Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
Volume 63 , Issue 12
Showing 1-50 articles out of 69 articles from the selected issue
  • Zempachi Ogumi, Toshiyuki Mizoe, Chen Zhen, Zen-ichiro Takehara
    1990 Volume 63 Issue 12 Pages 3365-3368
    Published: 1990
    Released: June 05, 2006
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    The electrochemical behavior of a manganese redox couple incorporated into an SPE (Solid Polymer Electrolyte) composite electrode using Nafion (Pt–Nafion) was examined as a mediator for electroorganic syntheses. The mediatory reaction of the redox couple was examined in the oxidation of cinnamyl alcohol. The oxidation proceeded smoothly and gave cinnamaldehyde in high selectivity; the current efficiency was as high as 85%. The dissolving-out of manganese from the SPE was suppressed by the addition of 0.025 mol dm−3 MnSO4 to the catholyte.
  • Kosaku Suga, Shigeru Fujita, Hiroshi Yamada, Masamichi Fujihira
    1990 Volume 63 Issue 12 Pages 3369-3375
    Published: 1990
    Released: June 05, 2006
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    The rate constants of intramolecular photoinduced electron-transfer reactions of a linked pyrene–viologen molecule A and a linked pyrene–ferrocene molecule B solubilized in micellar solutions of a hexadecyltrimethylammonium chloride were determined to be 9×108 and 4×108 s−1 respectively, from the stationary fluorescence intensity. However, the observed fluorescence decay curve of A suggests that a large fraction of the molecules have conformations for which the distances between two functional moieties are sufficiently small to permit direct electron transfer. The quasi-first-order rate constants of the intermolecular photoinduced electron-transfer reactions between 1-hexylpyrene (HPy) and dodecylviologen (DDV), and between HPy and butylferrocene (BFc) solubilized in a micellar solution, were also determined to be 9×106 and 2×107 s−1 respectively, from the fluorescence decay curves. It is shown that the rate constants of the intermolecular photoinduced electron-transfer reaction in micelles are determined by the diffusion of the reactants in a micelle. On the other hand, it is suggested that the rate constants of the intramolecular electron-transfer reactions are determined by the molecular conformations of the linked compounds in micelles.
  • Hisashi Uedaira, Miyuki Ishimura, Sakae Tsuda, Hatsuho Uedaira
    1990 Volume 63 Issue 12 Pages 3376-3379
    Published: 1990
    Released: June 05, 2006
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    The spin-lattice relaxation times, T1, of H217O have been measured for aqueous solutions of 2 di-, 2 trisaccharides, α-, and γ-c clodextrins as a function of the concentration at 25°C. The dynamic hydration numbers, nDHN, for 17 sugars including monosaccharides were expressed by the linear relation of the mean number of the equatorial OH groups. The second virial coefficients showed a good correlation with nDHN. Though the rotational correlation times, τch, of water molecules in the cosphere of sugar molecules increased with increasing the number of equatorial OH groups for monosaccharides, those for trisaccharides and cyclodextrins showed almost constant values. The relation between the values of the limiting diffusion coefficients and nDHN for sugars was found to be expressed by two lines with a large negative slope for mono- and di- saccharides, and a small negative slope for trisaccharides and cyclodextrins.
  • Hirokazu Miyoshi, Satoru Nippa, Hiroyuki Uchida, Hirotaro Mori, Hirosh ...
    1990 Volume 63 Issue 12 Pages 3380-3384
    Published: 1990
    Released: June 05, 2006
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    TiO2 microcrystallites of different sizes were prepared in Nafion and the energy diagrams of these were determined from the onset potential of photocurrents due to oxidation of tartrate ions and the bandgap energy which was estimated from absorption spectra. The smallest particle prepared in the present study had the diameter less than 2 nm and the bandgap energy of 3.95 eV. Photocatalytic activities of the TiO2 microcrystallites prepared in Nafion for photodecomposition of acetic acid were very low compared to those of TiO2 microcrystallites prepared in clay interlayers and were comparable to those of the latter photocatalysts obtained in the presence of SO42−, suggesting that sulfonate groups of Nafion made the photocatalytic activity of TiO2 microcrystallites decrease.
  • Hiroshi Miyasaka, Kazuhiro Morita, Kenji Kamada, Noboru Mataga
    1990 Volume 63 Issue 12 Pages 3385-3397
    Published: 1990
    Released: June 05, 2006
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    Photoreduction processes of excited benzophenone (BP) by N,N-dimethylaniline (DMA) in acetonitrile solution were studied by means of picosecond-femtosecond laser photolysis and time resolved transient absorption spectroscopy as well as transient photoconductivity measurement. Proton transfer process in the triplet ion pair formed by electron transfer (ET) at encounter between 3BP* and DMA, competing with the ionic dissociation process was observed. It was clearly demonstrated that, in addition to the triplet ion pair, the ion pair produced by the excitation of the CT complex between BP and DMA formed in the ground state and that produced by ET reaction between 1BP* and DMA played important roles in the reaction processes of excited benzophenone. The behaviors of the three kinds of ion pairs were investigated in detail, leading to the elucidation of reaction mechanism of each ion pair. The reactivity characteristic of each kind of the ion pair and its relation to the structure of the ion pair were discussed.
  • Katsunori Kohata, Yoshiaki Kawamonzen, Tsugikatsu Odashima, Hajime Ish ...
    1990 Volume 63 Issue 12 Pages 3398-3404
    Published: 1990
    Released: June 05, 2006
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    Four new water-soluble hydrazones, α-(5-nitro-2-pyridyl)hydrazono-α-(2-quinolyl)-3-toluenesulfonic acid, α-(5-nitro-2-pyridyl)hydrazono-α-(2-thiazolyl)-3-toluenesulfonic acid, α-(2-benzothiazolyl)-α-(5-nitro-2-pyridyl)hydrazono-3-toluenesulfonic acid, and α-(2-benzimidazolyl)-α-(5-nitro-2-pyridyl)hydrazono-3-toluenesulfonic acid, were synthesized. Their proton dissociation constants were determined spectrophotometrically. The chromogenic properties of the synthesized hydrazones and their reactions with metal ions were investigated spectrophotometrically in detail. The results revealed that the synthesized hydrazones react with various metal ions including transition metal ions, especially with cadmium(II), nickel(II), and zinc(II) to form stable colored complexes with very large apparent molar absorptivities, so that they were found to be all very useful as highly sensitive spectrophotometric reagents.
  • Hajime Ishii, Tsugikatsu Odashima, Yoshiaki Kawamonzen
    1990 Volume 63 Issue 12 Pages 3405-3409
    Published: 1990
    Released: June 05, 2006
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    The complexation reaction of four water-soluble hydrazones, α-(5-nitro-2-pyridyl)hydrazono-α-(2-quinolyl)-3-toluenesulfonic acid (NPHQTS), α-(5-nitro-2-pyridyl)hydrazono-α-(2-thiazolyl)-3-toluenesulfonic acid (NPHTTS), α-(2-benzothiazolyl)-α-(5-nitro-2-pyridyl)hydrazono-3-toluenesulfonic acid (BTNPHTS) and α-(2-benzimidazolyl)-α-(5-nitro-2-pyridyl)hydrazono-3-toluenesulfonic acid (BINPHTS), with nickel(II) has been studied spectrophotometrically. These hydrazones react with nickel(II) to form a stable 1:2 (metal: ligand) complexes with high molar absorptivities. A sensitive and selective spectrophotometric method for the determination of nickel with BINPHTS has been developed. The nickel–BINPHTS complex is formed quantitatively in the pH range 6.5–8.9 and its absorption spectrum shows a maximum at 498 nm. Beer’s law is obeyed over the range 0.02–0.8 μg cm−3 of nickel and the apparent molar absorptivity of the complex is 8.67×104 dm3mol−1cm−1 at 498 nm. The proposed method was applied to the determination of nickel in manganese nodule samples, satisfactory results being obtained. Furthermore, the overall formation constants of nickel complexes of the four hydrazones were also determined spectrophotometrically.
  • Masanobu Tsuchimoto, Masakazu Kita, Junnosuke Fujita
    1990 Volume 63 Issue 12 Pages 3410-3413
    Published: 1990
    Released: June 05, 2006
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    The electronic spectra of trans-[CoCl2(NH3)4]Cl and its analogues measured in the solid state at 113 K show four ligand field bands assignable to the Ia(1Ega1A1g), Ib(1A2g1A1g), IIa(1B2g1A1g), and IIb(1Egb1A1g) transitions in D4h approximation. The ligand field parameters obtained from the observed data are; eσ(N)=7400–8000 cm−1, eσ(Cl)=4500–5400 cm−1, eπ(Cl)=300–830 cm−1, and the Racah’s parameter C estimated with the assumption of C=4B is ca. 2000 cm−1. A nearly linear relationship is obtained between the eσ(Cl) and eπ(Cl) values; the stronger the coordination of Cl to Co(III), the stronger the π interaction of Cl with Co(III).
  • Satoshi Kawata, Hiroshi Yokoi, Masamoto Iwaizumi
    1990 Volume 63 Issue 12 Pages 3414-3419
    Published: 1990
    Released: June 05, 2006
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    Binuclear copper(II) complexes of 3,12-bis(carboxymethyl)-6,9-dioxa-3,12-diazatetradecanedioic acid have been investigated by EPR. It has been confirmed that three different binuclear complexes are formed, depending on the pH of the solution. The complex formed in the low pH region has a copper–copper distance of 5.5 Å and a weak magnetic dipolar interaction. The other two are of olated forms with strong magnetic interactions between the copper atoms through oxygen bridges. One of them has an antiferromagnetic interaction; though the other has a weak antiferromagnetic interaction, it shows a large zero-field splitting. Such differences between the magnetic properties of the two olated complexes are attributed to a difference in the bridged style, i.e., the former is a mono-μ-hydroxo-bridged complex and the latter is a double-μ-hydroxobridged complex.
  • Tamas Radnai, Kenta Inoue, Hitoshi Ohtaki
    1990 Volume 63 Issue 12 Pages 3420-3425
    Published: 1990
    Released: June 05, 2006
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    The structures of mono(α-alaninato)zinc(Il), bis(α-alaninato)zinc(II), and tris(α-alaninato)zincate(II) complexes in aqueous solutions were determined by the X-ray diffraction method. All the three complexes have the octahedral structure in the form [Zn(α-ala)(H2O)4]+, [Zn(α-ala)2(H2O)2], and [Zn(α-ala)3]. The structures of the complexes were different from those of the glycinato complexes of zinc(II) ion, which were all regular octahedral. The length of the Zn–O bond in the α-alaninato complexes was shorter than that of the Zn–N bond due to the inductive effect of the substituted methyl group at the α-carbon on the oxygen atom in the amino acid. The lengths of the Zn–O and Zn–N bonds in the complexes determined are, respectively, as follows: [Zn(α-ala)(H2O)4]+, 202 and 214 pm; [Zn(α-ala)2(H2O)2], 203 and 214 pm; [Zn(α-ala)3], 202 and 213 pm.
  • Kenji Waizumi, Hideki Masuda, Hitoshi Ohtaki, Katsuo Tsukamoto, Ichiro ...
    1990 Volume 63 Issue 12 Pages 3426-3433
    Published: 1990
    Released: June 05, 2006
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    Transformation among cobalt(II) dichloride hydrates in aqueous solutions was studied by the optical microscopic method. Although there are three hydrates (CoCl2·6H2O, CoCl2·4H2O, and CoCl2·2H2O) in the phase equilibrium diagram, the only solution mediated transformation between CoCl2·6H2O and CoCl2·2H2O could be observed under the present experimental conditions and it was confirmed that CoCl2·4H2O hardly formed compared with the other two hydrates. In order to investigate the reason why CoCl2·4H2O was hardly crystallized at the transformation from CoCl2·6H2O through CoCl2·2H2O and vice versa, the crystal structure of CoCl2·4H2O was investigated by the X-ray diffraction method. The structure of CoCl2·6H2O was reexamined because previously reported results had a relatively large R-factor. The crystal of CoCl2·4H2O is monoclinic, space group P21/a with a=11.548(1) Å, b=9.342(1) Å, c=6.056(1) Å, β=110.79(1)°, and Z=4. The complex has a slightly distorted octahedral geometry about Co2+ ion and two Cl ions are located at the cis-position. The crystal of CoCl2·6H2O is monoclinic, space group C2/m with a=10.380(2) Å, b=7.048(1) Å, c=6.626(1) Å, β=122.01(1)°, and Z=2. The geometry around the cobalt ion is also octahedral with four water molecules and two chloride ions at the equatorial and the axial positions, respectively. The remaining two water molecules are linked to the two Cl ions by hydrogen bonding. The difficulty of crystallization of CoCl2·4H2O crystals in solutions was explained in terms of the relatively unstable cis-dichloro structure of the [CoCl2(H2O)4] moiety and its crystal structure stabilized by hydrogen bonding network between the cis-form moieties.
  • Takayoshi Suzuki, Masakazu Kita, Kazuo Kashiwabara, Junnosuke Fujita
    1990 Volume 63 Issue 12 Pages 3434-3442
    Published: 1990
    Released: June 05, 2006
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    The complexes [MX2(PMe2py-P)2] (M=Pd(II), Pt(II); X=Cl, Br, and I) have been synthesized and characterized both in the solid state and in solution by their infrared and 1H, 13C, and 31P NMR spectra, in addition to an X-ray crystallographic analysis of cis-[PdCl2(PMe2py-P)2]. The latter complex exists as a cis–trans equilibrium mixture in solution, while only the cis isomer has been isolated in the solid state. The [PdBr2(PMe2py-P)2] complex which has been isolated as the trans isomer shows also the same isomerization in solution, in contrast to [PdBr2(PMe2Ph)2] which exists only as the trans isomer both in the solid state and in solution. Furthermore, PMe2py has been found to have the ability for chelation via the nitrogen and phosphorus atoms to make a four-membered chelate ring. The chelate ring in the complexes [PdX(PMe2py)2]Y (X=Cl, Br, and I; Y=ClO4, PF6) has been confirmed by infrared spectra and X-ray analysis of cis(P,P)-[PdCl(PMe2py-P,N)(PMe2py-P)]ClO4. This is the first example in which PMe2py is acting as a chelating ligand.
  • Manabu Fujiwara, Hisanobu Wakita, Takayuki Matsushita, Toshiyuki Shono
    1990 Volume 63 Issue 12 Pages 3443-3449
    Published: 1990
    Released: June 05, 2006
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    14-,18-, and 22-membered tetraaza macrocycles have been prepared by the reaction of acetylacetone with ethylenediamine, 1,4-butanediamine, or 1,6-hexanediamine, respectively. Their copper(II) and nickel(II) complexes were characterized by electronic and infrared spectroscopies. The 14-membered macrocycle forms a mononuclear copper(II) complex with a planar structure, whereas the 18-membered macrocycle forms a mononuclear copper(II) complex with a pseudo-tetrahedral structure, and the 22-membered macrocycle forms di- and trinuclear copper(II) complexes. The complexation and extraction abilities of these macrocycles toward copper(II) and nickel(II) ions are discussed.
  • Yue Wu, Kazunari Ishibashi, Toshio Deguchi, Isao Sanemasa
    1990 Volume 63 Issue 12 Pages 3450-3455
    Published: 1990
    Released: June 05, 2006
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    The vapor saturation method was applied to prepare aqueous solutions saturated with a volatile solid solute such as fluorene, fluoranthene, or pyrene. Henry’s law was found to hold for their aqueous solubility, and sublimation enthalpy was evaluated for each solid solute. Complex formation constants with cyclodextrins at 25°C have been determined by the vapor saturation method. The applicability and limitation of the method are discussed.
  • Kenichi Somekawa, Tetsuro Shimo, Hiroyuki Yoshimura, Takaaki Suishu
    1990 Volume 63 Issue 12 Pages 3456-3461
    Published: 1990
    Released: June 05, 2006
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    Sensitized photoreactions of two 2-pyrones with five unsaturated compounds were investigated. The reactions of 2-pyrones with electron-deficient ethylenes gave [4+2]cycloadducts (3) and [2+2]cycloadducts (4) across the C5–C6 double bonds in the 2-pyrones. On the other hand, reactions with an electron-donating ethylene, ethyl vinyl ether (2i), gave other kinds of [2+2]cycloadducts (5) and a [4+2]cycloadduct (6), site- and regio-selectively. These two kinds of reactions were inferred to start at the C-6 and C-4 positions of the 2-pyrones to give 3 or 4, and 5 or 6, respectively. The regioselectivity of 6 was opposite to that for a thermal [4+2]cycloadduct (7). The substituents on 2-pyrones also influenced the product-distribution and the triplet energy-level.
  • Kazuhiro Maruyama, Hiroko Yamada, Atsuhiro Osuka
    1990 Volume 63 Issue 12 Pages 3462-3466
    Published: 1990
    Released: June 05, 2006
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    We applied the Chemically Induced Dynamic Nuclear Polarization (CIDNP) technique to the photochemical reaction of pheophytin a (P1) and 4-methoxyphenol (1) in benzene-d6. The observed CIDNP effects were explained in terms of reversible electron-transfer reactions from 1 to 3(P1)* and from (P1)\ ewdot to (1)\underset.+. The polarized signals of P1 were induced from the in-cage recombination of the triplet radical ion pair.
  • Ken-ichi Satoh, Hirofumi Okuda, Hideaki Horimoto, Hiroaki Kodama, Mich ...
    1990 Volume 63 Issue 12 Pages 3467-3472
    Published: 1990
    Released: June 05, 2006
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    In order to investigate the relationship between the structure of a peptide backbone and the formation of an intramolecular disulfide bond (S–S) in the peptide, a linear analog (1) of gramicidin S and a heterodetic cyclic peptide containing an S–S bond (2) were synthesized by the conventional solution method. Since a disulfide bonded compound (2) was easily formed by a treatment of the acetamidomethyl(Acm)-protected linear peptide (1) with iodine in good yield (70%), it is suggested that the mutual position between Cys1 and Cys8 residues becomes approximate, owing to the contribution of –D-Phe–Pro– part of the sequence. A heterodetic cyclic peptide (2) showed about 1/16–1/8 fold activity compared to that of GS; 1 as inactive. By the construction of an S–S bridge on the peptide backbone (1), an inactive peptide derivative was effectively converted to an active analog (2). The CD spectrum pattern also suggests that the heterodetic cyclic peptide (2) has a GS-like structure.
  • Hideya Yuasa, Akio Takenaka, Hironobu Hashimoto
    1990 Volume 63 Issue 12 Pages 3473-3479
    Published: 1990
    Released: June 05, 2006
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    5-Thio-α-D-glucopyranose derivatives were oxidized with 3-chloroperoxybenzoic acid in various conditions to give axial and equatorial sulfoxides. Structure of an axial sulfoxide obtained was determined by X-ray crystallography. Configuration of other sulfoxides was determined by 1HNMR spectroscopy according to empirical rules of chemical shift. The anomeric substituent was decisive for the stereoselectivity and the ratios of axial to equatorial sulfoxide were 3–11.5 for methoxy derivatives and 0.4–1.0 for acetoxy derivatives.
  • Koji Araki, Koji Iwamoto, Seiji Shinkai, Tsutomu Matsuda
    1990 Volume 63 Issue 12 Pages 3480-3485
    Published: 1990
    Released: June 05, 2006
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    The acid dissociation constants (Kapp) of p-t-butylcalix[n]arenes (1n: n=4, 6, and 8), O-methylated p-t-butylcalix[4]arene (2Men), and their noncyclic analogs (3n) were estimated in THF at 25°C. As pH indicators, Et4N+ salts of p-nitrophenolate, 2,4-dinitrophenolate, and picrate were employed. The pKapp values for 1n were lowered by at least four pK units from that of p-t-butylphenol because of strong intramolecular hydrogen-bonding interactions. Compounds 2n involved both the strong and weak hydrogen bonds: the proton in the strong hydrogen bond showed the acidity comparable with that of 1n whereas that in the weak hydrogen bond showed the relatively high pKapp. These properties were discussed in relation to δOH (chemical shift in 1HNMR) and νOH(OH vibration band in IR). This is the first systematic discussion on “pKa” of p-t-butylcalix[n]arenes.
  • Yoichi Taguchi, Isao Shibuya, Masahiko Yasumoto, Tohru Tsuchiya, Katsu ...
    1990 Volume 63 Issue 12 Pages 3486-3489
    Published: 1990
    Released: June 05, 2006
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    The trimerization of phenyl isocyanate in the presence of triethylamine was accelerated under high pressure to give triphenyl isocyanurate almost quantitatively. The reaction in benzene was remarkably accelerated by compression. The effects of pressure, temperature, catalysts, and solvents were examined on the trimerization of phenyl isocyanate. Aryl and normal alkyl isocyanates trimerized under high pressure to give the corresponding isocyanurates in good yields, whereas isocyanates having bulky alkyl groups such as t-butyl and cyclohexyl did not trimerize even under 800 MPa.
  • Masami Shibukawa, Naoichi Ohta, Nobuhiko Onda
    1990 Volume 63 Issue 12 Pages 3490-3494
    Published: 1990
    Released: June 05, 2006
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    A new liquid chromatographic method was proposed for the estimation of the amount of water which exhibits selectivity to solutes in water-swollen hydrogels based on the model regarding the retention of ions on the column packed with the hydrogels. The estimated amount of the water in polyacrylamide, dextran, and poly(vinyl alcohol) gels corresponds to the sum of the amount of freezable bound water and that of nonfreezing water determined by means of differential scanning calorimetry. This means that the freezable bound water takes an important role in the separation process using water-swollen hydrogels contrary to the conventional view of the freezable water.
  • Masanori Koshioka, Hirokazu Mizuma, Keiji Imagi, Noriaki Ikeda, Hirosh ...
    1990 Volume 63 Issue 12 Pages 3495-3501
    Published: 1990
    Released: June 05, 2006
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    A microcomputer-controlled nanosecond diffuse reflectance laser photolysis system was developed and applied to p-terphenyl powder systems. The triplet absorption spectrum of microcrystalline powders is broader and red-shifted compared to the molecular triplet state in solution. Possible contributions of an optical artifact and an impurity were rejected by examining powder systems doped with naphthacene and diluted with NaCl as well as poly(methyl methacrylate). p-Terphenyl adsorbed on silica gel and included in β-cyclodextrin gave different triplet spectra, which are interpreted in terms of conformational structure of p-terphenyl. Decay processes and an oxygen effect are also discussed.
  • Isamu Miyata, Akira Takada, Masakatsu Yonese, Hiroshi Kishimoto
    1990 Volume 63 Issue 12 Pages 3502-3507
    Published: 1990
    Released: June 05, 2006
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    The electric conductivities of sodium dodecyl sulfate (SDS) in methanol and water were measured at 298 K in a concentration range up to 10 mmol dm−3. The values of the limiting molar conductivities of SDS, Λ0, in methanol and water were estimated to be 81.5 and 74.0 S cm2mol−1, respectively, and compared with each other. From those values and the values of NaCl in both solvents, the limiting molar conductivities of dodecyl sulfate ion in methanol and water were estimated to be 36.27 and 23.90 S cm2mol−1, respectively. Also, the vapor-pressure depression of SDS in methanol was measured at 298 K in the concentration range up to 42 mmol kg−1. From the results, and according to the theory regarding strong electrolytes, the mean ionic activity coefficient, γ±, of SDS in methanol at 298 K was calculated. Further, the solubility and heat of solution of SDS in methanol at various temperatures and at 298 K, respectively, were measured. From a thermodynamic analysis of these results, the theoretical relation between lnγ± and m was obtained over the range of temperatures 285–295 K.
  • Shoichiro Yoshida, Tadashi Watanabe
    1990 Volume 63 Issue 12 Pages 3508-3515
    Published: 1990
    Released: June 05, 2006
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    A competitive proton-driven transport of alkali metal ions with co-transported picrate anion was investigated in a chloroform membrane system containing either dicyclohexano-18-crown-6 (DCl8C6), octadecylamine (C18NH2), or a DCl8C6/C18NH2 mixture as cooperative carrier. The cooperative carrier effectively transported K+ against its concentration gradient between the two aqueous phases. The DCl8C6 alone, though being a proton-unionizable carrier, also mediated the uphill transport of K+ when the receiving phase was strongly acidic. The mechanisms for these transport behaviors are discussed referring to additional data on the partitioning of species at membrane/aqueous phase interfaces.
  • Kazunori Matsui, Naomi Usuki
    1990 Volume 63 Issue 12 Pages 3516-3520
    Published: 1990
    Released: June 05, 2006
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    The fluorescence and excitation spectra of pyrene at high concentrations were studied along the sol to xerogel stages of the sol–gel silica formed by the acidic hydrolysis of tetraethyl orthosilicate. The monomer and excimer fluorescence of pyrene were observed in the reaction system. Their relative intensities revealed that complex changes occurred that depended on the reaction time and the excitation wavelengths. The environmental polarity of the probe molecules also changed as shown by the fluorescence vibronic structure. The excitation spectrum of the excimer fluorescence in some stages was red shifted in comparison with that of the monomer fluorescence, indicating the existence of bimolecular ground-state pyrene associations. The mechanism by which pyrene molecules are trapped in the silica network is discussed on the basis of the results.
  • Yoshihiro Sasaki
    1990 Volume 63 Issue 12 Pages 3521-3527
    Published: 1990
    Released: June 05, 2006
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    One tentative reaction network for the bromate–bromide–tris(1,10-phenanthroline)iron(II) (ferroin) system in an acidic medium was examined by means of a simulation method, which involved the Field–Körös–Noyes scheme, the reduction of HBrO2 and HOBr by ferroin via two-electron transfer processes and the reactions of Fe(phen)22+ with BrO3, HBrO2, HOBr, and BrO2·. The network successfully reproduced the behavior of the system in a batch reactor. The behavior of the system in a continuous-flow stirred tank reactor (CSTR) was simulated under two CSTR conditions: 1) Bromide flowed into the CSTR, and 2) bromide did not flow into the CSTR. Under the former condition, the system exhibited bistability and sustained oscillations. The calculated oscillations were of small amplitude and high frequency. Under the latter condition, the system exhibited bistability.
  • Masahiko Arai, Yoshiyuki Nishiyama
    1990 Volume 63 Issue 12 Pages 3528-3534
    Published: 1990
    Released: June 05, 2006
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    The catalysis of adsorbed dodecacarbonyltriiron(0) was used to develop the pore structure of a carbon through its partial gasification with hydrogen. The catalytic gasification at 500 °C increased the volumes of pores, in particular those of 3–5 nm in diameter. In contrast, such an effect was not observed when iron(III) nitrate was used as a catalyst. The adsorbability of hydrogen on carbon-supported iron particles obtained after gasification was examined by temperature-programed desorption (TPD). The TPD spectrum of hydrogen, in particluar, at temperatures above 200 °C, for a cluster-derived sample differed from that for a nitrate-derived sample. In addition, the apparent activation energy for the desorption of hydrogen in a low-temperature peak at around 90 °C for the former sample was larger than that for the latter. Heat treatments caused the TPD characteristics of the cluster-derived sample to become very similar to those of the nitrate-derived sample.
  • Hiroshi Kawaguchi, Naomi Uchiyama, Tomoharu Ama, Takaji Yasui
    1990 Volume 63 Issue 12 Pages 3535-3541
    Published: 1990
    Released: June 05, 2006
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    Isomerization reactions of the [Co(edda)(en)]+ and [Co(edda)(gly)] systems were studied in a basic aqueous solution. Λ(R)-β-[Co(edda)(en)]+ isomerized to the Λ(S,S)-α-isomer with an optical purity (o.p.) of ca. 45%. In the reactions of three isomers of [Co(edda)(gly)], Λ(R)-β-fac(O) isomerized to Λ(R)-β-mer(O) (o.p.: ca. 100%) and Λ(S,S)-α-mer(O) (o.p.: ca. 33%), Λ(R)-β-mer(O) to Λ(R)-β-fac(O) (o.p.: ca. 65%) and Λ(S,S)-α-mer(O) (o.p.: ca. 40%), and Λ(S,S)-α-mer(O) to Λ(R)-β-fac(O) (o.p.: ca. 50%) and Λ(R)-β-mer(O) (o.p.: ca. 60%). These results were explained on the basis of a Co–O bond-rupture mechanism.
  • Hiromichi Yamada, Shiho Horikawa, Yukio Fujii, Masateru Mizuta
    1990 Volume 63 Issue 12 Pages 3542-3549
    Published: 1990
    Released: June 05, 2006
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    Through the solvent extraction of copper(II) with the three isomeric chlorobenzoic acids in 1-octanol, it has been shown that the entrance of chloro substituent into the three positions in the benzene ring of benzoic acid results in an individuality in the extraction behavior for copper(II). The dimeric copper(II) chlorobenzoates CU2A4 and Cu2A4(HA)2 were responsible for the extraction with m-chlorobenzoic acid together with the monomer CuA2, while only the monomeric species CuA2 was extracted with o- and p-chlorobenzoic acids. The entrance of chloro group into the ortho position in benzoic acid was found to result in a lowering of both the partition constants of o-chlorobenzoic acid itself and its copper(II) compound. That into the para position has led to a significant decrease in the solubilities of the para isomer and its copper(II) compound in both aqueous and octanol phases.
  • Gaku Yamamoto, Michinori Oki
    1990 Volume 63 Issue 12 Pages 3550-3559
    Published: 1990
    Released: June 05, 2006
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    Dynamic 1H NMR study was made on several 1-substituted 8,13-dichloro-9-methyltriptycenes and 8-chloro-13-fluoro-9-methyltriptycenes to examine the effect of the peri-substituents on the rotational barrier of the 9-methyl group. The rotational barrier height increases in the expected order as the 1-hydrogen is replaced by a bulkier group up to CH3, but shows a very low value when a t-butyl group is introduced into 1-position to show that destabilization of the ground state by the bulky t-butyl group exceeds that of the transition state for rotation.
  • Hajime Nagano, Hiroko Sugihara, Noriko Harada, Natsuko Fukuchi, Keiko ...
    1990 Volume 63 Issue 12 Pages 3560-3565
    Published: 1990
    Released: June 05, 2006
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    Autoxidation of (11S)-12-hydroxy-7α-eudesmane-3,6-dione in the presence of p-toluenesulfonic acid gave 6,12-epoxy-11β-eudesma-4,6-dien-3-one, which was oxidized with m-chloroperoxybenzoic acid to give (11R)-7α,12-dihydroxyeudesm-4-ene-3,6-dione. Transformation of some other 12-hydroxyeudesman-6-ones into 7,12-dihydroxyeudesman-6-ones was also examined.
  • Hiroki Kimoto, Kazuhiko Saigo, Nobuhiro Kihara, Mami Ohno, Tsuneo Hira ...
    1990 Volume 63 Issue 12 Pages 3566-3570
    Published: 1990
    Released: June 05, 2006
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    Molecular dynamics calculation was performed in order to obtain structural information about the complexes of a macrotricyclic receptor (1), which has crown ether and cyclophane subunits as binding sites, with organic substrates, ω-(phenylalkyl)ammonium picrates (2; the methylene number, n=4, 5, 7), taking account of solvent effect. The resulting equilibrium structures were in good agreement with experimental data; among the three complexes, the complex of 1 with 2 (n=5) gave the largest stability constant. Furthermore, the quantitative evaluation of the difference in Gibbs free energy between two complexes, calculated by the perturbation method, was also consistent with the experimental data.
  • Akikazu Kakehi, Suketaka Ito, Tsuneo Fujii, Tosio Sakurai, Kunio Urush ...
    1990 Volume 63 Issue 12 Pages 3571-3578
    Published: 1990
    Released: June 05, 2006
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    The title compounds were prepared smoothly in moderate yields by the reactions of 3-(mercaptomethylene)-2(3H)-indolizinones with various alkylating agents such as bromoacetonitrile, bromoacetates, and phenacyl bromides in the presence of base. The structural assignments of these products were accomplished by their spectral inspections, and the structure for one compound was distinctly proven by its X-ray crystallography. In order to explain the regioselectivity in this reaction, a molecular orbital calculation (CNDO/2) was also performed using a model compound.
  • Hiroshi Yoshida, Keisuke Yoshida, Hiroyuki Totani, Tsuyoshi Ogata, Kiy ...
    1990 Volume 63 Issue 12 Pages 3579-3582
    Published: 1990
    Released: June 05, 2006
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    The reaction of diphenylcyclopropenone oxime (1a) with acetyl or tosyl isocyanate, carboxylic anhydrides, or nitrohalobenzenes yielded the cyclopropenone O-substituted oxime derivatives. Treating with thionyl bromide and chloride 1a gave 3-haloacrylonitriles. Whereas 1a as well as other cyclopropenone oximes, were stable under acidic conditions, heating in methanolic sodium hydroxide gave the ring-opened α,α-dimethoxyketones oximes.
  • Eijiro Umemura, Tsutomu Tsuchiya, Sumio Umezawa
    1990 Volume 63 Issue 12 Pages 3583-3589
    Published: 1990
    Released: June 05, 2006
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    3′,4′,6′-Trideoxy-6′-fluorokanamycin C (5) has been prepared by treatment of a protected kanamycin C derivative having the free 6-hydroxyl group with DAST, as the key step. Two 3′,4′-dideoxy-6′-C-(fluoromethyl)kanamycin B′s (17a and 17b) have been prepared from a 5′-C-aldehyde derivative of kanamycin C through a sequence of reactions involving nitromethane condensation and 6′,7′-(N-tosylepimino)-ring opening with KHF2, as the key steps. 1-N-[(S)-4-Amino-2-hydroxybutanoyl] derivatives of 5 and 17a were prepared by coupling of the [(S)-4-amino-2-hydroxybutanoyl] residue to the 1-amino group of 5 and 17a by utilizing the zinc acetate-ethyl trifluoroacetate method. Biological effects caused by the introduction of the fluorine atom in these products were discussed based on the chemical character of fluorine.
  • Tadashi Hanaya, Akihiko Miyoshi, Ayashi Noguchi, Heizan Kawamoto, Marg ...
    1990 Volume 63 Issue 12 Pages 3590-3594
    Published: 1990
    Released: June 05, 2006
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    2,3-O-Isopropylidene-D-glyceraldehyde reacts with dimethylphosphine oxide in the presence of triethylamine to give separable (1S,2R)-and (1R,2R)-1-dimethylphosphinylgrycerol (65 :35), from which the (1R) and (1S) title compounds are respectively derived via 1-O-mesyl and 1-azido derivatives. The corresponding 1-dimethoxyphosphinylglycerols are similarly prepared. Structural and conformational assignments of these products are made on the basis of the 1H NMR data and [α]D values.
  • Saburo Nakanishi, Yoshio Otsuji, Keiji Itoh, Nobuaki Hayashi
    1990 Volume 63 Issue 12 Pages 3595-3600
    Published: 1990
    Released: June 05, 2006
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    α-Bromooximes such as α-bromoacetophenone oxime and ethyl 3-bromo-2-(hydroxyimino)propanoate react with enamines to give 5,6-dihydro-4H-1,2-oxazines in good yields. Dihydro-1,2-oxazine derivatives are also obtained by the reaction of α-bromooximes with vinyl ethers and silyl enol ethers in the presence of Na2CO3. Dihydro-1,2-oxazines can be converted into pyrrole derivatives via reductive deoxygenation by treating with Fe3(CO)12 in moderate to excellent yields. Iron carbonyl complexes other than Fe3(CO)12 are also effective for the pyrrole-forming reaction. The efficiency of the complexes for this reaction decreases in the order: Fe3(CO)12>>Et3NH[HFe3(CO)11]>Fe2(CO)9>>Fe(CO)5. Both of the dihydro-1,2-oxazine- and pyrrole-forming reactions can be carried out in a single flask, giving pyrrole derivatives in good yields.
  • Nobuhiro Yahata, Makoto Fujita, Katsuyuki Ogura
    1990 Volume 63 Issue 12 Pages 3601-3605
    Published: 1990
    Released: June 05, 2006
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    For preparation of 5-monosubstituted or 5,5-disubstituted 2,4-dienals, 1-(methylthio)-5-(p-tolylsulfonyl)-1,3-pentadiene (4) is revealed to be an important precursor. When 5-(methylthio)-5-(p-tolylsulfonyl)-1,3-pentadiene, that is easily obtainable from (methylthio)methyl p-tolyl sulfone, was treated with silica gel, 1,5-rearrangement of p-tolylsulfonyl group occurred to give 4. The conditions for mono- or dialkylation of 4 followed by hydrolysis leading to the dienals are described.
  • Ryo Aburatani, Yoshio Okamoto, Koichi Hatada
    1990 Volume 63 Issue 12 Pages 3606-3610
    Published: 1990
    Released: June 05, 2006
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    3,5-Dimethylphenylcarbamates of oligosaccharides and cyclodextrins were synthesized and their chiral recognition abilities were evaluated as chiral stationary phases for high-performance liquid chromatography. In case of the carbamates of linear maltooligosaccharides, the optical resolution abilities of 4–7-mer were similar to each other and were not so different from the ability of amylose tris(3,5-dimethylphenylcarbamate). The chiral recognition abilities of the carbamates of cellooligosaccharides were lower than that of the cellulose tris(3,5-dimethylphenylcarbamate). The intensities of the CD spectra of the cellooligosaccharide derivatives were smaller than that of the cellulose derivative. These results suggest that the less ordered structure of the cellooligosaccharide derivatives may be correlated to the lower chiral recognition. On the other hand, 3,5-dimethylphenylcarbamates of cydodextrins showed quite different optical resolution abilities from that of amylose tris(3,5-dimethylphenylcarbamate), probably because of a quite different high-order structure.
  • Ichiro Tanahashi, Akihiko Yoshida, Atsushi Nishino
    1990 Volume 63 Issue 12 Pages 3611-3614
    Published: 1990
    Released: June 05, 2006
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    The electrochemical properties of phenolic resin-based activated carbon fiber cloth (ACFC) in an aqueous electrolyte and in a nonaqueous organic electrolyte have been investigated. The differential electric double-layer capacitance of ACFC with the specific surface area of 1630 m2 g−1 in the aqueous electrolyte was 1.50-times larger than that of the ACFC in the organic electrolyte. In accordance with the result, the capacitance of capacitors consisted of the ACFC and the aqueous electrolyte was 1.47-times larger than that of capacitors comprising ACFC and the organic electrolyte. The IR drop of capacitors with the aqueous electrolyte was smaller by one order of magnitude than that of capacitors with the organic electrolyte.
  • S. I. Ali, Harpal Kaur
    1990 Volume 63 Issue 12 Pages 3615-3618
    Published: 1990
    Released: June 05, 2006
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    The kinetics of the reactions of photochemically generated [W(CN)7OH]4− in basic and [HW(CN)7(H2O)]2− in acidic medium with 1,10-phenanthroline have been studied in buffer solutions of pH 4.2–10.6, ionic strength 7.5×10−2 mol kg−1 at 20°C. Quantum yield for formation of photoproduct was calculated and it was found to depend on pH, ligand and, [W(CN)8]4− concentrations. The pseudo-first-order rate constant and quantum yield values in acidic medium are higher than in basic medium and the mechanisms of the photochemical substitution reactions are different in two mediums.
  • M. S. K. Niazi, J. Ali
    1990 Volume 63 Issue 12 Pages 3619-3624
    Published: 1990
    Released: June 05, 2006
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    The thermodynamic dissociation constants and the limiting molar conductivities of 2-, 3-, and 4-nitrobenzoic and benzoic acids have been determined in water–acetonitrile mixtures at 298 K. It is found that the acids dissociate in the dereasing order as 2-nitrobenzoic acid > 3-nitrobenzoic acid≈4-nitrobenzoic acid > benzoic acid. The conductance–concentration data were analyzed with the Lee and Wheaton equation. The present results are compared with the previous ones for these acids in alcohol–water system, and are interpretted in terms of solute–solvent interactions, intramolecular hydrogen bondings, resonance and inductive effects along with the substituent position.
  • Ivan Pinto, B. S. Sherigara, H. V. K. Udupa
    1990 Volume 63 Issue 12 Pages 3625-3631
    Published: 1990
    Released: June 05, 2006
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    Conditions have been established for the electrogeneration of Mn(III) from Mn(II) in sulfuric acid medium. Mn(III) formed was identified and characterized by UV spectra. Kinetics of Mn(III) oxidation of L-histidine in aqueous sulfuric acid medium has been studied spectrophotometrically. Oxidation followed second order kinetics in [Mn(III)], first order in [histidine] and increase in [H+] decreased the rate. The reduced product of the oxidant, Mn(II), retarded the rate of reaction. Evidence for the transient existence of the free radical reaction intermediate is given. Effects of ionic strength, solvent composition, HSO4 and certain complexing agents like P2O74−, Cl, F, have also been studied. Added complexing agents decreased the redox potential of the Mn(III)/Mn(II) couple, thereby reducing the oxidation rate. Dependence of reaction rate on temperature is examined and activation parameters computed from Arrhenius and Eyring plots. A mechanism consistent with kinetic results has been proposed in which a combined role of Mn(III)aq and MnOH2+aq was envisaged.
  • K. R. Sabu, K. V. C. Rao, C. G. R. Nair
    1990 Volume 63 Issue 12 Pages 3632-3634
    Published: 1990
    Released: June 05, 2006
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    The acidity evaluations using butylamine titration have been carried out to correlate the surface acidic properties of TiO2–SiO2–Al2O3 catalysts with their alkylating activity. The acid amount of TiO2–SiO2–Al2O3 of silica to alumina molar ratio 16.4 and titania content 10.4% (by weight) is nearly double that of SiO2–Al2O3 of the same silica to alumina molar ratio. The acid strength of TiO2–SiO2–Al2O3 coprecipitated from a solution of pH 2 and the acid amount of the same ternary oxide coprecipitated from solutions of higher pH(>6) are low.
  • K. N. Mehrotra, M. K. Rawat
    1990 Volume 63 Issue 12 Pages 3635-3639
    Published: 1990
    Released: June 05, 2006
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    The specific conductance of manganese(II) decanoate in DMF and 1-butanol was measured with a view to determine the critical micelle concentration (CMC), degree of dissociation, and dissociation constant. It was found that the soap behaves as a simple electrolyte and is ionic in nature. The CMC was found to be independent of the dielectric constant of the solvent. The ionic character of manganese(II) decanoate was also confirmed by spectrophotometric measurements.
  • Monila Seth, Abha Mathur, Kalyan K. Banerji
    1990 Volume 63 Issue 12 Pages 3640-3643
    Published: 1990
    Released: June 05, 2006
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    Oxidation of the lower oxyacids of phosphorus by pyridinium chlorochromate (PCC) results in the formation of the corresponding higher oxyacids of phosphorus. The reaction is of first order with respect to PCC and the oxyacid. The reaction is catalyzed by hydrogen ions, kobs=a+b[H+]. The reaction exhibited a substantial primary kinetic isotope effect. The rates in 19 different organic solvents have been analyzed using Kamlet–Taft’s and Swain’s equations. It has been found that the cation-solvating power of the solvents plays a predominant role. It is proposed that the “inactive” tautomer of the phosphorus oxyacids is the reactive species. Transfer of a hydride ion from the P–H bond to PCC, in the rate-determining step, has been proposed.
  • C. S. T. Sai, N. R. Anipindi, V. Subbiah, M. W. Pandit
    1990 Volume 63 Issue 12 Pages 3644-3646
    Published: 1990
    Released: June 05, 2006
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    A study has been made of the acid-catalysed aquation reactions of three complex ions of the general formula [Cr(XX)2(CO3)]3−, where XX=oxalate, malonate, or methylmalonate, by stopped-flow spectrophotometry in the acid range 0.1–2.0 M (M=mol dm−3) and 20–35°C at an ionic strength of 2 M. Only the ring-opening reaction of the carbonate is observed, k=2.12, 3.28, and 4.02 M−1 s−1 at 25°C respectively for oxalato, malonato, and methylmalonato complexes as the subsequent decarboxylation is too fast to measure. The observed trend was explained in terms of the basicity of the coordinated inert ligands.
  • Dhruv Kumar Singh, Pallavi Mehrotra
    1990 Volume 63 Issue 12 Pages 3647-3652
    Published: 1990
    Released: June 05, 2006
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    A new inorganic ion exchanger, anilinium zirconium(IV) phosphate (AZP), has been prepared under varying conditions. The effects of mixing ratio of reagents and the pH of the mixture on the ion-exchange properties of the material have been studied. The detailed studies, such as ion-exchange capacity, chemical and thermal stabilities, chemical composition, pH titration, and IR analysis were made. Distribution coefficients of metal ions have been studied in water, nitric acid, 1,4-dioxane, aqueous ammonium nitrate, thiourea–nitric acid, and thiourea–hydrochloric acid media. Some analytically important separations of metal ions have been achieved on the small columns of AZP.
  • M. I. Ismail
    1990 Volume 63 Issue 12 Pages 3653-3657
    Published: 1990
    Released: June 05, 2006
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    The reduction of hexavalent uranium in 1 M H2SO4 at DME was found to be retarded by a non ionic surfactant Triton® X 100 and to shift the uranium wave to more negative potentials. Advantage was taken of this fact to determine the elements Hg(II), Fe(III), V(V), As(III), Sb(III), and Ti(IV) either individually in the presence of U(VI) or simultaneously in mixtures, a supporting electrolyte of 1 M H2SO4 containing 0.01% Triton® X 100 was used. The i1/C results gave excellent correlations in each case, as was indicated from the least squares regression analysis. The outcome results suggest the method validity as a quantitative method for determination of the studied elements.
  • Mrinal K. Das, Purnendu Mukherjee, Sarbari Roy
    1990 Volume 63 Issue 12 Pages 3658-3660
    Published: 1990
    Released: June 05, 2006
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    Syntheses of a number of amine-methoxycarbonylboranes R2−nHnN·BH2COOCH3 and trimethylamine-(alkylcarbamoyl)boranes, Me3N·BH2CONRR′ are reported. Both types of compounds have been prepared by condensing appropriate amine-carboxyboranes with methanol and an amine, respectively, in presence of dicyclohexylcarbodiimide, and have bean characterized by elemental analysis, IR and NMR (1H and 11B) spectra.
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