxide was produced by a reaction of permanganate ion with ethanol in the presence of 0.1 mol dm−3 hydrochloric acid. A nanogram amount of molybdenum in a 10 cm3 sample was quantitatively coprecipitated. The amount of manganese required was 0.1—0.40 mg for a 10 cm3 sample. The precipitate was collected on a 10 μm membrane filter, and then dissolved in 50 mm3 of 5.6 mol dm−3 nitric acid and 75 mm3 of 1% hydrogen peroxide. An 80-fold preconcentration factor was obtained by this procedure. The molybdenum concentration was determined by electrothermal atomic absorption spectrometry using a pyrolytic graphite coated cuvette. The detection limit (3σ) was found to be 8.9 ng dm−3. The proposed method was successfully applied to river water and snow samples.
  • Jun Kawakami, Toshiaki Furuta, Junko Nakamura, Akira Uchida, Michiko I ...
    Type: Article
    Subject area: OB
    1999 Volume 72 Issue 1 Pages 47-54
    Published: 1999
    Released: September 01, 2003
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    Two kinds of model compounds for a bichromophoric ester, 2-(1-pyrenyl)ethyl p-cyanobenzoate (P2CN), were synthesized: 1-substituted 2-(1-pyrenyl)ethyl p-cyanobenzoates (RP2CN, R = Me, Et, and Ph) as flexible model compounds and trans-2-(1-pyrenyl)cyclohexyl p-cyanobenzoate (cyclo-P2CN) as a rigid model compound. P2CN and all the model compounds had an intramolecular exciplex emission (φEX ≈ 0.010) and efficient quenching of fluorescence from the locally excited pyrene part (φLE ≈ 0.001). The decay lifetimes of the locally excited pyrene were 365 ps for P2CN and 66 ps for cyclo-P2CN, which were respectively identical with the risetime for the exciplex formation. The 1H NMR of both P2CN and RP2CN showed the shifts of H2″ and H3″ of the p-cyanobenzoyl to the higher and H10′ of 1-pyrenyl signals to the lower magnetic field compared with those of the reference compounds, approaching towards those of cyclo-P2CN. NOE was observed between H10′ and H2″ of cyclo-P2CN, and, although very weak, between H2′ and H3″ of MeP2CN. In the solid state, P2CN adopts a folded conformation, which is roughly close to the gauche conformation, with the dihedral angle of 57.5° between p-cyanophenyl ring and pyrenyl ring based on X-ray crystallographic analysis on a leaflet monoclinic crystal, suggesting the exciplex formation from this conformation in P2CN.
  • Yoshihito Inai, Yuji Kurokawa, Atushi Ida, Tadamichi Hirabayashi
    Type: Article
    Subject area: OB
    1999 Volume 72 Issue 1 Pages 55-61
    Published: 1999
    Released: September 01, 2003
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    To understand the effects of N-terminal L-residues on dominating helical screw sense in achiral peptides, we adopted six kinds of peptides Boc–X–(Aib–ΔPhe)2–Aib–OMe (Boc, t-butoxycarbonyl; OMe, methoxy), in which the X residue is an L-amino acid of alanine (Ala), leucine (Leu), valine (Val), phenylalanine (Phe), 1-naphthylalanine (Nap), or proline (Pro). The segment –(Aib–ΔPhe)2– was used for a backbone composed of two “enantiomeric” (left-/right-handed) helices. Actually, this could be confirmed by 1H NMR and CD spectroscopy on Boc–(Aib–ΔPhe)2–Aib–OMe, which took left- and right-handed 310-helices with the same content. All peptides were also found to take 310-type helical conformations in CDCl3 from solvent accessibility of NH resonances. Chloroform, acetonitrile, methanol, and tetrahydrofuran were used for solvents in CD measurement. All peptides in all solvents showed marked exciton couplets around 280 nm with a positive peak at longer wavelengths. Consequently, when an N-terminal L-residue, irrespective of types of L-residues, is introduced into a helical segment of achiral peptide, its main chain prefers the left-handed screw sense. The peptide with X = Alashowed the smallest amplitude of exciton couplets in each solvent, meaning that the Ala residue with the smallest side chain (methyl group) had the least effective chirality for taking a one-side helical screw sense preferentially, compared with the other residues used here.
  • Michinori Oki, Takanori Hirose, Yasukazu Kataoka, Taisuke Ogata, Shinj ...
    Type: Article
    Subject area: OB
    1999 Volume 72 Issue 1 Pages 63-72
    Published: 1999
    Released: September 01, 2003
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    Reactions of p-toluenesulfenyl chloride with the title olefins in carbon tetrachloride afforded an addition product and sp-1-(9-fluorenyl)-2-[1-(p-tolylthiomethyl)ethenyl]naphthalene in the case of ap, whereas the only product was ap-1-(9-fluorenyl)-2-[1-(p-tolylthiomethyl)ethenyl]naphthalene in the case of sp. No cyclized compounds, which are commonly observed in the reactions of the sp-isomer with halogens or halogen chloride, were detected. Various unsuccessful attempts, including use of methanesulfenyl chloride to take advantage of different sulfur acidity, use of a soft anion to retard deprotonation or a polar solvent to accelerate cyclization by stabilizing the intervening cations, have been made to find conditions for formation of the cyclized compound. Similar unsuccessful results were obtained with benzeneselenenyl halides. Such results are attributed to the effective participation of a chalcogen atom in stabilizing a β-carbocation, which opens momentarily but is less vulnerable to the SN2 type attack of the existing nucleophile. Coloration was observed in the reaction of the sp form with methanesulfenyl chloride.
  • Kedar Shanker Shrestha, Kiyoshi Honda, Masatoshi Asami, Seiichi Inoue
    Type: Article
    Subject area: OB
    1999 Volume 72 Issue 1 Pages 73-83
    Published: 1999
    Released: September 01, 2003
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    A simple and facile synthesis of the fused 6-6-5 ring system, i.e., 1,2,3,3a,4,9b-hexahydrocyclopenta[c][1]benzopyrans, was achieved through the intramolecular [4+2] cycloaddition of o-quinonemethides generated from 2-(1-hydroxy-5-alkenyl)phenol derivatives under acidic conditions. In general, cis-fused tricyclic compounds of 6-6-5 ring system were obtained as the major products. Reactivity and selectivity of the cycloaddition reaction depended on the substituents on the aromatic ring and in the dienophilic olefin moiety.
  • Nobuharu Iwasawa, Masahiro Funahashi, Satoshi Hayakawa, Taketo Ikeno, ...
    Type: Article
    Subject area: OB
    1999 Volume 72 Issue 1 Pages 85-97
    Published: 1999
    Released: September 01, 2003
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    Bicyclic cyclopropanols having an olefinic side chain are oxidized with manganese(III) tris(pyridine-2-carboxylate) to generate cyclic β-keto radicals with ring-expansion. These cyclize intramolecularly, affording bicyclic radical intermediates. The cyclized radicals are trapped with various radical-trapping reagents such as electron-rich or -deficient olefins, tributylstannane and diphenyl diselenide to give the corresponding functionalized products. Stereochemistries of the bicyclic products are well predicted by MM2 force field calculation. A stereoselective total synthesis of an isothiocyano sesquiterpene, 10-isothiocyanatoguaia-6-ene, is achieved using this reaction.
  • Yasushi Kawai, Kouichi Hida, Munekazu Tsujimoto, Shin-ichi Kondo, Kazu ...
    Type: Article
    Subject area: OB
    1999 Volume 72 Issue 1 Pages 99-102
    Published: 1999
    Released: September 01, 2003
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    Optically pure α-hydroxy esters and α-hydroxy ketones have been synthesized by the reduction of the corresponding ketones with a keto ester reductase isolated from bakers’ yeast (YKER-I). The reduction of α-keto esters affords the corresponding (S)- or (R)-hydroxy esters selectively, where the stereochemical course depends on the chain length of the alkyl substituent on the carbonyl group. An α-keto short alkanoic ester affords the corresponding (S)-hydroxy ester, whereas a long alkanoate yields the corresponding (R)-hydroxy ester. The reduction of α-diketones affords the corresponding (S)-2-hydroxy ketones regio- and stereoselectively.
  • Itsuko Suzuki, Ryoko Tanaka, Akinori Yamaguchi, Shin-ichiro Maki, Hiro ...
    Type: Article
    Subject area: OB
    1999 Volume 72 Issue 1 Pages 103-113
    Published: 1999
    Released: September 01, 2003
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    The reaction course of acyl-diphenylmethyl biradicals (α-oxo-ω,ω-diphenyl-α,ω-alkanediyl biradicals), O=C–(CH2)n−2–CPh2 (3BR-n), generated from the Norrish type-I reaction of 2,2-diphenylcycloalkanones (CK-n) with various ring sizes in methanol, is switched from intramolecular disproportionation (n = 6, 7), giving a diphenylalkenal, to acyl-phenyl recombination (n ≥ 9), affording a cyclophane derivative. The behavior of 3BR-9 derived from CK-9 was studied in detail; the photolysis of CK-9 afforded an open-chain and a cyclic decarbonylation product together with an unsaturated aldehyde and a 4-methylene-2,5-cyclohexadienyl ketone (a pre-cyclophane). The photolysis of this ketone gave the same products that arose from the photolysis of CK-9, presenting the possibility that the decarbonylation products and a part of the aldehyde are formed as secondary products during irradiation.
    The magnetic field dependence of the lifetimes of 3BR-n (n = 12 and 13) generated from CK-12 and 13, respectively, was measured in methanol by means of a pulsed-laser excitation technique. The rate constants for intersystem crossing showed a maximum at a relatively low field strength, which decreased with increasing the field strength to level off to an asymptotic value at > 1.5 kG. The results show that the role of hyperfine coupling in intersystem crossing is less important in these systems, presumably because of the presence of a carbonyl oxygen and the absence of a hydrogen atom at the radical center.
  • Piotr Lulinski, Lech Skulski
    Type: Article
    Subject area: OB
    1999 Volume 72 Issue 1 Pages 115-120
    Published: 1999
    Released: September 01, 2003
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    Novel and easy laboratory methods (novel Procedures 14) are presented for the oxidative mono- and diiodination of both activated and deactivated arenes, which gave the pure iodinated products in 62—89% yields. The reactions were carried out in the anhydrous, strongly acidic system, I2/activated MnO2/AcOH/Ac2O/concd H2SO4, firstly at r.t. for 2 h, then at 45—55 °C for 2—9 h. The resulting mixtures were poured into excess aq Na2SO3 solution buffered with (NH4)2CO3 to neutralize H2SO4. The following workups are given. Similarly, on carrying out the iodination reactions (at 35 °C, for one hour) in the anhydrous, strongly acidic system, I2/KMnO4/AcOH/Ac2O/concd H2SO4, it was possible to mono- or diiodinate several deactivated arenes in 73—87% yields (improved Procedures 5 and 6).
  • Hitoshi Inoue, Kazuyuki Satoh
    Type: Article
    Subject area: AM
    1999 Volume 72 Issue 1 Pages 121-126
    Published: 1999
    Released: September 01, 2003
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    An osmium-oxygen thin film was prepared by d.c.-glow-discharge deposition from osmium tetraoxide with a filming rate of 1 nm s−1. The fundamental properties of the films were investigated. The prepared films had a homogeneous amorphous structure and 10−4 Ω cm order of resistivity. Since the transparency of a 20 nm thick film was about 80% for visible light, a transparent conductive film could be obtained on glass or plastic substrates. X-Ray photoelectron spectroscopy measurements showed that the film contained 30 at.% of osmium and 70 at.% of oxygen, which might make the film be easily etched by an oxygen-plasma, or be electrically oxidized. Since the osmium film could be patterned by oxygen-plasma etching or by a lift-off method, which are familiar lithography techniques in the field of semiconductor devices, it is expected to be used as micro-electrode or micro-wiring materials. Low-temperature film preparation also makes it possible to be applied as an X-ray mask material for X-ray lithography.
  • Masaki Matsui, Mitsugu Kushida, Kazumasa Funabiki, Hiroshige Muramatsu ...
    Type: Article
    Subject area: AM
    1999 Volume 72 Issue 1 Pages 127-132
    Published: 1999
    Released: September 01, 2003
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    The in situ prepared polyurethane films of the thiazolylazo NLOphores showed d33values of 38—49 pm V−1. The temporal stability of the poled NLOphore was in the following order of the polymers: network > side chain > main chain.
  • Yasutake Teraoka, Wengfeng Shangguan, Kjell Jansson, Mats Nygren, Shui ...
    Type: Article
    Subject area: AM
    1999 Volume 72 Issue 1 Pages 133-137
    Published: 1999
    Released: September 01, 2003
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    The oxide catalyst having an overall metal composition of La/K/Cu/V = 9/1/7/3 (denoted as LKCVO) showed an excellent selectivity to NOx reduction into N2 in the simultaneous NOx-soot removal reaction, though it was a mixture of several crystalline phases. In order to identify the real active phase, LKCVO was characterized by X-ray diffraction (XRD) and by elemental analysis of individual grains in a transmission electron microscope (TEM) equipped with an energy dispersive spectrometer (EDS). LKCVO was found to be composed of CuO and mixed metal oxides analogous to La2CuO4, LaVO4, and La3VO7. By comparing the catalytic activity of LKCVO with those of single-phase oxides synthesized according to the results of XRD and TEM/EDS, (La2−xKx)(Cu0.95V0.05)O4 with 0.05 ≤ x ≤ 0.1 was identified to be the real active phase in LKCVO for the simultaneous NOx-soot removal reaction.
  • Keiichi Tsukahara, Junko Kaneko, Tomoko Miyaji, Kaya Abe, Maki Matsuok ...
    Type: Article
    Subject area: AM
    1999 Volume 72 Issue 1 Pages 139-149
    Published: 1999
    Released: September 01, 2003
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    Optically active viologens, containing [1-(1-naphthyl)-, 1-phenyl-, and 1-cyclohexylethyl]carbamoylmethyl groups, have been synthesized and characterized. The redox behavior of the chiral viologens was studied compared with achiral viologens. The monoviologens containing naphthyl groups show an intermolecular charge-transfer interaction between the bipyridinium and naphthyl groups in aqueous solution. The association constants are dependent on the chirality of the viologens and larger in the (S,S)- and (R,R)-isomers than in the (R,S)-one. Chiral bisviologens, in which two viologen units are linked with a trimethylene chain, have also been synthesized and characterized. Although the intermolecular charge-transfer interaction between the bipyridinium and viologen units of bisviologens was very weak in solution, such an interaction was appreciably observed in a solid state, which was confirmed by X-ray crystallography. Monoradical trications produced by a one-electron reduction of bisviologens disproportionate more easily in the (R,S)-isomers than in the (S,S)- and (R,R)-ones. The disproportionation is controlled by the steric bulk of the chiral substituents in intramolecular association between two viologen radical units of diradical dications.
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