Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
Volume 62 , Issue 3
Showing 1-50 articles out of 61 articles from the selected issue
  • Ken-ichiro Ota, Hiroyuki Sugimoto, Kazuo Fueki
    1989 Volume 62 Issue 3 Pages 653-656
    Published: 1989
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    The reaction of Fe with SO2 has been studied in the temperature range from 923 K to 1123 K and in the pressure range from 1.3 kPa to 101 kPa. The reaction obeyed the parabolic law except for the initial period, and the rate constant was equal to that in O2. In the scale, Fe3O4, FeO, and FeS were found as the reaction products. Among them, FeS was formed only in the initial period of the reaction and stayed at the scale/metal interface. The constant amount of sulfide in the scale became larger at higher temperatures or at lower SO2 pressures. The sulfide formation in the initial period of the reaction might cause the increase in the corrosion of Fe at low pressures of SO2 and cause the difference from the corrosion by O2.
  • Makio Iwahashi, Kimiyo Iiduka, Takashi Watanabe, Tsutomu Seimiya
    1989 Volume 62 Issue 3 Pages 657-661
    Published: 1989
    Released: June 27, 2006
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    The spreading pressure of a lipid monolayer in equilibrium with its crystal placed at the air/water interface is a thermodynamical property—i.e., the equilibrium spreading pressure (ESP). It is, however, quite likely that the apparently constant spreading pressure of a lipid with a relatively large desorption rate into the underlying subphase is not a thermodynamical property but merely a steady-state one. Mutual comparisons were, therefore, carried out for the rate constants of the six possible processes associated with the spreading pressure of tetradecanoic acid, whose monolayer has a relatively large desorption rate into the underlying subphase; it was found that monolayer formation from its crystal was predominant and that the desorption from the monolayer little affected the spreading pressure, even at high temperatures. Consequently, the apparently constant spreading pressure for the tetradecanoic acid can be regarded as the ESP even at high temperatures, in which the dissolution of the monolayer into the subphase occurs very rapidly.
  • Shinsaku Fujita
    1989 Volume 62 Issue 3 Pages 662-667
    Published: 1989
    Released: June 27, 2006
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    Five-center organic reactions are formulated in the form of pentagonal reaction-center graphs (RCC’s) that are subgraphs of imaginary transition structures. This formulation is based on the concept of a charge space that affords rational representations of coordinate bonds. Pólya’s theorem is applied to the enumeration of these RCG’s, in which the obligatory minimum valencies of vertices restrict the mode of substitution.
  • Katsumi Tanigaki, Noriyuki Taguchi, Mikio Yagi, Jiro Higuchi
    1989 Volume 62 Issue 3 Pages 668-673
    Published: 1989
    Released: June 27, 2006
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    For the phosphorescent triplet (T1) states of symmetrically-substituted dimethylbiphenyls, the relationship between the twisting angle of the two aromatic rings and the zero-field splitting parameters is discussed in terms of the ESR spectra. Two sets of ESR spectra observed for 2,2′- and 3,3′-dimethylbiphenyls (2DMBP and 3DMBP) are precisely assigned to the corresponding s-cis or s-trans conformer. The results clarify the inadequate assignment of the spectra of these molecular species in the previous literature. The lifetime obtained for the s-cis conformer is different from that of the s-trans one for both 2DMBP and 3DMBP. Examining the T1–T1 energy transfer from one conformer to the other, the relative locations for the T1 states of s-cis and s-trans conformers are obtained, even if phosphorescence measurements do not provide each isolated spectrum: ET (s-cis-3DMBP)<ET(s-trans-3DMBP) and ET(s-cis-2DMBP)>ET(s-trans-2DMBF).
  • Tokuyuki Kuroda, Koji Hisamura, Ikuo Matsukuma, Hiroshi Nishikawa, Nob ...
    1989 Volume 62 Issue 3 Pages 674-681
    Published: 1989
    Released: June 27, 2006
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    A new concept, “Radiation-Induced Drug (RID)”, was proposed as a novel type of drugs for cancer therapy. To test the usefulness of this concept, 5-fluorouracil (5-FU) derivatives having various types of substituents at the 1-position were prepared and the γ-radiolyses of their aqueous solutions were studied. The compounds having sulfonyl and thioureido groups as the substituents produced efficiently 5-FU with high G values upon γ-irradiation. The medium effects on the radiolyses revealed that the above two substituents were removed mainly with HO· and hydrated electrons eeq.
  • Yukihiro Yokoyama, Yutaka Takakura, Takeshi Sawasaki, Kensuke Takahash ...
    1989 Volume 62 Issue 3 Pages 682-686
    Published: 1989
    Released: June 27, 2006
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    The dicarbanions (1 and 2) produced from 1,1,4,4-tetraphenyl- and 1,4-diphenylbutadienes (1a and 2a) were investigated by means of the 1H and 13C NMR techniques. Large upfield shifts of the proton and carbon signals caused by the conversion of the hydrocarbons into the dianions were observed. Such shifts were used for evaluating the excess charge distributions in the dianions. From the coupling constants obtained it is concluded that the configuration of the central bond of the anion is the trans one for 1 but the cis one for 2. Thermodynamical parameters were obtained for the restricted rotation of the phenyl group of the lithium salt of 2.
  • Kyuya Yakushi, Hideo Yamakado, Michiko Yoshitake, Nobuhiro Kosugi, Har ...
    1989 Volume 62 Issue 3 Pages 687-696
    Published: 1989
    Released: June 27, 2006
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    The single crystals of NiPc(SbF6)0.5 and NiPc(AsF6)0.5 were prepared by means of an electrochemical method. The electrical, magnetic, optical, and structural properties of these crystals were examined. These crystals are isostructural to each other, and exhibit a metallic behavior at least above 200 K. The g-values of the ESR signals remarkably depend upon temperature. By the aid of the low temperature experiments of XANES and reflectance spectrum, the temperature dependence is explained by the model based on the interaction between the small amount of local spins on the Ni atoms and the conduction electrons on the ligand chain. In addition, a sample dependence was found on the ESR properties of the crystals of NiPc(AsF6)0.5. This is attributed to the sample dependence of the concentration of the local spins on Ni atoms. From these considerations, we concluded that the ligand part is mainly oxidized in these partially oxidized salts, in other words the conduction electrons are located on the ligand chain. The bandwidth of the conduction band was estimated to be about 1 eV.
  • Yoh Sano
    1989 Volume 62 Issue 3 Pages 697-700
    Published: 1989
    Released: June 27, 2006
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    Using the light scattering theory of Rayleigh–Gans, theoretical expressions were derived for the state of polarization of light scattered by anisotropic spheroids in the case of linearly polarized incident light whose electric vector is inclined by ψ to the scattering plane. The azimuth of the ellipse of the light scattered is a function of the two scattering angles, θ and ψ, only and the scattered light is linearly polarized for linearly polarized incident light. The degree of polarization of the scattered light, which is defined as the ratio of the polarized component to the intensity of the scattered light, depends on the intrinsic anisotropy, pm; the relative refractive index of the spheroid to the solvent, m, and θ, together with the ψ angle. The degree of polarization varies from 1.0 to 0, depending strongly on pm, p and m. It has been suggested that the determination of the degree of polarization as a function of ψ and θ provides good information about the optically intrinsic anisotropy of the spheroid.
  • Tai-ichi Shibuya, Tadashi Funada, Susumu Narita
    1989 Volume 62 Issue 3 Pages 701-708
    Published: 1989
    Released: June 27, 2006
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    The previously proposed idea of parametrizing the equations-of-motion method [Int. J. Quantum Chem., 18, 205 (1980)] has been worked out for the π→π* transitions of linear polyenes. The excitation operator consists of not only 1p-1h creation and annihilation operators but also 2p-2h creation and annihilation operators. [Bull. Chem. Soc. Jpn., 61, 1103 (1988)]. The proposed scheme accounts for the effect of σ→σ* mixings in contrast with the traditional pi-electron theories. In the present work, the two-center Coulomb integrals are evaluated by 1/R, and all the one-center integrals on the C atom are assumed to be the same. Values of the three parameters (a, b, ζ) introduced in the scheme are so determined that the computed excitation energies of ethylene and s-trans-butadiene fit the observed values. The scheme has been applied to a series of all-s-trans linear polyenes through dodecahexaene. Some notable results are: (1) The σ→σ* mixings play a significant role in lowering the excitation energies of the allowed transition to 11Bu; (2) the 21Ag state is of Ag type and almost free from this effect; (3) double excitations (2p-2h states) are dominant in the 21Ag state but practically negligible in the 11Bu state.
  • Akira Endo, Yoshimasa Hoshino, Keigo Hirakata, Yasushi Takeuchi, Kunio ...
    1989 Volume 62 Issue 3 Pages 709-716
    Published: 1989
    Released: June 27, 2006
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    The one-electron oxidation and reduction processes at platinum electrodes of a series of β-substituted and γ-substituted tris(β-diketonato)ruthenium(III) complexes are studied in acetonitrile, N,N-dimethylformamide, and nitromethane solutions, each containing 0.1 mol dm−3 (C2H5)4NClO4 at 25 °C. Syntheses of three new γ-substituted derivatives are described. Attempts to isolate the immediate product of the one-electron oxidation of [Ru(acac)3] in acetonitrile failed; bis(acetonitrile)bis(acetylacetonato)ruthenium(III) was obtained instead. Diffusion coefficients of the complexes in the acetonitrile medium are presented. The reversible half-wave potentials for the oxidation and the reduction in the acetonitrile medium depended linearly on the sum of the Hammett constants of the substituents (σp for the β-substituents and σm for the γ-substituents). Analysis of the dependence of the half-wave potentials on several kinds of substituent parameters suggests that the inductive effect is operative at both the β-positions and the γ-position, while the resonance effect is operative only at the β-positions.
  • Toshio Okuhara, Shin Tatematsu, Kwan Young Lee, Makoto Misono
    1989 Volume 62 Issue 3 Pages 717-723
    Published: 1989
    Released: June 27, 2006
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    The absorption of organic molecules into the bulk of H3PW12O40 and its salts was studied. Polar (or basic) molecules, such as alcohols and amines, were readily absorbed into H3PW12O40, but nonpolar hydrocarbons were not absorbed. The absorption depended not only on the polarity but also on the molecular size. The diffusion coefficients of the absorption of C1–C4 alcohols were of similar magnitudes, and were much smaller than that of the intracrystalline diffusion of methanol in ZSM-5. The amounts of absorbed molecules in H3PW12O40 tended to be in discrete values: that is, integral multiples of the number of protons (3, 6, etc.). This fact indicates that these polar molecules are protonated and form stable secondary structures throughout the bulk. It was confirmed in the case of methanol or ethanol that the transition between the states of 6 and 9 molecules/anion took place through the pressure changes. The absorptivity was greatly suppressed by the substitution of Cs+ for more than two H+, while the Na salts showed an absorptivity similar to that of H3PW12O40.
  • Yoshihisa Yamamoto, Kayoko Yoshii, Eiko Toyota, Kazuko Konno
    1989 Volume 62 Issue 3 Pages 724-729
    Published: 1989
    Released: June 27, 2006
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    cis1 and β2-Thiosalicylato(quadridentate amine)cobalt(III) complexes, cis1, β2-[Co(thiosal)L]X·nH2O (L: trien (2,2,2-tet), 3,2,3-tet; X: Cl, NO3), have been prepared from a reaction mixture of [CoCl2L]Cl·nH2O (L: trien, 3,2,3-tet), Ag2O, thiosalicylic acid (o-mercaptobenzoic acid), and 28% aqueous ammonia. Two geometrical isomers (cis-β1 and β2) of their complexes were separated by Dowex 50W-X2 column chromatography. The isomerization between the cis-β1 and β2-isomers is reversible in water at 40 °C. The IR spectra of these complexes showed four or five absorption bands in the 990–1100 cm−1 region and four absorption bands in the 3000–3300 cm−1 region. This indicates that these complexes assume the cis-β1-form. Their cis-β1 and β2 configurations have been established by their absorption and NMR spectra. The cis-β1 and β2-thiosalicylato(trien)cobalt(III) complexes have been tentatively assigned to the RR,SS diastereoisomer by their 1H NMR spectra. The color of solid state materials, solubilities in alcohols, isomerization at 40 °C, reaction in 60% nitric acid, absorption spectra, and chemical shift of Co–S–C carbon of the coordinated thiosalicylato ligand for the title complexes are different from those of the corresponding cis1 and β2-salicylato(quadridentate amine)cobalt(III) complexes, cis1, β1-[Co(sal)L]Cl·nH2O (L: trien, 2,3,2-tet, 3,2,3-tet, 3,3,3-tet), reported previously.
  • Nobuyoshi Shinohara, Makoto Inoue
    1989 Volume 62 Issue 3 Pages 730-733
    Published: 1989
    Released: June 27, 2006
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    In the flash photolysis of Sn(II) in a deaerated hydrochloric acid solution, Sn(III) was produced. Sn(III) has an absorption maximum at 280 nm in a l mol dm−3 hydrochloric acid solution. In the flash photolysis of a deaerated Sn(IV) solution, intermediates of Sn(III) and Cl2 were produced. Transient absorption spectra of intermediates generated by the flashed Sn(IV) solutions were measured under various concentrations of dissolved oxygen. Since Sn(III) reacts with oxygen very rapidly, only Cl2 was confirmed in the oxygen-saturated Sn(IV) solution. In the flash photolysis of Sn(IV) solutions containing Sn(II), the yield of Sn(III) increased with an increase of the added Sn(II), due to the generation of Sn(III) by the reaction of Cl2 with Sn(II). It was found that only Sn(III) was produced in the irradiation of 5.0×10−4 mol dm−3 Sn(IV) solution containing Sn(II) at concentrations of more than ca. 7×10−5 mol dm−3. The reaction rate constant for the reaction of Sn(II) with Cl2 was estimated to be 8.9×108 mol−1 dm3 s−1. The mechanisms for the photochemical generation of Sn(III) are discussed.
  • Nobuyoshi Shinohara, Yayoi Nakamura
    1989 Volume 62 Issue 3 Pages 734-737
    Published: 1989
    Released: June 27, 2006
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    The photochemical decomposition of oxoperoxovanadium(V), VO(O2)+, was studied in perchloric acid media. It was found that the irradiation of VO(O2)+ solutions with 313, 365, and 436 nm exciting light resulted in the photoreduction of the complex, and gave VO2+, with an evolution of oxygen. The overall reaction is: 4VO(O2)++4H+–→4VO2++3O2+2H2O. The photochemical reaction mechanism is also discussed.
  • Makoto Johda, Masatatsu Suzuki, Akira Uehara
    1989 Volume 62 Issue 3 Pages 738-744
    Published: 1989
    Released: June 27, 2006
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    Preparation of the μ-cyano dinuclear complexes MI[F(en or tn)2Cr(NC)Cr(CN)5nH2O from the double complexes MI[CrF(H2O)(en or tn)2][Cr(CN)6nH2O was carried out both in the solid state and in solution, where MI is Li+, Na+, K+, or Rb+ ion; en and tn stand for 1,2-ethanediamine and 1,3-propanediamine, respectively. The desired μ-cyano dinuclear complexes were successfully obtained in solution, but the mixture of di- and trinuclear complexes was formed along with unknown polymeric species in the solid state. The electronic spectra of the dinuclear complexes exhibited a small but clear band due to spin-forbidden transition (4A2g2Eg). Magnetic moments of the dinuclear complexes were 3.4–3.5 μβ at ambient temperatures and 2.2–2.4 μβ at 80 K, which are substantially smaller than the spin-only value (3.87 B.M.). The J values for the dinuclear complexes were estimated to be −19–−20 cm−1, indicating that an antiferromagnetic superexchange interaction is exerted between two chromium(IH) ions through μ-CN group, but the magnitude of the interaction is smaller than that of the μ-oxo complexes (J=−450 cm−1) and comparable to that of the μ-hydroxo complexes (J=−23 cm−1) reported previously.
  • Yutaka Fukuda, Chiori Fujita, Hiroshi Miyamae, Hiroko Nakagawa, Kozo S ...
    1989 Volume 62 Issue 3 Pages 745-752
    Published: 1989
    Released: June 27, 2006
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    Several new mixed nickel(II) nitrate complexes with 1,2-dipiperidinoethane (dipe) and β-diketonate ions (dike), [Ni(NO3)(dike)(dipe)], have been obtained and characterized. The crystal structure of one of them, [Ni(NO3)(acac)(dipe)], was determined by X-ray crystallography. The crystal is monoclinic with the space group Cc, Z=4, a=9.0517(4), b=21.932(1), c=9.8814(6) Å, β=88.151°. Block-diagonal least-squares refinements have led to a final R value of 0.036 for 2471 reflections. It was confirmed that the nitrate ion in the octahedral complex acts as a bidentate ligand and that the conformation of the piperidine ring in dipe is a chair form. The spectral behaviors of these complexes in various organic solvents are discussed in comparison with those of similar complexes with other N,N′-alkylated ethylenediamine ligands (diam). It was concluded that, in a solvent with low polarity, the complexes are dissolved unchanged; in a more polar solvent, however, dissociation of NO3 takes place, producing solvated or unsolvated cationic species ([Ni(dike)(diam)(Solvent)2]+ (Oh) or [Ni(dike)(diam)]+ (Square Planar)) according to the donor and acceptor properties of the solvent.
  • Hiroshi Kawaguchi, Masato Shimizu, Tomoharu Ama, Takaji Yasui
    1989 Volume 62 Issue 3 Pages 753-759
    Published: 1989
    Released: June 27, 2006
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    The isomerization and racemization reactions of the [Co(ida)(dien)]+ and [Co(ida)(mdien)]+ systems were studied in an aqueous solution. The main isomerization path of the [Co(ida)(dien)]+ system was u-fac\ ightleftharpoonsmer\ ightleftharpoonss-fac and the rate law for each of the processes could be described as R=k[complex][OH]. In the [Co(ida)(mdien)]+ system, there was an additional isomerization path of u-facs-fac. The equilibrium mole ratio of three isomers was u-fac:mer:s-fac=25:19:56% for [Co(ida)(dien)]+ and u-fac:mer:s-fac=3:3:94% for [Co(ida)(mdien)]+. In the isomerization of (+)564CD-u-fac-[Co(mida)(mdien)]+, (+)582CD-mer isomer was stereoselectively produced. The racemization mechanisms of mer-[Co(ida)(dien)]+ and mer-[Co(mida)(dien)]+ are also discussed.
  • Kiyohiko Nakajima, Masaaki Kojima, Koshiro Toriumi, Kazuo Saito, Junno ...
    1989 Volume 62 Issue 3 Pages 760-767
    Published: 1989
    Released: June 27, 2006
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    A reddish brown oxovanadium(V) complex, [VVO(sal-L-ala)(OCH3)(CH3OH)] (2a, sal-L-ala=N-salicylidene-L-alaninate) was formed by dissolving [VIVO(sal-L-ala)(H2O)] (1a) in methanol. Treatment of 2a with wet dichloromethane yielded deep blue crystals of {[VVO(sal-L-ala)]2O}2·2CH2Cl2 (3a). The structures of 2a and 3a have been determined by X-ray analyses. Crystal data are: [VO(sal-L-ala)(OCH3)(CH3OH)] (2a), monoclinic, C2, a=19.621(6), b=6.734(1), c=12.059(4) Å, β=117.72(2)° and Z=4. {[VO(sal-L-ala)]2O}2·2CH2Cl2 (3a), orthorhombic, P212121, a=19.938(4), b=23.854(5), c=11.526(2) Å, and Z=4. In 2a, the tridentate sal-L-ala ligand and a methoxide ion occupy the basal positions, and form distorted octahedral geometry around the vanadium(V) ion together with one methanol molecule (V–O distance: 2.384(4) Å) and the oxide ion of oxovanadium(V). The tetranuclear complex (3a) consists of two μ-oxo dinuclear vanadium(V) complexes, and each vanadium(V) ion has a distorted octahedral coordination. The Schiff base coordinates equatorially to each vanadium(V) ion, of which one axial site is occupied by O2− and the other is weakly linked to the carboxylate O atom of a nearby Schiff base (V–O distance: 2.34–2.56 Å). Octahedral coordination on each vanadium(V) is achieved by sharing an equatorial O2− ligand. The brown complexes, [VO(sal-L-aa)(OCH3)(CH3OH)] (2, sal-L-aa=N-salicylidene L-amino carboxylate) catalyze the oxidation of methyl phenyl sulfide with t-butyl hydroperoxide in dichloromethane at 4 °C to give (R)-methyl phenyl sulfoxide with optical yields (e.e.) of 8–14%.
  • Hideyuki Tagaya, Hiroaki Saito, Susumu Suda, Koji Chiba
    1989 Volume 62 Issue 3 Pages 768-772
    Published: 1989
    Released: June 27, 2006
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    A higher formation of the methylviologen radical cation was observed at higher pH and when the counter ion of an oxalate ion was large in the continuous photolysis of deaerated solutions of methylviologen (MV2+)–oxalate ion (C2O42−). A dissociation of oxalic acid to the ion depended upon the pH at pH<7 and the dissociation constant of a MV2+–C2O42− complex depended on the pH at pH>10. The calculated absorbance of the MV2+–C2O42− complex at 350 nm, by using the dissociation constants of oxalic acid and the complex, agreed well with the observed absorbance. It was considered that the pH depedence of the MV\underset.+ formation resulted from the pH dependence of the concentration of the MV2+–C2O42− complex. The effect of a counter ion on the photoinduced electron transfer was explained in terms of the difference in the stability of the complex ion, in which smaller ions (Li+, Na+) tended to form more stable complexes than larger ions (NH4+, K+).
  • Mitsuaki Narita, Shizuko Isokawa, Shinya Honda, Hiroshi Umeyama, Hidea ...
    1989 Volume 62 Issue 3 Pages 773-779
    Published: 1989
    Released: June 27, 2006
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    The conformational behavior of cross-linked polystyrene resin-bound peptides swollen in CH2Cl2 was analyzed using IR absorption spectroscopy. All of the resin-bound peptides easily aggregated with each other through intermolecular hydrogen bonding to form a β-sheet structure. The disruption of the β-sheet structure was further investigated by a solvent titration method in order to clarify the individuality of amino acid residues. At a pentapeptide level, the β-sheet structure was easily disrupted by the addition of a small amount of HFIP. On the other hand, at a larger peptide level, the disrupted behavior of the β-sheet structure was different from each other according to the amino acid composition. Based on the view that the secondary structure of globular proteins reflects the individuality of the 20 kinds of amino acid residues in proteins, we attempted to evaluate how easily the β-sheet structure of peptides is disrupted by HFIP using the average conformation values: ⟨Pα⟩, ⟨Pβ⟩, and ⟨Pc⟩. As a result, the β-sheet structure-disruption of peptides having a low potential for a β-sheet→helix transformation as well as for the randomness was difficult by adding increasing amounts of HFIP. On the other hand, that of the peptides having a ⟨Pc⟩ value larger than 0.85 and/or a high potential for the β-sheet→helix transformation proceeded smoothly upon adding increasing amounts of HFIP.
  • Mitsuaki Narita, Hiroshi Umeyama, Shizuko Isokawa, Shinya Honda, Chie ...
    1989 Volume 62 Issue 3 Pages 780-785
    Published: 1989
    Released: June 27, 2006
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    Cross-linked polystyrene resin-bound peptides were useful for the investigation of the β-sheet structure-disrupting potential of mixed solvents although their β-sheet structure-disrupted behavior by mixed solvents was different from that of peptides free from a macromolecular protecting group due to the concentrating efficacy of a cross-linked resin. In mixed solvents, the electron-acceptor and -donor numbers (AN and DN) of organic solvents were one of the most important factors to estimate their β-sheet structure-disrupting potential. In a mixture of electron-acceptor solvents themselves or -donor solvents, the electron donor-acceptor interaction between solvents did not occur and electron-accepting or -donating property of each solvent was kept to disrupt the β-sheet aggregation in mixed solvents. On the other hand, in a mixture of electron-acceptor solvent and -donor solvent, the electron donor-acceptor interaction between solvents occurred predominantly to decrease the β-sheet structure-disrupting potential of mixed solvents. The present results clarify the criteria of the search for effective solvents in peptide and protein synthesis.
  • Koichi Fujishiro, Shuichi Mitamura
    1989 Volume 62 Issue 3 Pages 786-790
    Published: 1989
    Released: June 27, 2006
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    The Henkel reaction of dipotassium 1,8-naphthalenedicarboxylate in naphthalene as a dispersion medium gave dipotassium 2,6-naphthalenedicarboxylate (1) in a higher yield and with a better reproducibility than the reaction without a dispersion medium. Catalysts, particularly zinc catalysts, were examined in detail. The anion moiety of zinc catalysts affected the reaction, and the halide anion was effective for the selective formation of 1. The addition of potassium halide to the zinc catalysts also increased the yield of 1. The catalytic activity of the halide anion increased in the order; Cl<Br<I. The activity of the zinc catalysts was also compared with that of cadmium catalysts.
  • Anders Carlsson, Toshinori Sato, Junzo Sunamoto
    1989 Volume 62 Issue 3 Pages 791-796
    Published: 1989
    Released: June 27, 2006
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    A methodology to improve lipid microspheres (LM) as a carrier for lipophilic drugs and their physicochemical properties are described. The LM were prepared from glycerides, glycerol, and phospholipids. The method involves coating of the surface of the LM with a naturally occurring or chemically modified polysaccharide. Special emphasis will be made on cholesterol-bearing pullulan and amylopectin. This is the same approach as that adopted for the stabilization of liposomes. Turbidity measurement revealed that the coating effectively depressed the Ca2+-induced aggregation of the LM. From fluorescence polarization measurements, it was concluded that the fluidity of the LM surface decreased with the polysaccharide coating. Furthermore, the coating effect was investigated by zeta-potential measurements. The coating reduced the negative zeta-potential of the LM to an apparently neutral value.
  • Akira Hosaka, Shuji Ichikawa, Hiroko Shindo, Tadashi Sato
    1989 Volume 62 Issue 3 Pages 797-799
    Published: 1989
    Released: June 27, 2006
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    (Synthesis of 2S,3R,4R)-2-hydroxymethyl-3,4-pyrrolidinediol and 4-acetamido-1,2,3-tri-O-acetyl-4-deoxy-L-xylopyranose were attained in four steps from D-mannose, using iron(III)-catalyzed photoreaction as a key reaction.
  • Nobuya Kitaguchi
    1989 Volume 62 Issue 3 Pages 800-807
    Published: 1989
    Released: June 27, 2006
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    Electronic spectra of substituted 9,10-dihydro-9,10-o-benzenoanthracene-1,4-diones (triptycenequinones) in various solvents and that of benzo- and dibenzotriptycenequinones were investigated in this paper. Intramolecular charge-transfer (CT) bands ware observed in triptycenequinone system as a result of intramolecular interaction between benzene ring and benzoquinone moiety. Substituents on the benzene rings strongly affected the CT bands. Electron-donating groups gave absorption maxima at long wavelength. Naphthalene ring gave similar but stronger CT bands than benzene ring. Hammett σ+ value of substituents gave good linear relationship with the energy of the CT bands. Calculations of reduced charge matrix of triptycenequinones by extended Hückel theory showed that the charge of aromatic ring(s) were transferred to benzoquinone moiety accompanying HOMO–LUMO excitation. Especially, absorption maxima of the methyl-substituted triptycenequinones gave good correlation with the amounts of charge transferred from benzene ring to benzoquinone moiety. These analysis confirmed clearly CT character of the absorption maxima of triptycenequinones. However, solvent effect of these CT bands maxima is not so clear as the substituent effect.
  • Kazunori Ueno, Shuji Kanemasa, Otohiko Tsuge
    1989 Volume 62 Issue 3 Pages 808-815
    Published: 1989
    Released: June 27, 2006
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    Cycloadditions of azomethine ylides generated from α-benzylideneamino nitriles bearing a hydroxyl or its O-protected moiety with α,β-unsaturated esters such as dimethyl maleate, fumarate, methyl acrylate, crotonate, methacrylate, and cinnamate lead stereoselectively to 3,3a-trans-3a,9b-cis-3a,9b-dihydro[1]benzopyrano[4,3-b]pyrrole-4(3H)-ones after subsequent lactonization.
  • Kazuhiro Maruyama, Hiroshi Imahori
    1989 Volume 62 Issue 3 Pages 816-825
    Published: 1989
    Released: June 27, 2006
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    Photochemical reactions of quinones with allylstannanes provided four types of products: adducts of allyl group to the carbonyl oxygens of quinones, adducts of allyl group to the olefinic carbons, adducts of allyl group to the carbonyl carbons, and hydroquinones. An electron-transfer mechanism was confirmed by 1H-CIDNP (Chemically Induced Dynamic Nuclear Polarization) method. This study suggests that a) photoinduced electron transfer from allylstannanes to quinones produces the corresponding quinone anion radicals and tin cation radicals, b) the tin cation radicals cleave to give allyl radicals as well as tin cation, and c) the allyl radicals attack the quinone anion radicals resulting in the formation of final products, allylated quinones.
  • Masao Tsukayama, Yasuhiko Kawamura, Hiroto Tamaki, Tomoya Kubo, Tokuna ...
    1989 Volume 62 Issue 3 Pages 826-832
    Published: 1989
    Released: June 27, 2006
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    Elongatin (4′,5-dihydroxy-2′,5′-dimethoxy-2″,2″-dimethylpyrano[5″,6″-g]isoflavone) was synthesized by an oxidative rearrangement of the corresponding pyronochalcone [6-(1-oxo-3-phenyl-2-propenyl)-4-chromanone] with thallium(III) nitrate and a regioselective reduction of 7-(4-benzoyloxy-2,5-dimethoxyphenyl)-2,3-dihydro-2,2-dimethyl-5-tosyloxy-4H,6H-benzo[1,2-b:5,4-b′]dipyran-4,6-dione with sodium boronydride–palladium chloride, followed by dehydration of the resultant alcohol and hydrolysis. Its angular isomer (4′,5-dihydroxy-2′,5′-dimethoxy-2″,2″-dimethylpyrano[6″,5″-h]isoflavone) was also synthesized from the corresponding pyronochalcone in a similar manner.
  • Hidenori Chikashita, Eiji Kittaka, Yasunori Kimura, Kazuyoshi Itoh
    1989 Volume 62 Issue 3 Pages 833-837
    Published: 1989
    Released: June 27, 2006
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    A short and stereoselective asymmetric synthesis of (2S,4R)-7-octene-2,4-diol (a key intermediate in the Bartlett synthesis of nonactic acid) and two stereoisomers of a biologically active substance isolated from Norway spruce infested by ambrosia beetle, endo-(1S,3S,5R)- and exo-(1R,3S,5S)-1,3-dimethyl-2,9-dioxabicyclo-[3.3.1]nonane, was effectively accomplished in three and four reaction steps, respectively, by starting with easily obtainable (S)-1-(1,3-dithian-2-yl)-2-propanol by baker’s yeast asymmetric reduction. The main strategy was based on a facile construction of optically active β-hydroxy ketones via alkylation of the dianion of (S)-1-(1,3-dithian-2-yl)-2-propanol with alkyl halides, followed by their stereoselective reductions.
  • Tyo Sone, Kazuaki Sato, Yoshihiro Ohba
    1989 Volume 62 Issue 3 Pages 838-844
    Published: 1989
    Released: June 27, 2006
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    Crown ethers containing 3,4-thiophenediyl and 3,4-thiophenediylbis(methylene) subunits as a ring constituent were prepared starting from 2,5-bis(ethoxycarbonyl)-3,4-thiophenediol and 2,5-dichloro-3,4-bis(chloromethyl)thiophene, respectively. A Raney nickel desulfurization of the thiophene-containing crown ethers afforded crown ethers having two adjacent side chains, such as a methyl or ethoxycarbonylmethyl group. The extraction ability of these crown ethers towards alkali metal cations was also examined by the solvent extraction method.
  • Yuh-ichiro Ichikawa, Hideki Kubota, Ken’ichi Fujita, Tatsuo Okau ...
    1989 Volume 62 Issue 3 Pages 845-852
    Published: 1989
    Released: June 27, 2006
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    β-C-2-Deoxyribofuranosides and β-S-2-deoxyribofuranosides are prepared stereoselectively from 1-O-acetyl-5-O-benzyl-3-O-[2-(methylsulfinyl)ethyl]-2-deoxy-D-erythro-pentofuranose or the corresponding 3-O-(2-pyridyl-methyl)pentofuranose N-oxide by the reaction with silyl enol ethers or trimethlsilyl sulfides in the presence of a Lewis acid.
  • Ikuya Shibata, Kenji Nakamura, Akio Baba, Haruo Matsuda
    1989 Volume 62 Issue 3 Pages 853-859
    Published: 1989
    Released: June 27, 2006
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    Novel types of compounds, N-tributylstannyl-2-oxazolidinone (4a) and tetrahydro-2H-1,3-oxazin-2-one (4b), are formed from the adduct of (n-Bu3Sn)2O (1) with ω-haloalkyl isocyanate (2), and the subsequent coupling reaction with alkyl halides gives a variety of N-substituted 2-oxazolidinones and tetrahydro-2-oxazinones in a one-pot procedure. Both the cyclization and the coupling reaction proceed quantitatively in the presence of HMPA which enhances the reactivity of the Sn–heteroatom bond by coordination.
  • Eiji Wada, Shuji Kanemasa, Otohiko Tsuge
    1989 Volume 62 Issue 3 Pages 860-868
    Published: 1989
    Released: June 27, 2006
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    A new method of synthesizing phosphinyl-substituted enones, 2-oxo-3-alkenylphosphonates, is developed via the dianion of diethyl 2-oxopropylphosphonate. The enones serve as hetero dienes in thermal reactions with vinly ethers producing 2-alkoxy-6-(phosphinylmethyl)-3,4-dihydro-2H-pyrans. Acid-catalyzed cleavage of these cycloadducts is followed spontaneously by internal condensation furnishing 2-phosphinyl-2-cyclohexen-1-one derivatives.
  • Shuji Kanemasa, Manabu Yoshioka, Otohiko Tsuge
    1989 Volume 62 Issue 3 Pages 869-874
    Published: 1989
    Released: June 27, 2006
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    The lithiated intermediate derived from methyl 2-(benzylideneamino)propanoate and lithium bromide/triethylamine undergoes cycloaddition and Michael addition with methyl acrylate. 1,3-Dipole character of the intermediate is suggested on the basis of the product ratios obtained under a variety of conditions. The reaction mechanism via a four-centered transition state is proposed.
  • Kaoru Nakamura, Yasushi Kawai, Shinzaburo Oka, Atsuyoshi Ohno
    1989 Volume 62 Issue 3 Pages 875-879
    Published: 1989
    Released: June 27, 2006
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    Stereochemistry of the reduction of β-keto esters with bakers’ yeast is controlled by the addition of a certain α,β-unsaturated carbonyl compound (or its reduced form). Glucose also exerts the same effect. The additives tend to shift the stereochemistry of the reduction toward the production of D-hydroxy ester. Namely, methyl 3-oxopentanoate and ethyl 3-oxo-6-heptenoate were reduced to the corresponding D-hydroxy esters with excellent stereoselectivities and chemical yields. The enones are supposed to inhibit the enzymes that produce the L-hydroxy ester, whereas glucose plays a role to activate the enzymes that produce the D-hydroxy ester.
  • Hajime Irikawa, Yasuhiro Toyoda, Hiroaki Kumagai, Yasuaki Okumura
    1989 Volume 62 Issue 3 Pages 880-887
    Published: 1989
    Released: June 27, 2006
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    Four 2,3,5,6,11,11b-hexahydro-3-oxo-1H-indolizino[8,7-b]indole-5-carboxylic acids, plausible precursors of trichotomine, were isolated as the methyl esters from Clerodendron trichotomum Thunb, and the structures elucidated on the basis of their spectral and chemical evidences. The existence of two pairs of the C-11b epimers in the above plant were supported by the methoxide-catalyzed equilibrations of the compounds having the substituent on C-11b. Blue pigments were formed from the isolated compounds.
  • Shin-ichi Hirano, Takashi Hayashi, Masashi Miura, Hiroyuki Tomonaga
    1989 Volume 62 Issue 3 Pages 888-892
    Published: 1989
    Released: June 27, 2006
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    The chemical synthesis of a high-Tc Ba2YCu3O7–δ superconductor was investigated through the organometallic route, using Ba metal, Y(OPri)3, and Cu–alkoxides or Cu–acetylacetonate as starting materials. Chemically homogeneous submicron powders of single phase Ba2YCu3O7–δ were successfully prepared at 750 °C by controlled partial hydrolysis of metal alkoxides. The utilization of ozone for favorable decomposition of Ba2YCu3O7–δ precursors was found to have a remarkable effect on suppressing the formation of BaCO3 and lowering the formation temperature of Ba2YCu3O7–δ to about 650 °C. The single phase Ba2YCu3O7–δ ceramics exhibited superconductivity at approximately 83 K (Tc end).
  • Naoki Toshima, Hiroyuki Asanuma, Hidefumi Hirai
    1989 Volume 62 Issue 3 Pages 893-902
    Published: 1989
    Released: June 27, 2006
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    A new dry-type adsorbent for nitrogen monoxide was successfully prepared from an iron(II) salt and a chelate resin containing iminodiacetic acid moieties. The capability of adsorbing nitrogen monoxide depended greatly on the method of preparation. The very active adsorbent was prepared by mixing 31.4 mmol of iron(II) sulfate and a commercial chelate resin containing 21.0 mmol of iminodiacetic acid moieties; the mixture was dried after the solid parts had been washed with methanol. The resulting solid adsorbent could adsorb more than 99% of the nitrogen monoxide from 6 dm3 of nitrogen gas containing 1000 ppm of nitrogen monoxide within 25 min. This high capability for adsorbing nitrogen monoxide was derived from the increase in the surface area (43.1 m2 g−1) of the resin-immobilized iron(II) complex upon washing with methanol. The mechanism for the increase in the surface area is also discussed.
  • Noriyuki Sotani, Kazuo Eda, Masayasu Sadamatu, Sadao Takagi
    1989 Volume 62 Issue 3 Pages 903-907
    Published: 1989
    Released: June 27, 2006
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    Hydrogen molybdenum bronzes, HxMoO3, of Type-I (x=0.21), Type-III (x=1.55), and Type-IV (x=1.90) were prepared by the Glemser’s method. Type-II (x=0.91) was obtained from Type-III by standing in air for 120 days. The bronzes with low hydrogen contents were stable, but those with high contents were not so stable. All these bronzes have been studied by X-ray diffraction, IR spectroscopy, and TG-DTA. Bronzes with high hydrogen contents were changed upon heating in air, successively, to those with low hydrogen contents by the evolution of H2.
  • Toshiomi Shinomiya
    1989 Volume 62 Issue 3 Pages 908-914
    Published: 1989
    Released: June 27, 2006
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    The dielectric constants and losses of 28 linear alcohols, 1-alkanol (n=3–10), 2-alkanol (n=3–10), 3-alkanol (n=5–10), 4-alkanol (n=7–10), and 5-alkanol (n=9 and 10), have been measured at the frequencies from 1.35 to 4500 MHz at 15, 25, and 35 °C. The Kirkwood–Fröhlich equation was modified so that it could be applied to each dispersion region calculated. The concentration C1 of linear hydrogen-bonded chain polymers, which primary dispersion originates, was evaluated by means of this modified equation. The C1 decreases as the hydroxyl group approaches the center of a molecule, except for propanols and butanols, and also decreases with increasing temperature. For isomeric decanols, for example, the percentages of C1 (C1×100⁄C0) against alcohol gross stoichiometric concentration C0 at 15, 25, and 35 °C are about 71, 63, and 53% for 1-decanol, 52, 40, and 29% for 2-decanol, 22, 17, and 12% for 3-decanol, 11, 7, and 6% for 4-decanol, and 8, 6, and 5% for 5-decanol, respectively. The thermodynamic parameters, ΔF\ eweq, ΔH\ eweq, and ΔS\ eweq, were obtained for dipole relaxation and viscous flow . The ΔFτ\ eweq decreases, although the ΔHτ\ eweq and ΔSτ\ eweq increase, as the hydroxyl group approaches the center of a molecule. The ΔFη\ eweq increases linealy with the molecular volume, irrespective of the position of the hydroxyl group.
  • Masao Okubo, Koji Matsuo, Akira Yamauchi
    1989 Volume 62 Issue 3 Pages 915-918
    Published: 1989
    Released: June 27, 2006
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    In the reaction of p-MeC6H4N(MgBr)2 with p-alkoxynitrobenzene, no effect of alkoxyl chain length on the relative yields of azoxy and azo products was observed. In contrast, in the reaction of p-alkoxy-C6H4N(MgBr)2 with p-nitrotoluene, C12- and C18-alkoxyl chains led to the corresponding unsymmetrical azobenzenes in unexpectedly high yields. This result, arising from efficient condensation and deoxygenation processes, was explained in terms of cooperation of reagent molecules through their aggregation assisted by a novel tying effect of their long chains.
  • Toshie Harazono, Katsumi Tanaka, Yoshito Takeuchi
    1989 Volume 62 Issue 3 Pages 919-921
    Published: 1989
    Released: June 27, 2006
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    The quadrupole coupling constants in the symmetric tetrasubstituted germanes, GeR4 (R=CH3, C2H5, n-C3H7, n-C4H9, Cl, and Br) were obtained by measuring the 73Ge spin-lattice relaxation times (T1) and the reorientational correlation times (τc) of the chloroform solutions. Quadrupole coupling constants of GeR4 were in the range of 0.72 MHz (R=n-C4H9) to 1.51 MHz (R=CH3), and these decreased slightly as the molecular radius increased.
  • Shoichi Okouchi, Hisayoshi Saegusa
    1989 Volume 62 Issue 3 Pages 922-924
    Published: 1989
    Released: June 27, 2006
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    The adsorbability index proposed by Abe et al. to predict the activated carbon adsorption of organic compounds from aqueous solution was well correlated with the soil sorption coefficients of polycyclic aromatic hydrocarbons (PAHs), alkylbenzenes, chlorobenzenes, chlorinated alkanes and alkenes, heterocyclic and substituted PAHs, and halogenated phenols. The adsorbability index was also found to be well correlated with the first-order molecular connectivity index and the total molecular surface areas of these compounds.
  • Toshikazu Hieida, Masayoshi Maehara, Yoshinori Nibu, Hiroko Shimada, R ...
    1989 Volume 62 Issue 3 Pages 925-927
    Published: 1989
    Released: June 27, 2006
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    Low-frequency Raman bands ot the [1H4]- and [2H4]pyrazine crystals were studied at various temperatures between 4.2 and 300 K. All six rotational lattice vibrations were identified based on the isotopic factor (the ratio of the vibrational frequency of the [1H4]- and [2H4]pyrazine crystals) of the individual vibrations. Classification of the rotational lattice vibrations into symmetry species was made through the polarization measurement of the Raman bands in single crystals.
  • Hirotomo Hase, Guangchuan Jin, Takenobu Higashimura
    1989 Volume 62 Issue 3 Pages 928-930
    Published: 1989
    Released: June 27, 2006
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    The ultraviolet spectrum observed in γ-irradiated liquid nitrogen containing a small amount of oxygen has been ascribed to ozone. The εG value was obtained. The dose rate effect on the yield of ozone was observed. The value of εmG was inversely proportional to the square root of the dose rate. This allowed us to discuss the formation mechanism of ozone in liquid nitrogen.
  • Shinsaku Yamazaki, Tomoharu Ama
    1989 Volume 62 Issue 3 Pages 931-933
    Published: 1989
    Released: June 27, 2006
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    Variable temperature 1H NMR suggests that the metal–carbon bonded Pt(II) complex of 1,1,2,2-tetraacetylethane(dahd=3,4-diacetyl-2,4-hexadiene-2,5-diol), [Pt(dahd-C3,O′)(SEt2)2] undergoes two distinct rearrangements at the sulfides, one of which is accompanied by an anomalous dissociation process. From a comparison of the estimated kinetic parameters for inversion, an arrangement of the two sulfides in planar geometry is proposed.
  • Hideaki Takahashi, Takashi Shibahara, Yoshihisa Yamamoto
    1989 Volume 62 Issue 3 Pages 934-935
    Published: 1989
    Released: June 27, 2006
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    X-Ray photoelectron spectroscopy (XPS) was applied to three binuclear molybdenum(V) complexes of di-μ-oxo-, μ-oxo-μ-sulfido-, and di-μ-sulfido-bis[(cysteinato)oxomolybdate(V)]2−, [Mo2(μ-O)x(μ-S)yO2(cys)2]2− (x=2, y=0; x=y=1; and x=0, y=2), and the electronic state for Mo atom of the (μ-O)2 bridge, (μ-O, μ-S) bridge and (μ-S)2 bridge complexes was studied. It has been found that the binding energy of the Mo 3d5⁄2,3⁄2 peaks shifts to a lower value by at most 0.5 eV with increasing the number of μ-S bridges from 0 to 2. On the other hand, those of O 1s, C 1s, N 1s, and S 2s peaks are not significantly affected by bridge substitution. The change in the electronic state of Mo atoms is discussed in terms of the low electronegativity of the S atom.
  • Katsura Mochizuki, Yumiko Endoh
    1989 Volume 62 Issue 3 Pages 936-938
    Published: 1989
    Released: June 27, 2006
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    A new series of heterobinudear Cu(II)Ni(II) complexes with bis(tetraazamacrocycle), i.e., 7,7′-polymethylenebis[2,12-dimethyl-3,7,11,17-tetraazabicyclo[11.3.1]heptadeca-1(17),2,11,13,15-pentaene]copper(II)nickel(II) perchlorates with polymethylene bridges with a length of 2–6-C, were synthesized by a template reaction.
  • Ryoki Nomura, Kouichi Kanaya, Haruo Matsuda
    1989 Volume 62 Issue 3 Pages 939-941
    Published: 1989
    Released: June 27, 2006
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    Solution pyrolysis of Bi(S2CNRR′)3 in p-xylene or chloroform on a glass substrate at 350 °C under Ar atmosphere gave polycrystalline and low resistive (102 Ω cm in dark) bismuth sulfide thin films which showed large photoelectric effect.
  • Mitsuji Yamashita, Manabu Naoi, Hiroyuki Imoto, Tatsuo Oshikawa
    1989 Volume 62 Issue 3 Pages 942-944
    Published: 1989
    Released: June 27, 2006
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    Diphenylphosphinite derivatives of carbohydrates (L-rhamnose, D-mannitol, and cellulose), which have asymmetric centers on the skeletons were synthesized. Asymmetric hydrogenations of prochiral substrates using rhodium catalysts with the prepared chiral phosphinite ligand were carried out to obtain chiral substances in 8–78% optical yield.
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