Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
Volume 69 , Issue 12
Showing 1-38 articles out of 38 articles from the selected issue
  • Masud S. Huda, Katsuhiko Fujio, Yuhei Uzu
    1996 Volume 69 Issue 12 Pages 3387-3394
    Published: 1996
    Released: June 29, 2006
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    The phase behaviors of the monohydroxy- and dihydroxy-substituted fatty acids at an air–water interface were investigated in the presence of different substrates. All of the hydroxylated fatty acids studied, except for 2-hydroxyoctadecanoic acid (2-HOA) and 9,10-dihydroxyoctadecanoic acid (9,10-DHOA), showed an intermediate region (“plateau”) for a transition from a liquid-expanded state (LE) to a liquid-condensed state (LC) in the π–A isotherms, regardless of the substrate composition. In contrast, 9,10-DHOA exhibited a pressure plateau region on only 3 M NaCl. In order to assess the effect of adding an extra polar group (i.e., a hydroxy group) for a 9,10-DHOA monolayer compared to a 9-hydroxyoctadecanoic acid (9-HOA) monolayer, the monolayer-substrate interactions were considered based on the thermodynamic parameters for the LE/LC phase transition, using a two-dimensional Clausius–Clapeyron equation. This can be explained by assuming that a greater energy was generated for breaking of hydrogen bonds between the two hydroxy groups of 9,10-DHOA and water. In this regard, the dynamic properties of the monolayer for these acids were examined using the surface pressure relaxation method as well as an equilibrium spreading pressure (ESP) measurement.
  • Yasunori Yoshioka, Daisuke Yamaki, Goro Maruta, Tsunaki Tsunesada, Kaz ...
    1996 Volume 69 Issue 12 Pages 3395-3415
    Published: 1996
    Released: June 29, 2006
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    A systematic MO-theoretical description of electronic structures of tricentric bisdesmiphiles in the ground state is presented in response to contradictory arguments on the biradical character of the species by Huisgen, Firestone, and others. The approximately spin-projected but size-consistent (AP) UHF and UMP methods remedy artifact arising from the spin contamination effect involved in the singlet UHF and UMP wavefunctions, giving reasonable a different-orbitals-for-different-spins (DODS) MO description for oxygenated dipoles such as O3 and CH2OO and 1,3-biradicals without octet stabilization such as OCH2O and CH2CH2CH2. The RHF method provides well-accepted MO description for diszonimum and nitrilium betaines having little biradical character, and the RMP method works well even for species with weak biradical character. They are successfully applied to calculating relative energies between nonradical ring- and biradical open-forms of tricentric species, singlet–triplet energy gaps of tricentric biradicals, and high- and low-spin energy gaps of polyradicals constructed of 1,3-biradical units. Reliability of the projected UHF and UMP scheme for biradical species was confirmed by the complete active space (CAS) configuration interaction (CI) by the use of UHF natural orbitals (UNO). The UNO CASCI calculations are also carried out both for the ground and excited of 1,3-biradicals. The energy gradient technique based on UNO CASSCF is applied to the full geometry optimizations of tricentric systems, followed by the UNO CASSCF MP2 calculations for dynamical correlation corrections. On the other hand, the UNO MR SDCI method by the use of the UNO CASCI reference gives a well-balanced MO-theoretical description of the ground and excited states. Comparisons of different definitions of biradical character are given in relation to theoretical explanations of 1,3-dipoles and 1,3-dipolar reactions. It is shown that the present MO-theoretical description based on both delocalized and localized natural orbitals is wholly compatible with experimental data obtained by Huisgen and others.
  • Kallol Kumar Ghosh, Supriya Roy
    1996 Volume 69 Issue 12 Pages 3417-3422
    Published: 1996
    Released: June 29, 2006
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    The kinetics of alkaline hydrolysis of N-phenylbenzohydroxamic acid and its para-substituted derivatives (X–C6H4–CO–N(OH)C6H5; X = H, CH3, OCH3, NO2, F) have been investigated in the presence and absence of cationic (ethyl hexadecyl)dimethylammonium bromide) and anionic (sodium-1-dodecanesulfonate and lithium dodecyl sulfate) surfactants at 55 °C in 5% (v/v) dioxane–water medium. A catalytic effect was found with cationic surfactants and an inhibitory effect in the presence of anionic surfactants was observed. The rate-surfactant profiles can be analyzed in terms of pseudo-phase and Piszkiewicz models.
  • Xing-Zheng Wu, Hideki Kitatani, Katsumi Uchiyama, Toshiyuki Hobo
    1996 Volume 69 Issue 12 Pages 3423-3428
    Published: 1996
    Released: June 29, 2006
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    In order to improve the detection sensitivity of the reaction heat-induced optical beam deflection method, the experimental factors that affect the detection sensitivity were investigated in detail. Firstly, different types of deflection detectors were compared. The experimental results showed that the bi-cell photodiode detector is most sensitive to the deflection signal. Secondly, the effect of the size of the reaction cell on the detection sensitivity was investigated. A small reaction cell gave a stable baseline and small noise in flow injection experiments, and thus gave a high detection sensitivity. Thirdly, the effects of the optical arrangements on the detection sensitivity were investigated. Focusing the probe beam close to the gold film/CCl4 interface enhanced the detection sensitivity. Also, refocusing the deflected probe beam improved the sensitivity. Under the selected experimental conditions, the detection of the neutralization reaction between HCl and NaOH at sub-nanomol level became possible. Further improvements are also discussed.
  • Masakazu Makino, Mamoru Kamiya, Toshio Ishii, Kenichi Yoshikawa
    1996 Volume 69 Issue 12 Pages 3429-3434
    Published: 1996
    Released: June 29, 2006
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    We measured the time-dependent surface pressure of a dioleoylphosphatidylcholine film at an air/water interface. Our results indicate that: (i) the surface pressure of the thin film traces a closed hysteresis loop accompanied by repetitive cycles of compression and expansion, and (ii) the area of the hysteresis loop markedly increases in the presence of sodium ions. We propose a kinetic model for this phenomenon which includes cooperative aggregation/dissociation at the air/water interface. The experimental findings have been successfully reproduced with the aid of a computer simulation based on this theoretical model.
  • Hisahiro Einaga, Makoto Misono
    Type: Accounts
    Subject area: AI
    1996 Volume 69 Issue 12 Pages 3435-3441
    Published: 1996
    Released: June 29, 2006
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    Photocatalytic properties of PW12O403− (abbreviated as PW123−) for the 4-chlorophenol (4-CP) decomposition was investigated by using a 300 W Xe lamp at 35 °C in aqueous media. The rate of the 4-CP decomposition was not influenced by pH in the range from 1.0 to 2.0, where PW123− is stable. In the dark, no reaction proceeded. When the photolysis was carried out under O2 atmosphere, 4-CP was decomposed and the catalyst remained in the oxidized form. In the deaerated solution, PW123− was reduced to PW12O404− (PW124−) by irradiation, the amount of PW124− formed during irradiation being approximately identical with the amount of 4-CP concurrently consumed. When the irradiation was stopped and O2 was introduced, PW124− was oxidized rapidly to PW123− and a small amount of 4-CP decomposed.
    Based on these facts we deduced that the reaction consists of the following three steps: (1) photoexcitation of PW123−, (2) one-electron reduction of the excited PW123− to PW124− with simultaneous oxidation of 4-CP, and (3) reoxidation of PW124− to the original form by O2. 4-CP is also decomposed in the last step, although the amount is much smaller than that in step (2). The dependency of the reaction rates on the concentration of substrate was explained by Langmuir (or Michaelis Menten) type kinetics, indicating that the complex formation between PW123− and 4-CP is the indispensable step of the photocatalytic decomposition.
  • Kazunari Yoshizawa, Takako Kuga, Tohru Sato, Masashi Hatanaka, Kazuyos ...
    Type: Accounts
    Subject area: AI
    1996 Volume 69 Issue 12 Pages 3443-3450
    Published: 1996
    Released: June 29, 2006
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    Through-bond and through-space magnetic interactions in tricarbene and its related triradicals coupled through m-phenylene units are discussed with a semiempirical molecular orbital method including configuration interactions (PM3-CI method). The high-spin (HS) and low-spin (LS) states have quite similar geometries, but the methylene bridging angle is larger in the HS states. The HS states of these lie well below the corresponding LS states, except for one which contains nitroxide and aminiumyl radicals. Instability of the HS state of the heteroatomic system is a consequence of significant mixing between NBMOs and benzene e1g-type orbitals, which can be explained in terms of simple perturbation theory. The energy difference between the HS and LS states is not explicitly influenced by the conformation of the molecules examined. This shows that such conformations have little effect on the magnetic properties in possible polymer ferromagnets which contain m-phenylene coupling units, as far as the second nearest neighbor interaction.
  • Yoshinori Kobayashi, Kouichi Hirata
    Type: Accounts
    Subject area: AI
    1996 Volume 69 Issue 12 Pages 3451-3454
    Published: 1996
    Released: June 29, 2006
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    The magnetic quenching of ortho-positronium (o-Ps) has been studied for various solutions of nitrobenzene and 1,3-dimethyl-2-nitrobenzene. Static magnetic fields were applied to the solutions and the average o-Ps lifetimes were measured as a function of the field strength up to 1 T. Anomalous magnetic quenching, similar to that observed for nitrobenzene in hexane, was found for solutions of nitrobenzene in isopentane, pentane, diethyl ether and heptane as well as 1,3-dimethyl-2-nitrobenzene in dodecane and toluene. It is suggested that o-Ps detached from a weakly bound complex between positronium (Ps) and the nitrocompound may be responsible for the anomalous effect.
  • Kazuo Kasatani, Hiroyasu Sato
    1996 Volume 69 Issue 12 Pages 3455-3460
    Published: 1996
    Released: June 29, 2006
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    The lifetimes of the short-wavelength (SW) fluorescence of some cyanine dyes with 3, 5, and 7 methine units were measured using a synchronously pumped picosecond dye laser in conjunction with the time-correlated single-photon counting method. The lifetimes were longest for dyes with 5 methine units, and decreased in the order of 5, 7, and 3 methine units. The lifetimes were highly dependent on the solvent viscosity. The dependences were compared with those of the fluorescence quantum yields previously reported by the authors in order to determine the relative importance of direct internal conversion (viscosity-independent) relaxation channel and that of the crossing-over to the photoisomer potential energy curve (viscosity-dependent channel). It was determined that origin of the SW fluorescence was the second excited singlet state by semiempirical molecular orbital calculations. The absolute SW fluorescence quantum yield of one of the cyanine dyes, DODC, was found to be less than 0.002 in ethanol. The relaxation rates of these cyanine dyes in the first and second excited singlet states were compared.
  • Takakazu Yamamoto, Takehiro Matsuzaki, Akiyuki Minetomo, Yoichi Kawazu ...
    Type: Accounts
    Subject area: AI
    1996 Volume 69 Issue 12 Pages 3461-3468
    Published: 1996
    Released: June 29, 2006
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    Plantinum electrodes modified with 10 kinds of π-conjugated polymers have been prepared. These polymers include poly(pyridine-2,5-diyl) PPy, poly(2,2′-bipyridine-5,5′-diyl) PBpy, poly(3-octylthiophene-2,5-diyl) P3OcTh, and poly(6-hexylpyridine-2,5-diyl) P6HexPy. Films of PPy and PBpy behave as good H+-transporting materials in 0.5 M H2SO4 (aq). Plots of log i vs. V for electrodes modified with the polymers give linear lines in a current density region of 10−5.5—10−2 A cm−2. The slope of the line, β = dV/d(log i), depends on the kind of the polymer. Hydrophilic PPy and PBpy give a β value of 3.2 × 10−2 V, while hydrophobic P3OcTh and P6HexPy with long alkyl chains give a larger β value of 4.5 × 10−2 V. Diffusion coefficients of H+ in films of PPy, PBpy, and poly(quinoline-2,6-diyl) P(2,6-Q) are estimated to be larger than 10−7 cm2 s−1 from limiting currents at room temperature. The iV curve of a P(2,6-Q)-modified Pt electrode shows a strong pH-dependence reflecting a chemical change of the polymer with pH. The PPy-, PBpy-, and P3OcTh-modified Pt electrodes exhibit acceleration effects for evolution of O2 from 1 M KOH (aq).
  • Akihide Itoh, Chisen Kimata, Hajime Miwa, Hideyuki Sawatari, Hiroki Ha ...
    1996 Volume 69 Issue 12 Pages 3469-3473
    Published: 1996
    Released: June 29, 2006
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    An on-line separation-detection system, liquid chromatography coupled with inductively coupled plasma mass spectrometry (ICP-MS), has been developed and applied to the study on speciation of trace metals in pond water. First, the total concentrations of dissolved metal ions in pond water were determined by ICP-MS after chelating resin preconcentration. Then, pond water was preconcentrated by ultrafiltration using a filter with a molecular weight permeation limit of 10000, providing size exclusion chromatography. Large organic molecules which had combined with trace metals in the preconcentrated samples were separated with a gel filtration column and detected by UV absorption and ICP-MS, sequentially. In consequence, large organic molecules with the molecular weight of ≥300000 and 10000—50000 could be observed. A large number of trace metals (41 elements) were found in those organic molecules. Furthermore, the percentages of metal ions in the forms of large organic molecule–metal complexes were estimated from their concentrations as determined by the flow injection method.
  • Santanu Bhattacharya, Pradyot Banerjee
    Type: Accounts
    Subject area: AI
    1996 Volume 69 Issue 12 Pages 3475-3482
    Published: 1996
    Released: June 29, 2006
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    In aqueous solution at 30 °C, azide is oxidized to N2 by [NiIV(L1)2]2+ and [NiIV(L2)]2+ (where HL1 = 6-amino-3-methyl-4-azahex-3-en-2-one oxime and H2L2 = 3,14-dimethyl-4,7,10,13-tetraazahexadeca-3,13-diene-2,15-dione dioxime). The reaction is of overall second order, first order in both [N3] and [NiIV] and exhibits a strong dependence on [H+] of the medium. In the range 2.0 ≤ pH < 6.0 for [NiIV(L1)2]2+ and 2.0 ≤ pH < 4.5 for [NiIV(L2)]2+ single step two-electron transfer reactions are encountered, whereas a distinct biphasic process with initial faster step of NiIV → NiIII conversion followed by a second slower step of NiIII → NiII reduction was observed in the range 6.0 ≤ pH ≤ 8.0 and 4.50 ≤ pH ≤ 8.0 for the respective oxidants. The bell-shaped pH-rate profile for the reduction of Ni(IV) → Ni(III) step confirms the involvement of an ‘outside’ protonated Ni(IV)-complex as a kinetic intermediate. All the kinetic parameters have been evaluated and the mechanism of the reaction is discussed. Application of Marcus cross-reaction relations shows that the reaction of [NiIV(Lx)]2+ and N3 follows an outer-sphere mechanism, but the reduction of [NiIII(Lx)]+ may differ from this path.
  • Makoto Handa, Masahiro Mikuriya, Yuka Sato, Takanori Kotera, Ryoji Nuk ...
    Type: Accounts
    Subject area: AI
    1996 Volume 69 Issue 12 Pages 3483-3488
    Published: 1996
    Released: June 29, 2006
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    A series of chain complexes of rhodium(II) trifluoroacetate, [Rh2(O2CCF3)4(p-Q)]n (p-Q = 1,4-benzoquinone (1,4-bq), 1,4-naphthoquinone (1,4-nq), and 2,3-dimethyl-1,4-benzoquinone (2,3-dmbq)) have been prepared. The chain structures were confirmed by the X-ray structure analyses. The carbonyl oxygens of the p-quinones are coordinated to the Rh2 centers with the distances of 2.248(5) (for p-Q = 1,4-bq), 2.248(3) (for p-Q = 1,4-nq), and 2.247(9) Å (for p-Q = 2,3-dmbq), respectively. The bridging mode of the p-quinone was discussed in relation to the substituent effect of CF3 group on the carboxylate.
  • Masahiro Mikuriya, Hideyuki Tsutsumi, Ryoji Nukada, Makoto Handa, Yasu ...
    1996 Volume 69 Issue 12 Pages 3489-3498
    Published: 1996
    Released: June 29, 2006
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    A series of ten trinuclear heterometal complexes with 2-[(3-aminopropyl)amino]ethanethiol (HL), [(MAL2)2MB](ClO4)2·2dmac·2X ([MA, MB] = [Mn, Zn], [Mn, Cd], [Fe, Zn], [Fe, Cd], [Fe, Hg], [Co, Zn] [Co, Cd], [Ni, Zn], [Ni, Cd], [Ni, Hg]; dmac = N,N-dimethylacetamide, X = H2O or CH3OH), have been synthesized and characterized by infrared and electronic spectroscopies, temperature dependence of magnetic susceptibilities (80—300 K), and single-crystal X-ray diffraction technique. Each complex has a thiolato-bridged heterotrinuclear structure which shows a linear arrangement of Oh(MA)–Td(MB)–Oh(MA). The spectral and magnetic properties were discussed in relation to the crystal structures.
  • Concepcion S. Mendoza, Satsuo Kamata
    Type: Accounts
    Subject area: AI
    1996 Volume 69 Issue 12 Pages 3499-3504
    Published: 1996
    Released: June 29, 2006
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    Silver recovery from photographic fixing solutions can be performed by solvent extraction with thiuram disulfides. Tetramethylthiuram disulfide (TMTDS) was selected for further studies because it had the highest distribution ratio among the three extractants. Its selectivity for silver extraction from a thiosulfate medium and from an analytical photographic fixing solution were evaluated. A 1 : 1 silver(I)–TMTDS complex is formed. For a one-stage and one-hour silver(I) extraction process, a 96% recovery was obtained from an analytical fixing solution containing 1 g dm−3 silver(I), starting with a 0.02 M (1 M = mol dm−3) TMTDS solution. The possible extraction mechanism involves the reduction of TMTDS in the presence of thiosulfate ions, followed by chelation of the silver(I) with the reduced TMTDS. Effective stripping can be performed by using 3 M hydrochloric acid. By dilution of the fixing solution with water (1 : 1), and the use of 0.1 M TMTDS, recycling of the organic phase between the extraction and stripping stages for silver extraction can be achieved in a few times. The results for the analytical solutions were further shown to be applicable to a black and white photographic industrial solution.
  • Eiji Fujimori, Rong Wei, Hideyuki Sawatari, Koichi Chiba, Hiroki Harag ...
    Type: Accounts
    Subject area: AI
    1996 Volume 69 Issue 12 Pages 3505-3511
    Published: 1996
    Released: June 29, 2006
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    A discrete microsampling technique for multielement determination of trace elements by inductively coupled plasma mass spectrometry has been investigated for analyses of samples containing large amounts of matrix elements. In the technique, 100 μl of the sample solution was introduced into the plasma by using a six-way valve, and 10 elements were detected in peak hopping mode during a single mass range scan. As a result, a transient peak profile of the signal for each element was observed at each m/z position. The peak area measurement method was established for the quantitative analysis. The optimization of instrumental conditions and matrix effects in multielement determination were investigated in detail. The discrete microsampling technique was found to reduce some memory effects due to matrices in ICP-MS. The present system was applied to the analyses of standard sediment sample and 30 elements at the μg g−1 level were successfully determined without matrix separation.
  • Taku Nakano, Noriko Agatsuma, Shiori Kodama, Hiroko Kakuda, David Dolp ...
    1996 Volume 69 Issue 12 Pages 3513-3521
    Published: 1996
    Released: June 29, 2006
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    A mechanistic study of the oxidation of toluene and its derivatives in a model system designed to mimic cytochrome P450 (P450) using iron tetrakis(2,6-dichlorophenyl)porphyrin chloride (FeTPPCl8Cl) and pentafluoroiodosylbenzene (PFIB:C6F5IO) in dichloromethane is reported. The oxidation products were the corresponding benzyl alcohols and aldehydes; no further oxidation products were observed. The relative reaction rates were obtained in competitive reactions including the use of deuterated analogues. In the present model system, Hammett plots and isotope effects indicated conclusively that the rate-determining step was a hydrogen atom abstraction to the oxoiron intermediate which was then followed by a rebound of an OH group. The concerted mechanism and the rebound mechanism were discussed in terms of the differences in reactivities between the model system and natural P450 enzymes and similar monooxygenation enzymes.
  • Yasushi Matsumura, Toyomichi Shimada, Shu-Zhong Wang, Tomoyuki Asai, Y ...
    Type: Accounts
    Subject area: AI
    1996 Volume 69 Issue 12 Pages 3523-3531
    Published: 1996
    Released: June 29, 2006
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    New and facile syntheses of 7-fluoroprostaglandin F2α 1 and chemically stable 7-fluoro-17,20-dimethyl-2,4-methyleneprostacyclin 2 from commercially available methylenecyclopentanone are described. Construction of the key 7-hydroxyprostaglandin skeleton has been efficiently accomplished by the coupling of acetylenic acids with cyclopentanecarbaldehyde 4 under mild conditions.
  • Satoko Tanaka, Kazuyoshi Seguchi, Kuniaki Itoh, Akira Sera
    1996 Volume 69 Issue 12 Pages 3533-3542
    Published: 1996
    Released: June 29, 2006
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    The irradiation of oxime O-ethers 2, derived from N-substituted 3-acyl-1,2-dihydrocinnoline-1,2-dicarboximides in benzene, afforded rearranged products 3 possessing a [1,3,5]triazino[1,2-a]indole skeleton in good yields. Upon irradiation, 7-methoxy-substituted 1,2-dihydrocinnoline-1,2-dicarboximides 2 gave a novel dimer 5 together with the rearranged triazinoindole derivatives 3 in benzene, while in nucleophiles they gave the nucleophile-incorporated dihydrotriazinoindoles 6. However, the 7-nitro-substituted one was inert under the same conditions. The dimer and dihydrotriazinoindole derivatives were thought to be formed by a nucleophilic attack of the initial photoproduct 3 and nucleophiles to 2, respectively. From these results and the observation of a remarkable solvent-dependency of the fluorescence and UV spectra of 2, it was suggested that these photoreactions should occur through a nitrogen–nitrogen bond cleavage at polar excited states followed by skeletal rearrangements.
  • Tetsuo Iwagawa, Shun Nakamura, Hiroaki Okamura, Munehiro Nakatani
    Type: Accounts
    Subject area: AI
    1996 Volume 69 Issue 12 Pages 3543-3549
    Published: 1996
    Released: June 29, 2006
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    Ten new ichthyotoxic cembranoids: sartol A (1), 4-O-methylsartol A (2), sartones A (3), B (4), C (5), D (6), 4-O-methylsartone B (7), epoxysartone A (8), 6β-hydroxysarcotol acetate (9), and 4-O-methylsarcotol (10) have been isolated from the soft coral, Sarcophyton sp. The ichthyotoxicity tests were performed for 1, 37, and 10, including the reduction product and the acetate of 1.
  • Takeshi Murata, Toshihito Kumagai, Makoto Ishikawa, Kin-ichi Tadano, S ...
    1996 Volume 69 Issue 12 Pages 3551-3561
    Published: 1996
    Released: June 29, 2006
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    The thermal intramolecular Diels–Alder cycloaddition of a 2 : 1 mixture of ethyl (2E,8E and Z, 10E,13R)-13-(t-butyldimethylsilyl) oxy-2,10-dimethyl-2,8,10-pentadecatrienoate provided four diastereomeric cycloadducts. Deprotection of one of the cycloadducts provided PI-201, a novel platelet aggregation inhibitor, as its natural form. Three stereoisomers of PI-201 were prepared from the other cycloadducts. The intramolecular cycloadditions of some structurally similar trienes were also investigated.
  • Yoshiaki Kobuke, Hidekazu Miyaji
    Type: Accounts
    Subject area: AI
    1996 Volume 69 Issue 12 Pages 3563-3569
    Published: 1996
    Released: June 29, 2006
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    cis- and trans-bis(1-methyl-2-imidazolyl)tetraethyltetramethylporphyrin Mg complexes were prepared. 1H NMR, absorption, and fluorescence spectra suggest that Mg has a high tendency toward dimer formation through coordination from imidazolyl to metal in a similar way to Zn, and accepts further the sixth coordination, which never occurred in Zn complexes. Propagation of the organization from a dimer to a trimer for trans-Mg complex starts at such a low concentration level as 10−5 M (1 M = 1 mol dm−3) and a 2 × 10−3 M solution organized the system to a 2.34 mer on average.
  • Masato Kodaka, Anneli Hase
    1996 Volume 69 Issue 12 Pages 3571-3574
    Published: 1996
    Released: June 29, 2006
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    The free energy of binding between catalytic antibodies and substrates is correlated with the properties of the substrates, both in the transition state (TS) and the ground state (GS). The free energy of binding was calculated from the kinetic parameters and four properties of the substrates; the solvent accessible surface area (SAS), enthalpy of hydration (ΔH), polarizability (α), and dipole moment (μ) were calculated using AM1. As a whole, TS shows a higher correlation than does GS, which is compatible with the fundamental concept of a catalytic antibody. Among these four properties, SAS gives the highest correlation coefficient (0.7616) while μ has a small correlation. Antibody-TS complexes seem to be stabilized by van der Waals force rather than a hydrophobic interaction.
  • Osamu Harada, Suguru Sumita, Masami Sugita, Tohei Yamamoto
    1996 Volume 69 Issue 12 Pages 3575-3579
    Published: 1996
    Released: June 29, 2006
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    Characterization of pepsin-solubilized type I collagen was examined by a capillary electrophoresis using a capillary coated with α-dodecyl-ω-hydroxy poly(oxyethylene) to reduce protein adsorption and electroosmic flow. A good peak separation for each polypeptide was achieved at pH 5.6—6.5. The peaks were assigned to α1, α2, β11, β12, and γ by gel chromatography and reversed phase HPLC. It is found that each α chain signal split into several peaks, reflecting various residues of teropeptide.
  • Hiroshi Tomori, Hisayoshi Yoshihara, Katsuyuki Ogura
    Type: Accounts
    Subject area: AI
    1996 Volume 69 Issue 12 Pages 3581-3590
    Published: 1996
    Released: June 29, 2006
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    A facile optical resolution of recemic 1,2,3,4,10,14b-hexahydrodibenzo[c,f]pyrazino[1,2-a]azepine (1) was developed using 2,3-di-O-benzoyl-D-(−)-tartaric acid ((+)-DBT) as a resolving agent. The resolution efficiency depends remarkably on the (+)-DBT : 1 ratio. When (+)-DBT and recemic 1 were mixed in methanol–water (9 : 1 v/v) in a 1 : 4 stoichiometry, a crystalline salt consisting of (+)-DBT, (R)-1, methanol, and water in a 1 : 2 : 2 : 2 ratio crystallized preferentially in a fair yield. X-Ray crystallographic analysis showed its highly ordered supramolecular structure: (+)-DBT molecules self-assemble via hydrogen bonding with the aid of water and methanol to form a puckered layer, and stacking of (R)-1 molecules constructs a column which is sandwiched in between the puckered layers. The X-ray crystallographic data reported for the salts that consist of amines and DBT were reinvestigated to reveal that most of the host frameworks derived from DBT have a layer structure similar to the above puckered one.
  • Takayasu Kawasaki, Emiko Horimai, Hiromichi Ohta
    Type: Accounts
    Subject area: AI
    1996 Volume 69 Issue 12 Pages 3591-3594
    Published: 1996
    Released: June 29, 2006
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    The activation parameters of the enzymatic decarboxylation of malonic acid derivatives catalyzed by arylmalonate decarboxylase (AMDase) were obtained by means of kinetics. In order to understand the conformation of the substrate at the transition state, the activation entropy (ΔS) for indane-1,1-dicarboxylic acid, a representative molecule that is conformationally restricted, was compared with those of phenylmalonic acid and ortho-chlorophenylmalonic acid, of which the aromatic ring can freely rotate. The obtained value for the former molecule was about 10 cal mol−1 K−1 smaller than those of the latter compounds, clearly indicating that a conformationally restricted substrate, such as the indane derivative, is entropically advantageous for enzymatic decarboxylation. These kinetic studies evidently disclose that the conformation of the substrate at the transition state in the course of AMDase-catalyzed decarboxylation should be synperiplanar with regard to ortho- and α-substituents.
  • Hajime Irikawa, Kaori Ishikawa, Tomoko Akasaka
    Type: Accounts
    Subject area: AI
    1996 Volume 69 Issue 12 Pages 3595-3600
    Published: 1996
    Released: June 29, 2006
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    1,1′-Dimethyl and 1,1′-dichloro derivatives of the titled dimeric compound were prepared. A twisting of the central C2=C2′ double bond in the above-mentioned dimers was suggested based on the bathochromism observed in the absorption spectra. The 1,1′-dimethyl dimer was autoxidized at the enamine-type C1=C10b double bond to give 1,10b-dioxygenated products, while the 1,1′-dichloro dimer underwent a chlorine–hydrogen exchange to yield a 1,1′-dihydro compound upon heating in n-BuOH and 1,1,2,2-tetrachloroethane. These reactions might result from a strain around the twisted C2=C2′ double bond of the 1,1′-disubstituted dimers.
  • Tetsuo Onami, Masanori Ikeda, Scott S. Woodard
    Type: Accounts
    Subject area: AI
    1996 Volume 69 Issue 12 Pages 3601-3605
    Published: 1996
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    Most secondary alcohols and β,γ-unsaturated primary alcohols have been catalytically oxidized with N-chloro-4-chlorobenzenesulfonamide sodium salt to the corresponding carbonyl compounds by the addition of a 0.01—0.03 molar amount of dimethyl 2,2′-diselenodibenzoate in good-to-excellent yields, and a catalytic species, methyl 2-[N-(4-chlorophenylsulfonyl)aminoseleno]benzoate (8), was isolated from the reaction mixture. The catalytic oxidation cycle for this reaction is proposed; the decomposition of esters, which are produced by the reaction of alcohols with oxidized 8, was found to be the rate-determining step.
  • Shihoko Motoyama, Kiyoshi Takada, Teruo Yasunaga, Tsugumi Fujita, Yasu ...
    Type: Accounts
    Subject area: AI
    1996 Volume 69 Issue 12 Pages 3607-3612
    Published: 1996
    Released: June 29, 2006
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    The S-(3-nitro-2-pyridylthio) (Npys) group only reacts with a free mercapto group to form a disulfide bond. A series of morphiceptin analogs containing SNpys–cysteine were designed and synthesized for specific affinity-labeling of μ opioid receptors. Affinity-labeling of opioid receptors was monitored and evaluated by radioligand receptor binding assays using rat brain membranes and specific tritium-labeled ligands of enkephalin analogs. It was found that analogs with Cys(Npys) at position 4 or 5 bind covalently to μ receptors, but not to δ receptors, resulting in a discriminative and exclusive affinity labeling of μ opioid receptor subtype.
  • Kengo Kubota, Narihiko Fukamiya, Masayoshi Okano, Kiyoshi Tagahara, Ku ...
    Type: Accounts
    Subject area: AI
    1996 Volume 69 Issue 12 Pages 3613-3617
    Published: 1996
    Released: June 29, 2006
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    Two new quassinoids, ailantinol C and ailantinol D, were isolated from Ailanthus altissima, and their structures were elucidated from spectral evidence.
  • Ayumi Kamino, Hiroshi Koyano, Katsuhiko Ariga, Toyoki Kunitake
    1996 Volume 69 Issue 12 Pages 3619-3631
    Published: 1996
    Released: June 29, 2006
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    By using newly developed guanylating agents, octadecyl- and dioctadecylguanidinium amphiphiles were synthesized. The interaction between each guanidinium monolayer and polycarboxylates in the subphase was investigated on the basis of the πA isotherm, FT-IR spectroscopy, and XPS measurements. When linear dicarboxylates were used, the molecular areas of the monolayer increased, as the length of the methylene chain between the carboxylate groups increased. The expansion of the molecular area was greater for the octadecylguanidinium monolayers than for the dioctadecylguanidinium monolayers. The molecular packing was affected by the shape of polycarboxylate molecules in the case of phthalate, cis-1,2-cyclohexanedicarboxylate, and 1,1-cyclohexanediacetate. It is clear that, the molecular packing in the complexed monolayers is governed by the distance and relative orientation of the two carboxylate groups in a polycarboxylate. With all of the dicarboxylates, excluding oxalate, FT-IR and XPS measurements of the LB films indicated the formation of 1 : 1 guanidinium/carboxylate pairs with hydrogen bonding interactions. Oxalate produced an asymmetric complex where one guanidinium was bound to oxalate through hydrogen bonding, and the other guanidinium existed as a non-hydrogen bonded counter ion. These results are useful for the development of two-dimensional molecular patterns.
  • Masahiro Minabe, Yutaka Takabayashi, Yuji Setta, Hidenao Nakamura, Tak ...
    Type: Accounts
    Subject area: AI
    1996 Volume 69 Issue 12 Pages 3633-3638
    Published: 1996
    Released: June 29, 2006
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    The title azine was obtained by a reaction of the corresponding fluorenone hydrazone and p-substituted benzaldehyde. The hydrazone formed from the unsymmetrical fluorenone afforded configurational isomers; the E-isomer was thermodynamically more stable than the Z-isomer. The structure of the title azines, derived from symmetrical fluorenone, was assigned to be (s-trans/E) form. The azines from unsymmetrical fluorenone gave isomeric mixtures due to the 9-iminofluorene moiety. The electronic spectra of these azines show an intramolecular charge transfer; the red shift beyond 250 nm is observed in the case of 9-[p-(diethylamino)benzylidenehydrazono]-2,4,7-trinitrofluorene, compared to the mother azine. 9-[p-(Pentyloxy)benzylidenehydrazono]-2,7-dinitrofluorene and some of the homologs possess a liquid-crystalline property; the phase-transition temperature of the dinitro compound is K (172 °C) M1 (185) M2 (187) I between the crystalline and liquid phases.
  • Motoharu Kinugasa, Toshiro Harada, Takayuki Egusa, Katsuhiro Fujita, A ...
    Type: Accounts
    Subject area: AI
    1996 Volume 69 Issue 12 Pages 3639-3650
    Published: 1996
    Released: June 29, 2006
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    In the presence of a catalytic amount (0.1—0.2 molar amount) of a 2-phenyl-1,3,2-oxazaborolidin-5-one, prepared by the reaction of dichlorophenylborane and N-(trifluoromethylsulfonyl)-L-phenylalanine, and enol silyl ethers ((R2)2C=C(R3)OTMS; R3 = t-BuS, EtS, EtO, Ph) (1.1-1.5 molar amount), chiral cyclic acetals 6 derived from (R)-1,3-butanediol and aldehydes undergo an efficient ring-cleavage reaction with the inversion of the stereochemistry at the acetal carbon to give the anti isomer of the corresponding products with high stereoselectivity. The reaction is applicable to acetals derived from aromatic, aliphatic, and α,β-unsaturated aldehydes. Not only enol silyl ethers, but also methallyltrimethylsilane and allyltributyltin, can be employed as nucleophiles, leading to the selective formation of the anti isomer of the corresponding allylated ring-cleavage products. Removal of the chiral auxiliary from these ring-cleavage products by a two-step sequence ((i) PCC (ii) Bn2NH2(CF3CO2)) furnishes enantiomerically enriched β-hydroxy carbonyl compounds and homoallyl alcohols. A modest level of kinetic resolution is observed in the ring cleavage of a racemic acetal catalyzed by a phenylboron compound derived from N-mesyl-L-phenylalanine.
  • Hideo Tanaka, Shin-ichi Sumida, Yutaka Kameyama, Koichi Sorajo, Isao W ...
    Type: Accounts
    Subject area: AI
    1996 Volume 69 Issue 12 Pages 3651-3658
    Published: 1996
    Released: June 29, 2006
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    A straightforward synthesis of Δ3-cephems 2 bearing heteroatom substituents directly attached to C(3)-position was performed successfully by a sequential addition/cyclization reaction of allenecarboxylate 4 derived from eithen penicillin 1. Upon treatment of the allenecarboxylate 4 with morpholine, pyrrolidine, sodium azide, and 5-methyl-1,3,4-thiadiazole-2-thiol in DMF in the presence of calcium chloride, the addition/cyclization reaction proceeded smoothly to afford the corresponding 3-substituted Δ3-cephems 2ae. Reaction of the allenecarboxylate 4 with lithium chloride in NMP (N-methyl-2-pyrrolidone) in the presence of aluminum chloride afforded 3-chloro-Δ3-cephem 2f, while without aluminum chloride, 3-phenylsulfonyl-Δ3-cephem 2e was mainly obtained. The 3-sulfenyl-Δ3-cephems 12 were prepared by a similar addition/cyclization reaction of allenecarboxylates 10 with a catalytic amount of thiolates. The sulfenyl moieties attached at the sulfur atom of the C(4)-substituent of 10 were introduced at the C(3)-position of the cephem framework 2.
  • Hiroki Fukui, Kazunari Akiyoshi, Junzo Sunamoto
    1996 Volume 69 Issue 12 Pages 3659-3665
    Published: 1996
    Released: June 29, 2006
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    Colloidal stability of oil-in-water (o/w)-emulsion of α-linolenic acid (ALA) with or without trioctanoylglycerol (TriC8) was investigated in the presence of a hydrophobized polysaccharide, cholesteryl-bearing pullulan (CHP). The addition of ALA made the CHP/TriC8-emulsion more colloidally stable. A smaller and more colloidally stable o/w-emulsion was formed with an ALA/TriC8/CHP mixture. Electrophoretic light scattering measurements showed that the surface potential of the CHP/ALA/TriC8-emulsion was approximately zero. Fluorescence depolarization measurement using fluorescein isothiocyanate (FITC)-labeled CHP revealed that CHP adsorbs onto the surface of oil droplets and stabilizes the emulsion by a steric repulsion mechanism.
  • Yoshiaki Fukushima, Masaaki Tani
    1996 Volume 69 Issue 12 Pages 3667-3671
    Published: 1996
    Released: June 29, 2006
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    New organic/inorganic hybrid polymers, 2 : 1 type 3-(methacryloxy)propyl magnesium phyllosilicate and 2 : 1 type 3-(methacryloxy)propyl nickel phyllosilicate, were synthesized at room temperature by the copolymerization reaction of [3-(methacryloxy)propyl]trimethoxysilane to metal chloride hexahydrate. These polymers were studied by X-ray diffraction, Fourier-transformed infrared spectroscopy, and nuclear magnetic resonance measurements. The polymers have an inorganic part of phyllosilicate-like structure such as mica or smectite, and organic side chains linked to the inorganic framework through an –Si–C– covalent bond. The layered inorganic parts were considered consistent with well-ordered octahedral sheets and disordered –C–SiO3 tetrahedral sheets. The tendency of magnesium or nickel ions to form octahedral sheets played major part in the formation of the layered structure.
  • Takayuki Kondo, Kiyoshi Hasegawa, Ryutaro Uchida, Masanori Onishi, Aki ...
    Type: Accounts
    Subject area: AI
    1996 Volume 69 Issue 12 Pages 3673-3679
    Published: 1996
    Released: June 29, 2006
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    To estimate the effect of tree planting on atmospheric formaldehyde, the absorption of formaldehyde by various tree species was examined. The absorption rates varied from 8.6 (Japanese black pine) to 137 ng dm−2 h−1 ppb−1 (Lombardy poplar) at 1000 μmol of photons m−2 s−1, and the absorption rate increased in the following order: deciduous broad-leaved tree species > evergreen broad-leaved tree species > coniferous tree species. In experiments in which the light intensity was varied, a linear relationship between the formaldehyde absorption rate and the transpiration rate was observed for three tree species. From the results obtained from a simplified gas diffusive resistance model, we can conclude that formaldehyde is absorbed through the stomata, and is rapidly metabolized by three tree species. Even at a high concentration of about 2000 ppb, trees have the ability to absorb atmospheric formaldehyde for at least 8 h without any visible foliar injury. We conclude that trees in general could act as an important sink for atmospheric formaldehyde.
  • Nobuo Kimizuka, Tatsuo Wakiyama, Akihiro Yanagi, Seiji Shinkai, Toyoki ...
    1996 Volume 69 Issue 12 Pages 3681-3684
    Published: 1996
    Released: June 29, 2006
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    The calix[4]arene-mediated transport of alkali ions across black lipid membranes (BLM) of synthetic amphiphiles was examined by the charge pulse relaxation technique. Double-chain amphiphiles with cationic, anionic and nonionic head groups formed stable BLM’s, and the transport parameters for alkali ions were determined. The calix[4]arene derivative displayed an enhanced transport rate for Na+ ion across the synthetic BLM’s, while the relative adsorption/desorption rate (β) of alkali ions was significantly affected by the surface charge of the BLM’s.
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