Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
Volume 52 , Issue 8
Showing 1-50 articles out of 66 articles from the selected issue
  • Katsuyoshi Kamakura
    1979 Volume 52 Issue 8 Pages 2175-2177
    Published: 1979
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    When a two-layer system which consists of water (upper layer) and an aqueous solution (lower layer) is heated from one side and cooled from the opposite side, a convection starts in each layer and a sharp horizontal boundary is formed by the two flows in opposite directions. The empirical formula for the transfer of a solute across the boundary was obtained by measuring the change in the concentration of a solute in the upper layer. The flux, WA, of a solute, A, was expressed by
    WA=a3(Δρ1Δρ0)D0.5(ΔcIΔρ2).
    Here, a3 is the mass-transfer coefficient; Δρ1, the density difference between the liquid on the heated wall and that on the cooled wall; Δρ0, the value of Δρ1 at which the convections start; D, the diffusion coefficient of a solute; and ΔcI and Δρ2, the concentration difference and the density difference, respectively, between the solution of the upper layer and that of the lower layer.
  • Keiichi Ohno, Akitoshi Mitsui, Hiromu Murata
    1979 Volume 52 Issue 8 Pages 2178-2183
    Published: 1979
    Released: April 19, 2006
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    The infrared and Raman spectra of isopropyl methyl selenide and diisopropyl selenide were measured for the liquid and solid states. The fundamental vibrations were assigned and the rotational isomerism was studied on the basis of the spectral observations and the normal coordinate treatment. For isopropyl methyl selenide, the C1 and Cs forms coexisted in the liquid state and the enthalpy difference between them was obtained as ΔH(C2Cs)=−0.52×0.05 kcal mol−1. For diisopropyl selenide, it was presumed that only the C2 form persisted in the solid state while the C2, Cs, and C1 forms coexisted in the liquid state, the C2 form being the most stable.
  • Kimiko Mizutani, Yoshihiro Kuribara, Kazuko Hayashi, Shiro Matsumoto
    1979 Volume 52 Issue 8 Pages 2184-2188
    Published: 1979
    Released: April 19, 2006
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    Potential energy surfaces were computed for the Li–H2 system of C2V symmetry, which dissociates to a normal hydrogen molecule and a lithium atom either in its ground state or in the 2P excited state, in order to get an idea of the quenching process of the atom by the molecule. The potential surfaces crossed in a line and two shallow minima appeared on the 2B2 surface. Natural orbital analysis and electron density maps gave information on the charge transfer character of the interaction of the excited atom with the molecule.
  • Yuzo Imizu, Hideshi Hattori, Kozo Tanabe, Toshihiko Kondo
    1979 Volume 52 Issue 8 Pages 2189-2191
    Published: 1979
    Released: April 19, 2006
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    Mechanistic study on the isomerization of cyclopropane into propene was made over Th(SO4)2 catalyst. With a fresh catalyst, an induction period was observed, disappearing in successive runs. Coisomerization of cyclopropane d0/d6 reveals that the reaction involves an intermolecular H(or D) transfer. Nearly random location of the H(or D) atom in the mono-exchanged propene-d1, and -d5 indicates that the isomerization proceeds via nonclassical carbonium ion in which seven hydrogen atoms are equivalent.
  • Yumiko Sano, Yasuhiko Shirota, Hiroshi Mikawa
    1979 Volume 52 Issue 8 Pages 2192-2194
    Published: 1979
    Released: April 19, 2006
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    Studies have been made of the singlet excitation energy migration of 1,3-diphenyl-5-(p-chlorophenyl)-2-pyrazoline in a glassy state blended with an ethylene-vinyl acetate copolymer by the fluorescence quenching method. The results are discussed in terms of the simple random energy migration model, showing that the efficiency of the singlet excitation energy migration does not differ between the glassy state and the polymer blend system.
  • Hitofumi Taniguchi, Tatsuo Masuda, Kazuo Tsutsumi, Hiroshi Takahashi
    1979 Volume 52 Issue 8 Pages 2195-2198
    Published: 1979
    Released: April 19, 2006
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    Heats of adsorption of gaseous triphenylchloromethane (TPC) onto silica–alumina surface were determined from the heat evolved with the immersion of silica–alumina into TPC–hexane solution. The heat of dissolution and the heat of sublimation of TPC and the heat of immersion of the sample into hexane were considered for their determination. It became clear that TPC molecules interacted with silica–alumina surface in two manners. The one was observed in smaller adsorbed amount (below 45 μmol/g), and the other in adsorbed amount from 45 to 100 μmol/g. The former could be attributed to the interaction between TPC and Lewis or oxidizing sites and the latter to the attractive interaction between the adsorbed molecules. The adsorbed amount in the first stage (4.7×1012 molecules/cm2) agreed closely with the number of Lewis acid sites (5.0×1012 sites/cm2) measured by Leftin and Hall.
  • Masatsugu Kajitani, Akira Sugimori, Naoki Sato, Kazuhiko Seki, Hiroo I ...
    1979 Volume 52 Issue 8 Pages 2199-2201
    Published: 1979
    Released: April 19, 2006
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    The He I spectra of 12-crown-4, 15-crown-5, 18-crown-6, dicyclohexyl-18-crown-6, and dibenzo-18-crown-6 have been measured. The features of the spectra are similar except for the case of dibenzo-18-crown-6, where two lower IP bands correlated with the highest occupied π-orbitals of benzene are observed together with the bands due to the polyether ring. By the aid of the CNDO/2 calculation, the lower IP bands of the spectra have been assigned to the MO’s mainly due to the equatorial or axial type non-bonding orbitals of the oxygen atoms of the polyether rings.
  • Jun-ichi Aihara
    1979 Volume 52 Issue 8 Pages 2202-2204
    Published: 1979
    Released: April 19, 2006
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    An ideal multi-center bond is a bond in which three or more atomic orbitals of the same kind, each from a different atom, interact equally with each other. Since such a multi-center bond can be regarded as a cyclic conjugated system, the graph theory of aromaticity can be applied to it. It was then found that multi-center bonds are aromatically stabilized to a great extent. Most inorganic cluster compounds are polyhedral in shape. This might be rationalized by the fact that polyhedrons are favorable to a formation of a multi-center bond or the like at the core.
  • Kan Kanamori, Masamitsu Mihara, Kiyoyasu Kawai
    1979 Volume 52 Issue 8 Pages 2205-2208
    Published: 1979
    Released: April 19, 2006
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    Laser Raman spectra of aqueous solutions of lithium, potassium, and caesium oxalates have been obtained; their band contours were examined by curve analysis. The intensities of several bands show distinct concentration and cation dependences. This behavior is connected with the ion-pair formation of oxalate ions with alkali metal cations. The assignments of C=O stretching vibrations are also discussed.
  • Masaaki Sugiura, Toshio Shinbo
    1979 Volume 52 Issue 8 Pages 2209-2213
    Published: 1979
    Released: April 19, 2006
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    The uphill transport of metal ions such as copper, zinc, cobalt, and iron(II) ions through a bulk 1,2-dichloroethane membrane in the presence of various chelating agents has been studied. The membrane separated two aqueous phases, one containing the metal ion and potassium or lithium sulfate, and the other containing the metal ion and lithium nitrate or chloride. The chelating agents used were derivatives of 1,10-phenanthroline and acetylacetone. The accumulation of the metal ions in the aqueous phase containing the potassium or lithium sulfate was observed for only the following chelating agents: copper: 4,7-diphenyl-2,9-dimethyl- and 4,7-diphenyl-1,10-phenanthroline; zinc: 4,7-diphenyl-, 3,8-diphenyl-, 2,9-dimethyl-, and 4,7-diphenyl-2,9-dimethyl-1,10-phenanthroline; cobalt: 3,8-diphenyl- and 4,7-diphenyl-1,10-phenanthroline; and iron(II): 3,8-diphenyl-1,10-phenanthroline. In the system containing lithium sulfate in the aqueous phase, the rate of transport of the metal ions was slightly higher than that in the system containing potassium sulfate. The reduction of the nitrate ion in the aqueous phase brought about a lowering of the rate of transport of the metal ions. The transport of the metal ions was, however, unaffected by the electrostatic effect. The metal ion complexed by the chelating agent may be transferred in the 1,2-dichloroethane phase, thus forming an ion-pair with the nitrate or chloride ion.
  • Yukako Ohashi, Takayoshi Kobayashi
    1979 Volume 52 Issue 8 Pages 2214-2217
    Published: 1979
    Released: April 19, 2006
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    In order to study the solvent effect on the lowest excited state of of cis-[IrCl2L2]Cl (L=2,2′-bipyridine, 1,10-phenanthroline, and 4,7-dimethyl-1,10-phenanthroline), the triplet-triplet absorption spectra (15000 cm−1—27000 cm−1) were measured by the use of N,N-dimethylformamide–water mixed solvents. For the triplet-triplet spectra of the three iridium complexes, remarkable spectral changes were observed with the change of the solvent polarity. An SCF calculation of the triplet-triplet transitions was carried out for free bipyridine and free phenanthroline. By comparing the calculated results and the observed spectra, the solvent effect can be interpreted in terms of a model invoking dπ*-ππ* interaction, as proposed by Crosby. The lowest triplet state of [IrCl2(phen)2]Cl is predominantly a dπ* state in 95% v/v DMF–water, but in water, by the reversal of the state ordering, the lowest state becomes a ππ* state. Furthermore, a quite similar solvent effect which was observed on the lowest triplet state of [IrCl2(bpy)2]Cl is discussed; this state is not expected to have a dπ*-ππ* interaction.
  • Akira Itaya, Ken-ichi Okamoto, Shigekazu Kusabayashi
    1979 Volume 52 Issue 8 Pages 2218-2222
    Published: 1979
    Released: April 19, 2006
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    The photo-oxidation effect on poly(N-vinylcarbazole) (PVCz) and amorphous 1,3-di(N-carbazolyl)propane films was studied by means of ultraviolet absorption, infrared absorption, and fluorescence spectra. The photoconductivity of the photo-oxidized PVCz films was also measured as a function of photoirradiation time. A photo-oxidation product which formed near the surface of films had a carbonyl substituent group, acted as a singlet exciton trap in competition with the excimer-forming sites, and formed an exciplex with an excited carbazolyl chromophore. The very slight amount of the photo-oxidation product enhanced the photoconductivity of PVCz films by a factor of ca.15, suggesting that the product acted as an electron-accepting impurity in the photo-carriergeneration mechanism in the lowest π-π* absorption region of PVCz films.
  • Yasuhide Fukutani, Kumiko Tsukihara, Yukio Okuda, Keiichi Fukuyama, Yu ...
    1979 Volume 52 Issue 8 Pages 2223-2228
    Published: 1979
    Released: April 19, 2006
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    X-Ray diffraction analysis was used to establish the molecular structures of some adducts of benzoyl isothiocyanate with hydrazones: benzaldehyde 4-benzoyl-2-phenylthiosemicarbazone (1), 2-benzoylimino-3,5-diphenyl-2,3-dihydro-1,3,4-thiadiazole (2), and 5-benzoylimino-2,2-dimethyl-4-phenyl-1,3,4-thiadiazolidine (3). In adducts 2 and 3, a strong intramolecular interaction between sulfur and carbonyl oxygen atoms has been found. The S…O distance is 2.56 Å for 2 and 2.76 Å for 3, and the oxygen atom lies approximately in the plane defined by the sulfur atom and the two carbon atoms bonded to the sulfur atom. The absence of a characteristic absorption due to a carbonyl group in the IR spectra of 2 and 3 reflects the intramolecular interaction. The crystal of 1 is triclinic, space group P\barl, with a=12.041, b=8.414, c=11.298 Å, α=116.13, β=103.39, γ=103.27°; that of 2 is monoclinic, space group P21/c, with a=20.842, b=3.977, c=21.120 Å, β=103.55°; and that of 3 is monoclinic, space group P21 with a=12.559, b=6.910, c=10.283 Å, β=115.46°. The structure has been refined by the block-diagonal least-squares method to R=0.089 with 2508 reflections for 1, to R=0.088 with 1872 reflections for 2, and to R=0.098 with 1031 reflections for 3.
  • Taizo Ono, Hirotaka Shimanouchi, Yoshio Sasada, Takeshi Sakurai, Osamu ...
    1979 Volume 52 Issue 8 Pages 2229-2234
    Published: 1979
    Released: April 19, 2006
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    Two copper complexes containing L-histidine and L-asparagine crystallize from aqueous solution at pH 7.0. Both crystals are monoclinic, space group P21. L-Asparaginato-L-histidinatocopper(II): a=10.913(3), b=12.911(4), c=10.206(3) Å, β=113.83(2)°, Z=4. L-Asparaginato-L-histidinatoaquacopper(II) trihydrate: a=12.654(4), b=11.623(4), c=5.931(2) Å, β=100.47(3)°, Z=2. In both structures, four coordinating atoms in an approximately planar arrangement around copper are the α-amino and imidazole δ-nitrogen atoms of L-histidine and α-amino nitrogen and α-carboxyl oxygen of L-asparagine. The fifth coordination site is occupied by the α-carboxyl oxygen of L-histidine. Difference between the two complex crystals is found at the sixth coordination site; a water molecule is coordinated in the hydrated crystal to complete a distorted octahedral environment, while in the anhydrous crystal this site is unoccupied so that the geometry of the complex is square-pyramidal.
  • Tsunetake Fujiyama, Haruo Hatakeyama, Shi-aki Hyodo
    1979 Volume 52 Issue 8 Pages 2235-2239
    Published: 1979
    Released: April 19, 2006
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    Raman intensities of methyl iodide were observed in carbon tetrachloride solution at various concentrations. The observed lines were ν1, ν2, ν3, ν5, and ν6. From the observed data, the transition polarizabilities were determined for the ν1, ν2 and ν3 fundamentals of methyl iodide and the transition hyperpolarizabilities were obtained for the ν3 fundamental of methyl iodide in the form of tensor elements.
  • Isao Ando, M. Jallali-Heravi, Masahiro Kondo, Shosuke Watanabe, G. A. ...
    1979 Volume 52 Issue 8 Pages 2240-2243
    Published: 1979
    Released: April 19, 2006
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    Nitrogen screening constants are calculated by the sum-over-states method using INDO/S parameters and by the finite perturbation procedure employing INDO parameters. The solvaton model is employed to describe changes in nuclear screening as a function of the dielectric constant of the medium. The calculated variations of nitrogen screening are in reasonable agreement with the available experimental data. The effects on screening of hydrogen bonding are included in the sum-over-states calculations by means of dimer models.
  • Yukio Matsuoka, Kiwamu Yamaoka
    1979 Volume 52 Issue 8 Pages 2244-2249
    Published: 1979
    Released: April 19, 2006
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    The linear dichroic absorption spectra of Pararosaniline (PR), Crystal Violet (CV), and Ethyl Violet (EV) were measured in the UV and visible regions by the stretched film technique. Poly(vinyl alcohol) was used as the film matrix. A method, which is expressed in the forms of reduced dichroism and dichroic ratio, was proposed for the analysis of the linear dichroism of disk-like molecules. The dyes PR, CV, and EV were shown to behave like disks regarding their orientation in the polymer matrix. The isotropic absorption spectra of PR, CV, and EV were resolved into the in-plane and out-of-plane polarized components by the reduction procedure. In each isotropic spectrum the out-of-plane component was found to overlap with the intense in-plane component in the UV and visible wavelength regions.
  • Satoshi Morimoto
    1979 Volume 52 Issue 8 Pages 2250-2254
    Published: 1979
    Released: April 19, 2006
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    Determination of the thermodynamic quantities of the self-association of 6-methylpurine in water(1)–1,4-dioxane(2) (x2=0–0.36) mixed solvent has been made from heat of dilution measurements in various organic contents, at 25 °C. It was confirmed experimentally that the dissociation process of associating purine bases in solution is very fast by dilution. It was characteristic of this solvent system that the standard enthalpy and entropy changes, ΔH° and ΔS°, of the association exhibited an abrupt behavior. These values decrease remarkably with 1,4-dioxane content up to a water-rich solvent composition below x2=0.012. After that, they approach their relatively high values for the pure organic component, at first with a steep slope, later more gradually. This behavior is related to the structural changes of the solvent in an extremely sensitive way. In the case of water (1)–methanol(2) (x2<0.19) mixed solvent system which has been investigated for comparison with the above system, minimum values of the same kind were found in the vicinity of x2=0.12, at 25 °C.
  • Shun-ichi Fukuzumi, Yoshio Ono
    1979 Volume 52 Issue 8 Pages 2255-2260
    Published: 1979
    Released: April 19, 2006
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    The decomposition of 1-methyl-1-phenylethyl hydroperoxide and t-butyl hydroperoxide with Mn(II)(acac)2 and the autoxidation of cumene with Mn(II)(acac)2, Mn(III)(acac)3, and MnCO3 have been studied at 323 K. In the decomposition of the hydroperoxides with Mn(II)(acac)2, the peroxyl radicals are observed only when the initial ratio of hydroperoxide to catalyst amount exceeds a certain value. The critical phenomenon is observed in the oxidation of cumene with Mn(II)(acac)2 and also with MnCO3. A scheme for the cause of the critical phenomena has been proposed.
  • Akira Fuyuhiro, Kazuaki Yamanari, Yoichi Shimura
    1979 Volume 52 Issue 8 Pages 2261-2263
    Published: 1979
    Released: April 19, 2006
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    Four-component solubility isotherm of reciprocal salt-pairs consisting of (Λ-[Co(ox)(en)2]+, Δ-[Co(ox)(en)2]+)–(Cl, d-C10H14OBrSO3)–H2O has been determined experimentally at 25 °C. It was found that a pseudoracemate, Λ-[Co(ox)(en)2Δ-[Co(ox)(en)2](d-C10H14OBrSO3)2·2H2O, is present as the only double salt, optical resolution of the bis(ethylenediamine)oxalatocobalt(III) ion in this system at 25 °C being impossible as in the case of the ternary system, Λ-[Co(ox)(en)2](d-C10H14OBrSO3)–Δ-[Co(ox)(en)2](d-C10H14OBrSO3)–H2O, at 25 °C.
  • Susumu Kohata, Noriko Itoh, Hitoshi Kawaguchi, Akira Ohyoshi
    1979 Volume 52 Issue 8 Pages 2264-2267
    Published: 1979
    Released: April 19, 2006
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    The thermochemical reactions of [Ru(NH3)5N2]X2 (X=Cl, Br, I) were investigated in the solid state. The ammonia ligand was liberated at a lower temperature (165–213 °C) than the nitrogen ligand (243–270 °C). The isothermal measurement reveals that the first step of the degradation of the complex can be expressed as: [Ru(NH3)5N2]X2(s)→[RuX(NH3)4N2]X(s)+NH3(g) (X=Cl, Br, or I). The rate of the reaction is first-order to [Ru(NH3)5N2]X2, and the first-order rate constant increased in the order of: chloride<bromide<lodide. The activation energies and the activation entropies (E/kJ mol−1 and ΔS\ eweq/J K−1 mol−1 respectively) for the reaction were as follows: chloride (181±1,62±1), bromide (99±1, −95±2), and iodide (89±1, −102±3). The values of ΔS\ eweq suggest that the salt with Cl degrades through an SNl-like mechanism, while those with Br and I degrade through an SN2-type mechanism. The thermochemistry of [Ru(NH3)5N2]X2 has been discussed on the basis of the strong π-backbonding ability of the nitrogen ligand and the electronegativity of the outer-sphere ions.
  • Tetsuhiko Yoshimura, Tomio Ozaki
    1979 Volume 52 Issue 8 Pages 2268-2275
    Published: 1979
    Released: April 19, 2006
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    The equilibria of sterically hindered and unhindered imidazoles (B) with (protoporphyrin IX dimethyl ester)iron(III) chloride (Fe(PPDME)Cl) have been spectrophotometrically investigated in chloroform and 1,2-dichloroethane. The addition reaction of hindered imidazole with Fe(PPDME)Cl proceeds in two steps to give Fe(PPDME)B2Cl, with a formation constant, K1, greater than K2. The mono-adduct of hindered imidazoles exhibits an absorption band at around 590 nm, which shifts to longer wavelengths as the formation constant K1 decreases in this order; 2,4-dimethyl->2-methyl->2-ethyl->2-phenyl->1,2-dimethylimidazole. The addition reaction of an unhindered imidazole with Fe(PPDME)Cl proceeds in an apparent one step to give Fe(PPDME)B2Cl, with an overall formation constant of β2. The logβ2 linearly increases with the basicity, pKa(BH+), of unhindered imidazoles. The logβ2 for the system with NH-containing imidazoles is greater than that for the system with N-substituted imidazoles by about 3.1 log units, on the average, based on the stabilization of the positive charge on iron(III) through NH…Cl hydrogen bonding. The solvent effect on the formation constants is also discussed.
  • Kazuo Jin, Mitsuhiko Taga, Hitoshi Yoshida, Seiichiro Hikime
    1979 Volume 52 Issue 8 Pages 2276-2280
    Published: 1979
    Released: April 19, 2006
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    Sensitive determination of tellurium was investigated by atomic absorption spectrophotometry after hydride generation and differential determination of tellurium(IV) and tellurium(VI) in acidic solution was carried out. When sodium borohydride solution is used without any prereductant, only the signal from tellurium(IV) is obtained. On the other hand, when titanium(III) chloride solution is added before the addition of borohydride solution, total signal from tellurium(IV) and tellurium(VI) can be obtained; 30—60 s of prereduction is required. The effectiveness of the titanium(III) chloride-borohydride reduction system is shown in the interference study. The interference of selenium(IV) is eliminated up to 200 fold vs. 0.25 μg of tellurium(IV) in 20 cm3 of 3 mol dm−3 hydrochloric acid by the use of 2 cm3 of 5% w/v titanium(III) chloride solution as a prereductant. Tellurium in steel and sulfur (commercial reagent) can be determined satisfactorily without isolation of tellurium from matrix by this method. Detection limit of the method is 8 ng. The coefficient of variation of the method is 2.4% in the ten determinations of 0.25 μg of tellurium.
  • Koji Takeuchi, Tomihito Kambara
    1979 Volume 52 Issue 8 Pages 2281-2286
    Published: 1979
    Released: April 19, 2006
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    It was shown that the shape of gas-liquid chromatographic peak is expressed by the Gaussian distribution multiplied by a higher order algebraic equation of time. Application of the curve fitting methods, i.e., the Newton’s divided-difference formula and the orthogonal polynomials method, could well clear up the experimentally observed gas-liquid chromatograms of trailing and leading types, respectively. The asymmetric shapes of gas-liquid chromatographic peaks are attributed to the slowness of vaporization or dissolution in the partition process.
  • Takashi Yasuoka, Shunmei Mitsuzawa
    1979 Volume 52 Issue 8 Pages 2287-2289
    Published: 1979
    Released: April 19, 2006
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    A new technique using a solid substance for the absorption of nitrogen oxides in the atmosphere was developed in order to obtain an average concentration of nitrogen oxides over a period of several weeks. Nitrogen oxides is absorbed by an absorbent (alkaline earth metal peroxide), and the nitrate produced in the absorber is extracted into water to determine the amount of nitrate by the ion-selective electrode method. The concentration of atmospheric nitrogen oxides is calculated from the amount of nitrate in the extract. A quantitative relation was found between the amount of nitrogen oxides collected on the absorber and that of nitrate in the extract. Hydrogen peroxide produced by the reaction of the absorber and water did not interfere with the measurement of nitrate by the ion-selective electrode technique. Practicability of this technique was demonstrated in comparison with the automatic recording analyzer (NOx meter) with the Saltzman reagent.
  • Masayasu Iida, Hideo Yamatera
    1979 Volume 52 Issue 8 Pages 2290-2294
    Published: 1979
    Released: April 19, 2006
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    The aquation of the bromopentacyanocobaltate(III) ion was carried out in the presence of several kinds of hard acids or halomercury(II) complexes. The hard acids(H+, Na+, and Mg2+) had small effects, while the addition of mercury(II) halides significantly accelerated the aquation. The effect of mercury(II) halides was attributed to the monohalomercury(II) cations, which were formed in a small amount by the dissociation of the dihalomercury(II) complexes. The effect of the dihalomercury(II) complexes was also studied in the presence of an excess of sodium halide. The rate constant for halomercury(II)-assisted aquation was expressed by:
    kobsd=k0+k1[HgX+]+k2[HgX2], X=Cl,Br.
    The values of k1 and k2 obtained (k1=1.6×104 mol−1 dm3 s−1, k2=1.0 mol−1 dm3 s−1, for X=Cl; k1=2.0×104 mol−1 dm3 s−1, k2=1.6×10−1 mol−1 dm3 s−1, for X=Br) were compared with the stability constants for the mercury(II) complexes formed by the combination with Br.
  • Yoshihiro Sasaki, Matsujiro Sakurada, Masakazu Matsui, Tsunenobu Shige ...
    1979 Volume 52 Issue 8 Pages 2295-2298
    Published: 1979
    Released: April 19, 2006
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    Formation constants and thermodynamic parameters for the 1: 1 adduct-formation reactions of bis(trifluoroacetylacetonato)copper(II), Cu(tfac)2, with alkylamines, α-picoline, 2,6-lutidine, and THF have been determined spectrophotometrically. The ΔH°–ΔS° plots for primary and secondary alkylamines gave a linear relationship for the thermodynamic parameters of the Cu(tfac)2-heterocyclic base systems. The plots for the 2,6-lutidine, THF and tertiary alkylamine systems have been found consistent with a correlation between ΔH° and ΔS° values for bis(acetylacetonato)copper(II)–heterocyclic base systems. It has been subsequently deduced that the 1: 1 adducts of Cu(tfac)2 with Lewis bases possess a square-pyramidal structure on the basis of the ESR data for the 63Cu(tfac)2–Lewis base systems.
  • Hitoshi Kanno
    1979 Volume 52 Issue 8 Pages 2299-2302
    Published: 1979
    Released: April 19, 2006
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    As an extension of the atomic/molecular vaporization model, a new method is presented for correcting the isotopic fractionation effects in the multiple filament thermal ionization source (MFTIS). It is applicable to the isotope ratio measurements of the element having only two observable isotopes.
  • Yuh’ichi Rokugawa, Masao Sugawara, Tomihito Kambara
    1979 Volume 52 Issue 8 Pages 2303-2306
    Published: 1979
    Released: April 19, 2006
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    A sensitive extraction-spectrophotometrie method for determination of cobalt(II) with Eriochrome Black T is described, which involves the preliminary separation of cobalt from aqueous solution by the benzene extraction of methyltrioctylammonium tetrathiocyanatocobaltate(II). The quantitative formation of ion pair between cobalt–Eriochrome Black T complex anion and the quaternary ammonium cation is attained by shaking the resulting extract with aqueous Eriochrome Black T solution of pH 5.5–8.2. Beer’s law holds for 0.57–4.0 μg cobalt in 5 ml of the extract with the molar absorption coefficient of ε587=6.62×104 cm−1 mol−1l (Sandell sensitivity 8.90×10−4 μg cm−2). The composition of the extracted ion pair is estimated to be cobalt: Eriochrome Black T:methlytrioctylammonium ion=1:2:3.
  • Toshio Yao, Soichiro Musha
    1979 Volume 52 Issue 8 Pages 2307-2311
    Published: 1979
    Released: April 19, 2006
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    The electrochemical oxidation of aminopurines and their hydroxy derivatives, which gave a single voltammetric peak at the glassy carbon electrode, was investigated by means of linear-sweep voltammetry, cyclic voltammetry, coulometry, and macroscale control!ed-potential electrolysis. In general, the ease of oxidation of these compounds increased in proportion to the number of hydroxyl or amino groups on the molecule. The coulometric n-values for monosubstituted purines were 5.86–6.08, for disubstituted purines they were 3.90–4.20, and for trisubstituted purines they were 2.07–2.33. The electrochemical oxidation of the different aminopurines appeared to follow initially the same path as the enzymatic oxidation; i.e., the primary attack for the electrochemical oxidation occurred first at the C-8 position, and then the C-2 position. Thus, aminopurines were oxidized in two sequential two-electron processes to give first 8-hydroxy and then 2,8-dihydroxy(or 6,8-dihydroxy) intermediates. Then, this latter intermediate was further oxidized in a two-electron process to produce a diimine intermediate, which was unstable and which then broke down to the ultimate products, such as parabanic acid, oxaluric acid, urea, ammonia, allantoin, and guanidine.
  • Toshiaki Mitsugashira, Hajimu Yamana, Shin Suzuki
    1979 Volume 52 Issue 8 Pages 2312-2319
    Published: 1979
    Released: April 19, 2006
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    A method for the isolation of 227Ac and its daughter nuclides from 231Pa was established. The γ-ray spectra of 231Pa, 227Th, and 223Fr were investigated, and the γ-ray tables of these nuclides were presented. A decay scheme of 223Fr was corrected so as to explain these γ-ray data.
  • Reiko Saito, Yoshinori Kidani
    1979 Volume 52 Issue 8 Pages 2320-2322
    Published: 1979
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    The thermal transformations of the following three types of nickel(II) complexes were investigated by means of TG-DSC analyses: [Ni(t-chxn)2(H2O)2]X2, [Ni(c-chxn)3]X2·nH2O, and [Ni(t-chxn)3]X2·nH2O (X=Cl, Br, and NO3), where c- and t-chxn denote cis- and trans-1,2-cyclohexanediamine respectively. The distorted octahedral [Ni(t-chxn)2(H2O)2]X2 complexes (X=Cl and Br) are thermally deaquated to form yellow complexes, which then turn into parental diaquabis-complexes in the air at room temperature. [Ni(t-chxn)2(H2O)2] (NO3)2 undergoes a thermal deaquation-anation reaction. The octahedral tris(c-chxn) complex is converted into a square planar bis(c-chxn) one by the evolution of one molecule of the ligand upon heating, whereas tris(t-chxn) complex became a distorted octahedral bis(t-chxn) one with anion coordination. In this paper, the stereochemical thermal changes of the complexes in the solid state will be discussed with regard to the steric configuration of the ligands.
  • Mitsutomo Tsuhako, Chinuyo Oyama, Tsuneo Matsuo, Itaru Motooka, Masami ...
    1979 Volume 52 Issue 8 Pages 2323-2328
    Published: 1979
    Released: April 19, 2006
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    The conditions of formation of the A and B forms of Fe(H2PO4)3 by the reaction of Fe2O3 and H3PO4 have been established, and the thermal changes and structural changes in humid atmospheres investigated. 1) The A and B forms of Fe(H2PO4)3 were readily formed by secondary heat treatment at 150 °C and 125 °C, respectively. 2) The forms of Fe(H2PO4)3 were largely dependent on the heating rate in the primary heat treatment, i.e., at a mean heating rate less than 7 °C/min the A form predominated, whereas above 60 °C/min the B form predominated. A heating rate between 7 and 60 °C/min gave a mixture of the A and B forms. 3) A close relationship between the water content of the primary product and yields of the A and B forms of Fe(H2PO4)3 was found, i.e., only the B form was obtained when the water content of the primary product was less than 7%, while the A form was readily formed when the water content was greater than 11%. 4) Heating the primary product under various degrees of humidity enabled the formation of Fe(H2PO4)3 to be investigated. The effect of heating atmosphere was small except under vacuum. 5) The structural changes of the A and B forms of Fe(H2PO4)3 under several humid atmospheres are summarized as follows:
    (Remark: Graphics omitted.)
  • Yasuhiko Kondo, Akira Nishikata, Akiteru Yoshioka, Niichiro Tokura
    1979 Volume 52 Issue 8 Pages 2329-2333
    Published: 1979
    Released: April 19, 2006
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    The Finkelstein reaction has been studied in five dipolar aprotic–dipolar aprotic solvent mixtures and one protic-dipolar aprotic solvent mixture. The theoretical equations for the rate constant as a function of solvent composition derived previously have been reformulated in terms of the solvent exchange model on the solvation site, taking into account the two main features of solvation: the number of the solvation sites on the solvent molecule and the equilibrium constant for the solvent exchange process. The results obtained previously, together with present results, are comprehensively discussed and the solvent mixtures are classified into four groups from the viewpoint of solute-solvent interaction in the region near the ion, using derived theoretical equations.
  • Keizo Ogawa, Akiko Nomura, Takaji Fujiwara, Ken-ichi Tomita
    1979 Volume 52 Issue 8 Pages 2334-2338
    Published: 1979
    Released: April 19, 2006
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    The crystal structure of mitomycin C was determined by means of X-ray diffraction. Mitomycin C was crystallized in the orthorhombic space group P212121, with a=12.887, b=13.851, c=9.718 Å, and Z=4, and its structure solved by the trial and error method using the rigid-body approximation. The absolute configuration was determined by referring to that of N-(p-bromobenzoyl) mitomycin C. The carbamoyloxymethyl side chain participates in hydrogen bonds as in the case of other mitomycins in the crystalline state.
  • Mariko Kamimori, Hirochika Sakuragi, Katsuhiko Sawatari, Tadashi Suehi ...
    1979 Volume 52 Issue 8 Pages 2339-2342
    Published: 1979
    Released: April 19, 2006
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    N-Benzylidene-t-butylamine oxide (PBN), N-benzylideneaniline oxide (DPN), and 2,3,5,6-tetraraethylnitrosobenzene (ND) trap phenyl radicals in a relative rate of 1 : 0.72 : 2.6, whereas they trap phenylcyclohexadienyl radicals in a relative rate of 1 : 2.3 : 130. The origin of such different spin-trapping abilities of these spin traps towards phenylcyclohexadienyl radicals is discussed.
  • Masatsugu Kajitani, Naoki Suzuki, Tsutomu Abe, Yoshimitsu Kaneko, Kazu ...
    1979 Volume 52 Issue 8 Pages 2343-2348
    Published: 1979
    Released: April 19, 2006
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    The difference in the nature of nickel and cobalt catalysts has been investigated by a comparative study of the competitive hydrogenation of substituted acetophenones. The electronic and steric effects of substituents and the effects of solvents on the adsorption strength of acetophenones are greater for the reactions over R-Ni than for those over R-Co. On R-Co catalyst acetophenones substituted with electron attracting groups (3-methoxyl, 3-hydroxyl, and 4-fluoro groups with σ0>0) are adsorbed more strongly than those with electron donating groups (2-, 3-, and 4-alkyl and 4-methoxyl groups with σ0<0). Over R-Ni catalyst the adsorption of acetophenone is greater than that of any substituted acetophenones. The rates of hydrogenation over R-Ni are more susceptible to the effects of substituent and solvent than those over R-Co. Over both R-Ni and R-Co the rates of hydrogenation of unsubstituted acetophenones are greater than those of substituted acetophenones with either electron donating or electron attracting groups.
  • Yukihisa Fujita, Yukinao Noda
    1979 Volume 52 Issue 8 Pages 2349-2352
    Published: 1979
    Released: April 19, 2006
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    The thermal denaturation of the deuterated lysozyme has been investigated by differential scanning calorimetry in the range of deuterium oxide (D2O) content from 0.03 to 1.6 g of D2O per g of protein. At D2O contents above 0.55 g/g, the temperature, Td, and enthalpy change, ΔHd, of denaturation were almost independent of the degree of hydration. At lower D2O contents, however, both Td and ΔHd showed marked dependence on the degree of hydration. The values of Td increased with a decrease in the D2O content. Whereas the values of ΔHd decreased with a decrease in the D2O content in the same region. The degree of hydration dependency of ΔHd exhibited a break at approximately 170 mol/mol, which indicates that at least two types of hydration contributes to the thermal stability of the protein. The conformational enthalpy change of the protein and the enthalpy change of the hydration layer have also been estimated from the degree of hydration dependency of ΔHd. The results have been compared with those of the Iysozyme–H2O system.
  • Jun-ichi Ishiyama, Yasuhisa Senda, Isamu Shinoda, Shin Imaizumi
    1979 Volume 52 Issue 8 Pages 2353-2355
    Published: 1979
    Released: April 19, 2006
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    The homogeneous and heterogeneous hydrosilylation of simple substituted cyclohexanones catalyzed by chlorotris(triphenylphosphine) rhodium, RhCl(PPh3)3, and the silica-linked rhodium (I) complex, (Remark: Graphics omitted.), was examined. The stereoselectivity exhibited by the homogeneous catalyst was found to be nearly the same as that exhibited by the heterogeneous catalyst. The silica-linked rhodium catalyst could be re-used several times without any significant loss of the catalytic activity.
  • Seiki Saito, Kenji Doihara, Toshro Moriwake, Kunio Okamoto
    1979 Volume 52 Issue 8 Pages 2356-2361
    Published: 1979
    Released: April 19, 2006
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    Solvolysis of threo-2-(p-methoxyphenyl)-1-methylpropyl brosylate (1) and its deuterium derivative (1-2-d) has been carried out in N,N-dimethylacetamide (DMA) as solvent at 50.0 and 75.0 °C. Product examination revealed that in the presence of water (0.17 mol/dm3) the main product is threo-2-(p-methoxyphenyl)-1-methylpropyl acetate (73% at 50 °C), but in the absence of water (Z)-2-(p-methoxyphenyl)-2-butene (5) (ca. 70% at 50 °C). Both of these products are derived from a threo-imidatonium ion [threo-R-Amide]+ which is produced by DMA capture of the tight ion-pair [R+OBs] (2) from the front-side. A part (ca. 14% yield) of the (Z)-olefin 5 is directly led from the tight ion-pair 2. The formation of the olefin 5 can not be explained by intervention of the phenyl-bridged ion. Although the rate of the brosylate 1 exhibits the kΔ portion deviating upwards from the Hammett plot for a series of threo-2-aryl-1-methylpropyl brosylates, the Schleyer’s kΔ-ks treatment for the rate-(retained)product correlation was unsatisfactory. The classical simple SN1 mechanism can preferably elucidate the product distribution, including the isotope distribution, without intervention of the phenyl-bridged ion intermediate.
  • Seiki Saito, Kenji Doihara, Toshio Moriwake, Kunio Okamoto
    1979 Volume 52 Issue 8 Pages 2362-2368
    Published: 1979
    Released: April 19, 2006
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    Solvolysis of a series of threo-2-aryl-1-methylpropyl brosylates (p-MeO, p-Me, H, p-Cl, m-Cl, m-CF3, and p-NO2; 1ag) has been carried out in four carboxamides, N-methylformamide (NMF), N-methylacetamide (NMA), N,N-dimethylformamide (DMF), and N,Ndimethylacetamide (DMA), as solvent. Fractions of ks and FkΔ pathway were determined on the basis of the upward drift from the Hammett plot of the rate constant (kt); the extra acceleration by p-MeO and p-Me substituents was assigned to the FkΔ fraction. The FkΔkt values were not in agreement with the amount of retained products (threo-acetate and threo-alcohol) obtained in NMA and DMA solvolysis of 1a–c, although they should be in line with each other on the basis of the bridged-ion theory. The C(2)-deuterated phenyl derivative (1c-2-d) was solvolyzed in NMF, NMA, and DMF to give retained carboxylates (acetate or formate). However, the isotope scrambling at C(2) and C(1) of the carboxylates is incomplete, indicating that a symmetrical ion, such as a phenyl-bridged ion, can not be the intermed be the intermediate of the carboxamide solvolysis. A good correlation of logkt for substrates (1ag) with log(% threo-acetate% erythro-acetate) or with log (% threo-acetate% olefinic products) was found for solvent systems such as NMA, DMA, and acetic acid, indicating that the reactions of all substituted substrates can be explained by intervention of a common intermediate [R+X], a classical tight ion-pair from which the final products are derived. Such reactivity-selectivity relationship also holds between log kt’s of 1c in a series of carboxamide and logarithms of threo-erythro ratio in acetate or formate. Through-space interaction between a face of aryl ring and carbenium ion center in the transition state is considered as a possible cause for the anomalous acceleration by the activating aryl groups.
  • Nobuharu Ando, Yukio Yamamoto, Jun’ichi Oda, Yuzo Inouye
    1979 Volume 52 Issue 8 Pages 2369-2371
    Published: 1979
    Released: April 19, 2006
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    Anisochrony of geminal methyls in alkylamines bearing a chiral center in the molecule is affected by complexation with crown ethers, which amplify the chemical shift non-equivalence in NMR. The resolved signal of gem-methyls in valine methyl ester were unequivocally assigned to pro-R and pro-S methyl groups respectively.
  • Akio Horinaka, Eiyu Yo, Otoji Mori, Keizo Naya
    1979 Volume 52 Issue 8 Pages 2372-2376
    Published: 1979
    Released: April 19, 2006
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    Upon autoxidation in alkaline media, pulegone and fukinone (2) gave pairs of hydroxy ketones respectively as the major products; also, hydroxyeremophilone was isolated as its acetate from 2. On the other hand, their dihydro compounds afforded hydroxy ketones, diosphenols, and acids.
  • Tadashi Nakajima, Shinji Masuda, Satoru Nakashima, Takayuki Kondo, Yos ...
    1979 Volume 52 Issue 8 Pages 2377-2382
    Published: 1979
    Released: April 19, 2006
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    The alkylations of benzene with optically active 3-chloro-1-butanol, 3-chlorobutanoic acid and their esters in the presence of aluminium chloride gave the corresponding 3-phenyl substituted derivatives in good optical yield. All these reactions were found to proceed with inversion of configuration at the attacking carbon atom. The products were not racemized under the conditions used, while the starting materials were racemized to a considerable extent during the reaction. Taking into account of the optical purity of the starting material recovered before the completion of reaction, net stereospecificity of each reaction was calculated to be about 90% except for the case of 3-chloro-1-butanol and its acetic ester. The high degree of stereospecificity of the reaction can be interpreted by the mechanism involving cyclic intermediate formed from the alkylating reagent and aluminium chloride.
  • Masahiko Yoshiura, Keiji Iriyama, Masaru Shiraki, Akira Okada
    1979 Volume 52 Issue 8 Pages 2383-2385
    Published: 1979
    Released: April 19, 2006
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    A method for the preparation of chlorophyll-a (Chl-a) and chlorophyll-b (Chl-b) by column chromatography with Sephasorb HP Ultrafine has been developed. The partially purified chlorophyll preparation containing Chl-a, Chl-b and nonsorbed carotenes was applied to a Sephasorb HP Ultrafine column and good separation of Chl-a and Chl-b achieved with a solvent program of (I), a diethyl ether/hexane mixture (1:9, volume ratio) followed by 0.2 and 0.5 vol % isopropyl alcohol in (I). 13.1 mg of Chl-a and 7.6 mg of Chl-b were obtained from 24.7 mg of the partially purified chlorophyll using the above method.
  • Kazu Kurosawa, Hironobu Harada
    1979 Volume 52 Issue 8 Pages 2386-2388
    Published: 1979
    Released: April 19, 2006
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    The reactions of 4-methoxy-, 7-methoxy-, 6,7-dimethoxy-, and 7,8-dimethoxycoumarins with manganese(III) acetate in boiling acetic acid containing acetic anhydride gave 3-(acetoxymethyl) coumarins as the major product. The reactions of coumarin, and 6-methoxy- and 8-methoxycoumarins with manganese(III) acetate yielded a mixture of 3-(diacetoxymethyl)- and nuclear acetoxymethylated coumarins. The reaction of 7-methoxycoumarin with lead(IV) acetate gave 7-methoxy-3-methylcoumarin.
  • Isamu Matsuda, Shizuaki Murata, Yusuke Izumi
    1979 Volume 52 Issue 8 Pages 2389-2393
    Published: 1979
    Released: April 19, 2006
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    α-Cyano carbanions which are generated from γ-trimethylsiloxy nitriles have been found to react with aldehydes to give α-(1-hydroxyalkyl)-γ-trimethylsiloxy nitriles (6). α-Ylidene γ-lactones (5) are derived from 6 in two steps; hydrolytic lactonization to α-(1-hydroxyalkyl) γ-lactones and dehydration. The stereochemistry of the lactones 5 with one exception have been found to be of the E form on the basis of the NMR spectra.
  • Toshimasa Takata, Hajime Matsusaki, Katsuo Ohkata, Terukiyo Hanafusa
    1979 Volume 52 Issue 8 Pages 2394-2398
    Published: 1979
    Released: April 19, 2006
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    Each diastereoisomeric pair of α-(trans-2-p-tolylcyclopropyl) benzyl and α-(trans-2-phenylcyclopropyl)-p-tolylmethyl 3,5-dinitrobenzoates (I-4a, b, II-4a, b) has been synthesized. The relative solvolytic rates of I-4b to I-4a and of II-4b to II-4a in 80% aqueous acetone have been found to be 3.59 and 1.86 respectively at 25 °C. In the presence of 2,6-lutidine, the major products in the solvolysis were homoallylic alcohols.
  • Yoshiro Ogata, Atsushi Kawasaki, Yasuhiko Sawaki, Yoshiaki Nakagawa
    1979 Volume 52 Issue 8 Pages 2399-2401
    Published: 1979
    Released: April 19, 2006
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    The conversion of p-nitrotoluene to p-aminobenzaldehyde was found to be most effectively done by a mixture of Na2S4 and ca. two equivalents of NaOH to p-nitrotoluene. After examination of probable intermediates, toluidine, p-nitrobenzaldehyde and p-nitrosotoluene were discarded as the intermediate. The reaction of carbanion ArCO\={C}HAr with the sulith the sulfide and the effect of some nitrobenzenes as an electron accepter were examined. These results suggest a mechanism involving a simultaneous oxidation-reduction in a nitrotoluene molecule.
  • Toyoki Kunitake, Tetsuo Sakamoto
    1979 Volume 52 Issue 8 Pages 2402-2408
    Published: 1979
    Released: April 19, 2006
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    The catalytic hydrolysis of nitrophenyl sulfates by poly(ethylenimine)(PEI) derivatives was investigated at 30 °C in aqueous buffers. PEI derivatives which were made partly hydrophobic by incorporation of higher alkyl groups include alkylated PEI’s, quaternized PEI’s, and PEI’s with imidazole and hydroxamate functions. Nitrophenyl sulfates could not be cleaved by these polymers. The catalytic hydrolysis of 2-hydroxy-5-nitrophenyl sulfate by an PEI with imidazolylmethyl and dodecyl substituents failed to proceed in spite of the contrary report by Kiefer et al. 2,4-Dinitrophenyl sulfate was cleaved fairly readily by PEI derivatives. Simple sulfate transfer was observed in the case of alkylated PEI, but the catalytic hydrolysis proceeded according to the Michaelis-Menten kinetics in the case of quaternized PEI’s. Partly quaternized PEI’s showed highest catalytic efficiencies reported to date for the hydrolysis of dinitrophenyl sulfate.
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