Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
Volume 63 , Issue 1
Showing 1-50 articles out of 64 articles from the selected issue
  • Miyuki Ishimura, Hisashi Uedaira
    1990 Volume 63 Issue 1 Pages 1-5
    Published: 1990
    Released: June 05, 2006
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    The spin-lattice relaxation times, T1, of H217O have been measured for the aqueous solutions of 11 apolar amino acids and 5 glycine peptides as a function of the concentration at 25°C. The coordination numbers, nh, and the rotational correlation times, τch, of water molecules around the amino acids and peptides were estimated and compared with that of pure water, τc0. The value of τch⁄τc0=1.87 for norleucine is the largest, while those of τch⁄τc0 for glycine peptides are almost the same 1.2. The value of nhch⁄τc0−1) was defined as the dynamic hydration number (DHN). The DHN showed a good correlation with several physicochemical properties, such as the molecular weights, partial molar volumes, adiabatic compressibilities, heat capacities, B-coefficients of the activity coefficent, and limiting diffusion coefficients of amino acids and glycine peptides in aqueous solutions.
  • Koichiro Miyajima, Hiroaki Komatsu, Kazuhiro Inoue, Tetsurou Handa, Ma ...
    1990 Volume 63 Issue 1 Pages 6-10
    Published: 1990
    Released: June 05, 2006
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    The degradation of Methyl Orange (MO) by singlet oxygen was inhibited by the addition of α-, β-, and γ-cyclodextrins (CD’s) to an aqueous solution. The protective effect of the CD’s against the MO oxidation decreased in this order; α->γ-\gtrsimβ-CD. From the relation between the rate constant of MO oxidation and the free MO concentration, evaluated by using the formation constants of CD’s with MO, it was found that the MO included by α and γ-CD’s is not decomposed by singlet oxygen, whereas the MO included by β-CD is oxidized by singlet oxygen. The inner cavity of α- or γ-CD well fit for the inclusion of one or two MO molecules respectively, and the access of singlet oxygen to the azo group of the included MO molecule is sterically inhibited. The finding that β-CD has smaller enthalpy and larger entropy changes relevant to the formation of the MO–CD complex than those of α- and γ-CD’s suggested the less tight inclusion of one MO molecule in the cavity of β-CD. Such a loose inclusion of MO by β-CD resulted in the transient exposition of the azo group of the MO molecule to the bulk phase: the attack of the singlet oxygen on the azo group followed.
  • Kazunori Matsui, Takumi Nakazawa
    1990 Volume 63 Issue 1 Pages 11-16
    Published: 1990
    Released: June 05, 2006
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    Silica sols and gels doped with pyrene (Py) and pyrene-3-carboxaldehyde (PyCHO) were prepared by the acidic hydrolysis of tetraethyl orthosilicate in ethanol. We studied the fluorescence of these molecules during the sol–gel–xerogel stages. The fluorescence intensity ratio of the vibronic bands of Py changed remarkably, while the fluorescence maximum of PyCHO showed a significant red shift as the gel dried. Such a spectral change was ascribed to an increase in the environmental polarity of the probe molecules upon the evaporation of the ethanol. The estimated dielectric constant of the gel after drying in a vacuum is about 72, just slightly less polar than water (80). The silica cage produced by the sol–gel process is probably rich in silanols, resulting in a relatively polar environment.
  • Masanobu Matsuguchi, Makoto Aratono, Kinsi Motomura
    1990 Volume 63 Issue 1 Pages 17-20
    Published: 1990
    Released: June 05, 2006
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    The interfacial tension between hexane solution of cholesterol and water was measured as a function of temperature and the mole fraction of cholesterol in hexane under atmospheric pressure. The interfacial tension vs. mole fraction of cholesterol curve was observed to have two break points at a certain temperature; the concentration of the break point increases with increasing temperature. The experimental results were analyzed by applying the rigorous thermodynamics of adsorption at interfaces developed previously. The excess number of moles of cholesterol and the thermodynamic quantity changes associated with its adsorption were found to show the discontinuous changes at the break points. It was concluded that the first-order phase transition takes place from the gaseous to the expanded state and from the expanded to the condensed one in the adsorbed film of cholesterol at the hexane/water interface.
  • Nobuo Nakamura, Hiroshi Yoshino
    1990 Volume 63 Issue 1 Pages 21-25
    Published: 1990
    Released: June 05, 2006
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    In a previous paper which examined the molecular rotation in sym-C6Cl3F3 crystal by the 35Cl NQR an unrealistically long activation parameter, τ0, for the molecular rotation was obtained by assuming the three-fold molecular uniaxial reorientation. In order to examine the reason for such unacceptable result the relaxation time (T1) data were reanalyzed with the help of the computer experiment which calculates the rotational potential function for each molecule in the crystal lattice. The computation was carried out using the 6-exponential type interatomic pair potential functions. It was found that the potential for the plane molecular rotation in the hexagonal unit cell is non-sinusoidal and has, in addition to the most stable orientation, an extra minimum where the molecules can stay for a finite time at moderately high temperatures. The rotational potential thus obtained was used successfully to reanalyze our previous T1 data for this material. 35Cl NQR T1’s were measured for C6Cl6 crystal and analyzed using anisotropic rotational potentials. The analysis predicted possible disordered structure of this material. In the case of C6F6 it was confirmed that the in-plane rotation of two crystallographically inequivalent molecules can be excited with different activation energies from each other, being consistent with the previous fluorine NMR work.
  • Sadakatsu Nishikawa, Yumiko Moritsubo, Fumiharu Matsuo, Yosiaki Endo
    1990 Volume 63 Issue 1 Pages 26-32
    Published: 1990
    Released: June 05, 2006
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    Ultrasonic absorption, velocity and density measurements were carried out in aqueous solutions of 1-methoxy-2-propanol and 3-(3-methoxypropoxy)propanol as a function of their concentrations at 25°C. A single ultrasonic relaxational phenomenon was observed in both solutions in the frequency range from 6.5 to 220 MHz. The cause was attributed to a perturbation of an equilibrium associated with the solute solvent interaction, AB(Remark: Graphics omitted.)A+B, from the concentration dependences of the relaxation frequency and the amplitude of the relaxational absorption. The rate and thermodynamic parameters were determined for the above process. It was found that the methoxyl group introduced in alcohol molecule acted as a water structure breaker while the propoxyl group promoted the water structure. Speculation of excess ultrasonic absorption in various monohydroxy alcohol aqueous solutions was carried out from the present data. In order to further confirm the participation of the solvent water molecule in the observed relaxation process, absorption measurements were carried out in methanol, dimethyl sulfoxide, and their mixed solvents with water for 3-(3-methoxypropoxy)propanol.
  • Munetaka Oyama, Koichi Nozaki, Tsutomu Nagaoka, Satoshi Okazaki
    1990 Volume 63 Issue 1 Pages 33-41
    Published: 1990
    Released: June 05, 2006
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    The reactions of 9,10-diphenylanthracene cation radical (DPA) with water and alcohols in acetonitrile (AN) were studied using a novel column-electrolytic stopped-flow spectrophotometric method. The reaction was first-order with respect to DPA in all reactions. The reaction orders of other reactants were determined by plotting the logarithms of the apparent first-order rate constants (kapp’s) against the logarithms of the concentration of reactants. The plot of logkapp vs. log [alcohols] was linear, and hence the reaction was clearly determined to be second-order. On the other hand, the logkapp vs. log [water] plot did not show a linear relationship. Similar results were obtained in the reactions of 9,10-dimethylanthracene cation radical with water and methanol. Comparing the results obtained with water and alcohols, and considering the changes in the physicochemical properties of the AN–water medium, it was concluded that the reaction of water was second-order, though it had been believed previously to be first-order. Products of the reactions are trans- and cis-9,10-dialkoxy-9,10-diphenyl-9,10-dihydroanthracene in many cases.
  • Satoru Onaka, Sigeru Takagi, Hiroyuki Furuta, Yoshio Kato, Atushi Mizu ...
    1990 Volume 63 Issue 1 Pages 42-46
    Published: 1990
    Released: June 05, 2006
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    17O NMR spectra have been measured for series of cobalt carbonyl cluster derivatives, RCCo3(CO)9−x(PPh3)x, (RC2R′)Co3−xyFexMoy(CO)9−yCpy, and R3−xSn[Co(CO)4]x+1. The small 17O-chemical shift differences due to the change of R and/or introduction of PPh3 have been interpreted in terms of the electron buffer action of the Co3 core for RCCo3(CO)9−x(PPh3)x. Good linear correlations between 17O-chemical shifts and CO stretching frequencies have been observed for these derivatives. Some effect of the magnetic anisotropy resulted from the ring current along the metal-triangle on 17O-chemical shifts has been suggested for metal-triangle clusters.
  • Tsuneo Yanagisawa, Chika Yokoyama, Kazuyuki Kuroda, Chuzo Kato
    1990 Volume 63 Issue 1 Pages 47-50
    Published: 1990
    Released: June 05, 2006
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    Layered polysilicic acid–acrylamide intercalation compounds were synthesized by the reaction of H-magadiite (H2Si14O29·xH2O) and H-kenyaite (H2Si20O41·xH2O) with acrylamide saturated aqueous solutions. The formation of the intercalation compounds were ascertained by X-ray powder diffraction, IR, 13C-CP MAS NMR, DTA, and chemical analysis. However, when H-magadiite was used, a part of the intercalated acrylamide molecules was oligomerized during the intercalation. A heat treatment of the layered polysilicic acid–acrylamide intercalation compounds led to a polymerization of the acrylamide in the interlayer spaces.
  • Junji Tanaka, Shuji Kanemasa, Otohiko Tsuge
    1990 Volume 63 Issue 1 Pages 51-56
    Published: 1990
    Released: June 05, 2006
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    Phenyl 1-(trimethylsilyl)propadienyl sulfide undergoes a hydroalumination with diisobutylaluminum hydride (DIBAH) or lithium butyl(diisobutyl)aluminum hydride (BL-DIBAH). The adduct anion derived from DIBAH is regioselectively trapped with carbonyl compounds at the position α to the phenylthio moiety to give 1,3-dienes as Peterson olefination products; the anion derived from BL-DIBAH is trapped at the position γ to the phenylthio moiety to give 3-buten-1-ols. Silylmetalation and stanylalumination on the same acceptor have been also briefly investigated as equivalent reactions.
  • Yozo Miura, Tetsuya Ohnishi, Masayoshi Kinoshita, Takamasa Kinoshita
    1990 Volume 63 Issue 1 Pages 57-63
    Published: 1990
    Released: June 05, 2006
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    The reaction of Nphenylsulfonyl-3,5-di-t-butylphenylaminyl radical (2) with unsaturated aromatic and aliphatic hydrocarbons has been carried out in degassed benzene at 75°C. The reactions of 2 with unsaturated aromatic hydrocarbons gave 1:1, 1:2, and 2:1 adducts of 2 and the hydrocarbons in fair to good yields. On the other hand, in the reactions of 2 with unsaturated aliphatic hydrocarbons, hydrogen-abstraction by 2 from the hydrocarbons was the major reaction. In the reaction with 2-methylpropene, a product indicating the addition of 2 to 2-methylpropene was isolated in a 16% yield. On the basis of these results the reactivity of 2 is discussed and compared with that of structurally related N(4-chlorophenylthio)-3,5-di-t-butylphenylaminyl radical.
  • Masahiko Kato, Shigeyuki Yamamoto, Shigeki Nomura, Toshio Miwa
    1990 Volume 63 Issue 1 Pages 64-73
    Published: 1990
    Released: June 05, 2006
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    In order to obtain a scope and limitations of the reaction for newly developed tropone synthesis, some substituted 2,3- and 3,4-epoxy-7,7-dihalobicyclo[4.1.0]heptanes have been prepared and treated with several acids. We found that (1) the epoxy-carbons of starting materials should have, at least, one substituent which may stabilize the carbenium ion formed by cleavage of the epoxide with acid, (2) as halogens in the starting materials, bromine is superior to chlorine, (3) use of 20 molar equivalent of TFA to a substrate in chloroform at refluxing temperature or use of each 5 molar equivalent of TCA and water to a substrate in toluene at 100°C is recommended.
  • Masako Sakuragi, Kousou Aoki, Takashi Tamaki, Kunihiro Ichimura
    1990 Volume 63 Issue 1 Pages 74-79
    Published: 1990
    Released: June 05, 2006
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    The effects of intermolecular and intramolecular triplet quenchers and sensitizers on the photochromism of nitrospiropyran have been examined in order to clarify the role of the triplet state (3A*) as well as that of the excited singlet state (1A*). The rates of photocoloration and fatigue were significantly affected: the quenchers retarded both rates, while the sensitizers retarded the former but enhanced the latter rate. It can be concluded that more than 90% of the total amount of photomerocyanin is generated from 1A* in the photostationary state and that fatigue proceeds mainly through 3A*.
  • Masahiko Iyoda, Hiroki Otsuka, Koichi Sato, Nobue Nisato, Masaji Oda
    1990 Volume 63 Issue 1 Pages 80-87
    Published: 1990
    Released: June 05, 2006
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    Reduction of NiX2(PPh3)2 with zinc in the presence of Et4NI gives a nickel catalyst which has been proven to be useful for the coupling of aryl halides. This nickel catalyst can be prepared in THF without an additional triphenylphosphine and is effective for the homocoupling of aryl chlorides, bromides, and iodides to produce biaryls and bipyridines in good yields. The reported new approach provides a simple access to novel derivatives of biaryls and bipyridines.
  • Makoto Ando, Jun Watanabe, Hiroyoshi Kuzuhara
    1990 Volume 63 Issue 1 Pages 88-90
    Published: 1990
    Released: June 05, 2006
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    A chelate complex (4) with high homogeneity was precipitated upon stirring a mixture of zinc(II) ion and a Schiff base produced from glycine and (R)- or (S)-15-formyl-14-hydroxy-2,8-dithia[9](2,5)pyridinophane, chiral pyridoxal-like pyridinophane. A four-coordinated zinc chelate complex was newly proposed as the structure of 4. Aldol condensations between 4 and several aldehydes were attempted at pH 10.0. Only small linear chain aldehydes, such as acetaldehyde and propionaldehyde, could react with 4 under these conditions to give the corresponding α-amino-β-hydroxy acid in the range of 27–77% enantiomeric excess.
  • Kaoru Nakamura, Takashi Kitayama, Yoshihiko Inoue, Atsuyoshi Ohno
    1990 Volume 63 Issue 1 Pages 91-96
    Published: 1990
    Released: June 05, 2006
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    (S)-(+)-4-Nitro-2-butanol (1) obtained by the stereoselective reduction of 4-nitro-2-butanone by bakers’ yeast was employed for the syntheses of natural products. A precursor of (+)-brefeldin A is synthesized starting from this chiral building block by 10 steps short-cut procedure compared with the shortest method so far reported. (S)-(+)-Sulcatol is obtained in much better enantiomeric purity than those reported. The reactivity of 1 in base-catalyzed condensations with Michael acceptors or aldehydes is largely affected by a base employed as the catalyst.
  • Yuichi Shimizu, Shun’ichi Sugimoto, Shunichi Kawanishi, Nobutake ...
    1990 Volume 63 Issue 1 Pages 97-101
    Published: 1990
    Released: June 05, 2006
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    The photoinduced transformation of methanol (MeOH) has been investigated in the presence of H2O2. Ethylene glycol (EG) was selectively produced by UV light irradiation of the N2-saturated MeOH and the selectivity was 85–94% below 3 ml h−1 of H2O2 feeding rate (f). The quantity of EG reached the maximum at f=5 ml h−1 and the quantum yield was 0.73. EG was produced through the dimerization of hydroxymethyl radicals formed by the abstraction of hydrogen atom from MeOH by hydroxyl radical which was formed by the photolysis of H2O2. On the other hand, formic acid (FA) and methyl formate (MF) were selectively produced by UV light irradiation of the O2-bubbled MeOH and the combined selectivity was about 99% in the f range of 1–8 ml h−1. The quantities of FA and MF reached the maximum at f=5 ml h−1 and their quantum yields were 1.36 and 0.69, respectively. FA was mainly produced through the decomposition of hydroperoxyhydroxymethane formed by the abstraction of hydrogen atom from MeOH by hydroxymethyldioxy radical which was formed by the reaction of hydroxymethyl radical with oxygen, and MF through the reaction of MeOH with FA formed.
  • Shuichi Hamada, Yoshiyuki Kudo, Kazuhiro Minagawa
    1990 Volume 63 Issue 1 Pages 102-107
    Published: 1990
    Released: June 05, 2006
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    Rather poorly crystallized spherical particles of indium(III) hydroxide were produced by forced hydrolysis at 100°C for 120 min under the conditions of 6.0×10−4 mol dm−3 for indium(III) ions, 1.0×10−3 mol dm−3 for nitric acid, and 1.25 for a concentration ratio, [SO42−]t/[In3+]t, respectively, having an average size of 0.48 μm with a relative standard deviation of 0.09. On the other hand, cubic particles of well-crystallized indium(III) hydroxide were yielded in a nitrate solution that was free from sulfate ions and at the same concentrations. The cubic particles grew through a polynuclear layers mechanism. Monomeric hydroxo complexes basically acted as precursors of the spherical particles, together partly with polymeric ones. The point of zero charge was estimated as being at the same pH (7.7) for both the hydroxide and oxide particles prepared from the nitrate system, in contrast to those of 7.0 and 5.4 for the respective particles obtained from the sulfate system.
  • Yasuo Saitoh, Satoshi Ohtsu, Yasuo Makie, Takashi Okada, Kenji Satoh, ...
    1990 Volume 63 Issue 1 Pages 108-115
    Published: 1990
    Released: June 05, 2006
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    The turnover frequency (TF) for the methanol decomposition over various supported Pd catalysts is dependent upon both supporting materials and Pd crystallite sizes. On the other hand, the apparent activity (gas evolution rate per g-catalyst) is roughly proportional to the degree of Pd dispersion. This variation in the apparent activity is related to starting materials for the preparation of supports as well as to properties of supports. The highest dispersion of Pd was obtained with TiO2 prepared from Ti[OCH(CH3)2]4 or TiCl4, but at an elevated temperature (above 773 K) in the reduction treatment applied, it showed a suppressed activity. Pd particles on ZrO2 support gave a high value of TF when the Pd/ZrO2 catalyst was calcined in air at an elevated temperature (873–1073 K). The findings about the influence of heat treatment suggest that thermal stabilization of the ZrO2 support would play an important role in the development of catalytic properties of Pd. TF curves for the methanol decomposition over TiO2- and ZrO2-supported Pd catalysts change discontinously at about 10 Å of Pd particle size. In the case of Al2O3 support, characteristic behavior of TF curve are significantly different from those observed in the case of TiO2 and ZrO2 supports.
  • Akio Nakamura, Masakatsu Koshinuma, Kazuo Tajima
    1990 Volume 63 Issue 1 Pages 116-120
    Published: 1990
    Released: June 05, 2006
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    Copper(II) complexes of amphoteric surfactants, N-alkyl-β-alanine (NAA) (the number of carbon atoms in the alkyl chains: n=2, 4, 6, 8, 10, 12), Were synthesized from NAA and copper(II) chloride dihydrate by mixing in aqueous solutions. The properties and structures of these bluish flaky complexes were investigated by elemental analyses, infrared and far-infrared spectroscopy, electronic diffuse reflection spectroscopy, X-ray diffractometry, and thermal analyses. As a result, all of these complexes were found to be composed of one copper(II) ion and two NAA molecules, regardless of the chain length in the alkyl group, (Cu(NAA)2·2H2O), and were also found to have a laminated structure in the crystalline state. A linear relationship was found between the long spacings (d/nm) of the laminated structure and the numbers of carbon atoms (n) in the N-alkyl substituents; d=0.135n+0.62. From these results it was concluded that copper(II) complex molecules have a trans configuration, and are extended and parallel to the normal line of the laminated planes in the crystal. A multiunilayer model for the molecular arrangement of these copper(II) complexes has been proposed, which is quite different from those so far proposed to explain the long spacings observed for metal soap crystals, lyotropic liquid crystal and so on. Also, the role of the alkyl substituents in complex formation has been indicated.
  • Gorou Arai, Kiyofumi Matsumoto, Toshiyuki Murofushi, Iwao Yasumori
    1990 Volume 63 Issue 1 Pages 121-125
    Published: 1990
    Released: June 05, 2006
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    The electrodeposition of Pd at microgram levels onto an electroconductive poly(hydroquinone/p-benzoquinone) film-coated glassy carbon electrodes is described. The polymer films were chemically modified with Pd pyridine complex and/or with Pd thiolate prior to the Pd electrodeposition. Controlled-potential electrolysis was applied to form Pd microparticles on the polymer film from an acid PdCl2 solution. The nucleation/growth of Pd microparticles was largely promoted by these chemical modifications. The Pd particles on the pyridine complex-modified electrode were closely dispersed and were spherically shaped, while on the thiolate-modified electrode the Pd deposits were irregular in shape. Both the electrodes thus prepared exhibited high activity toward the generation of hydrogen and had good stability in acidic solution.
  • Shozi Mishima, Isao Matsuzaki, Tsuyosi Nakajima, Toshimichi Hiki
    1990 Volume 63 Issue 1 Pages 126-130
    Published: 1990
    Released: June 05, 2006
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    An aluminium-containing polymethylsiloxane (AMS) was prepared in an aqueous system using methyltrichlorosilane, dimethyldichlorosilane, and aluminium hydroxide as the starting materials, and its applicability as a new solid acid catalyst was examined. AMS is an amorphous hydrophobic solid with a high surface area (ca. 250 m2 g−1) and a relatively high thermal stability (max. 573 K in air). The adsorption of basic indicators indicated that acid sites with a medium strength (pKa=1.5) exist on AMS, and protic acid sites were detected on AMS by the IR spectra of adsorbed pyridine. These acid sites differ from the aprotic sites found on alumina. Though those on AMS are able to catalyze the dehydration of pinacol in the vapor phase, they are inactive for the hydrolysis of methyl acetate in an aqueous system.
  • Hiroshi Miyasaka, Noboru Mataga
    1990 Volume 63 Issue 1 Pages 131-137
    Published: 1990
    Released: June 05, 2006
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    The mechanism of photoreduction of benzophenone (BP) by diphenylamine (DPA) in isooctane as well as acetonitrile and other polar solvents has been investigated by means of picosecond laser photolysis and time-resolved transient absorption spectral measurements. The results of measurements have demonstrated clearly that the hydrogen abstraction and charge transfer (CT) or ion pair (IP) state formation by electron transfer are competing at encounter between triplet benzophenone (3BP*) and DPA both in nonpolar and polar solvent, and the CT or IP state relaxed with respect to the donor acceptor configurations and solvation does not contribute to the ketyl radical formation. It has been concluded that the very short-lived CT state at encounter between 3BP* and DPA plays a crucial role in the hydrogen abstraction reaction, i.e. the mutual orientation of 3BP* and DPA in this very short-lived CT state at encounter will determine the successive process, the formation of the ketyl radical or relaxed CT or IP state.
  • Yuki Fujii, Yuzo Yoshikawa, Masato Syoji, Homare Shinohara
    1990 Volume 63 Issue 1 Pages 138-146
    Published: 1990
    Released: June 05, 2006
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    The stability constants, K1, of Δ2-diastereomers of mixed ligand cobalt(III) complexes with a chiral quadridentate Schiff base (sal-(R,R)-chxn), derived from salicylaldehyde and (R,R)-1,2-cyclohexanediamine, and D- or L-amino acidate (aa=gly, ala, val, leu, thr, phe, trp, pro, asp, asn, and glu) were determined spectrophotometrically in water–methanol (2:3 by volume) containing acetate buffer (0.3 mol dm−3) at 22°C: trans-[Co{sal-(R,R)-chxn}(H2O)2]++aa\oversetK1\ ightleftharpoonsΔ2-[Co{sal-(R,R)-chxn}(aa)]. The K1 values range from 5.6×106 to 1.2×109 mol−1 dm3 and obey a linear free energy relationship except for D-phe, D-trp, D-asp, D-asn, and D-pro. In the cases of D-phe, D-trp, D-asp, and D-asn, their stability constants are 5–30 times as high as those for the corresponding L-aa. Extraordinary stabilization of the D-phe and D-trp complexes is discussed in terms of the interligand stacking of the aromatic rings between the Schiff base ligand and a side chain of amino acidate on the basis of conformational analysis and 1H NMR spectra.
  • Akio Makishima, Yukihiro Yamamoto, Kohji Watanabe
    1990 Volume 63 Issue 1 Pages 147-150
    Published: 1990
    Released: June 05, 2006
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    The average valency of iron in the oxide layer on iron particles for magnetic recording and the saturation magnetization of the oxide layer were estimated to be 2.8 and 39 emu g−1, respectively, by examining the Debye temperature and the recoilless fraction of oxide layer which were calculated with the Mössbauer parameters.
  • Masaru Kimura, Miwako Ohota, Keiichi Tsukahara
    1990 Volume 63 Issue 1 Pages 151-155
    Published: 1990
    Released: June 05, 2006
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    The kinetics and mechanism of the decomposition of the bis(oxalato)manganese(III) complex ion ([Mn(ox)2]) were studied in acid solution in the absence and in the presence of oxygen at temperatures from 10 to 35°C. The decomposition reaction of [Mn(ox)2] in the absence of oxygen was described by the first-order rate law of −d[[Mn(ox)2]]/dt=kobsd[[Mn(ox)2]], where the observed rate constant, kobsd, increased proportionally with the increasing hydrogen-ion concentrations, being expressed as kobsd=k[H+] in the [H+] range of 0.006–0.1 M. The enthalpy and entropy changes of activation(ΔH\ eweq and ΔS\ eweq) were 73.4±2.0 kJ mol−1 and −8.6±0.2 J K−1 mol−1 respectively. The rate of the decomposition of [Mn(ox)2] decreased greatly upon the addition of a radical scavenger for CO2\ ewdot such as [Co(NH3)6]3+, [CoCl(NH3)5]2+, or molecular oxygen. In the presence of oxygen, the rate deviated greatly from the first-order rate law. On the other hand, the addition of [Co(NH3)6]3+ or [CoCl(NH3)5]2+ in the absence of oxygen did not change the first-order rate law, but did decrease the rate of reaction up to 40% of that in the absence of the radical scavenger. The mechanisms for the decomposition reaction of [Mn(ox)2] are discussed in the light of the results obtained.
  • Yuichiro Haramoto, Hiroyoshi Kamogawa
    1990 Volume 63 Issue 1 Pages 156-158
    Published: 1990
    Released: June 05, 2006
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    (+)-4-(5-Alkyl-1,3-dioxan-2-yl)phenyl 4-(2-methylbutoxy)benzoates (9) and their oxathiane (10) and dithiane (11) analogs have been synthesized. The mesomorphic behavior of these compounds was measured. Compounds 9 exhibited a ferroelectric liquid-crystal behavior (e.g. R=n-C10H21: 51 SmC* 57.5°C), while the corresponding 1,3-oxathianes (10) and 1,3-dithianes did not.
  • Shuji Ichinose, Akitsugu Okuwaki
    1990 Volume 63 Issue 1 Pages 159-165
    Published: 1990
    Released: June 05, 2006
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    A kinetic study of the oxidation of benzenecarboxylic acids has been performed in order to clarify the mechanism. The reaction products were oxalic acid and carbon dioxide, along with a trace of acetic acid. The oxidation rate of phthalic acid was proportional to the first order of the molality of phthalic acid, the molality of NaOH, and partial oxygen pressure, respectively; the apparent activation energy was 126 kJ mol−1. These results show that the rate-determining step is a cleavage of the benzene ring proceeded by a base-catalyzed oxygen-oxidation mechanism in which a carbanion formed by hydrogen extraction from an aromatic ring is attacked by oxygen. In the cleavage of phthalic acid, NaOH increases the selectivity to form oxalic acid as well as the oxidation rate. In the oxidation of 1,2,3-benzenetricarboxylic acid the same mechanism was recognized, but not for benzenehexacarboxylic acid which has no hydrogen on the benzene ring.
  • Takahiro Hosokawa, Yoshiharu Ataka, Shun-Ichi Murahashi
    1990 Volume 63 Issue 1 Pages 166-169
    Published: 1990
    Released: June 05, 2006
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    Alkenes bearing electron-withdrawing substituents are catalytically acetalized with 1,3-propanediol only by the use of PdCl2(MeCN)2 catalyst under O2 atmosphere. When a combination of BiCl3 and LiCl is used as co-catalyst, the acetalization proceeds effectively. These results indicate that a hydroperoxopalladium(II) species is most likely an active catalyst in the present reaction.
  • Kazuhiro Maruyama, Shigeki Kawabata
    1990 Volume 63 Issue 1 Pages 170-175
    Published: 1990
    Released: June 05, 2006
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    A series of conjugated polyyne porphyrins, in which two porphyrin macrocycles are connected with both ends of diarylpolyyne through aromatic ring, has been prepared and their spectroscopic behaviors were investigated. Diarylpolyyne consisting of aryl group and conjugated triple bond system have rigid and linear structure, and the two porphyrins are held at a fixed geometry and a determined distance. In their absorption spectra, porphyrin Soret bands were red- or blue-shifted depending on their edge-to-edge or face-to-face orientation.
  • Shoichi Shimizu, Yasuyuki Sasaki, Choichiro Hirai
    1990 Volume 63 Issue 1 Pages 176-178
    Published: 1990
    Released: June 05, 2006
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    Bromoanisoles have been reduced to hydrocarbons with sodium formate in high yields under mild conditions using palladium on charcoal and cyclodextrins as catalysts. In aqueous phase-organic phase reactions employing a solid-phase catalyst (Pd/C), cyclodextrins function as inverse phase-transfer catalysts which transfer the substrate into the aqueous phase.
  • Koji Kato, Tohru Yamada, Toshihiro Takai, Satoshi Inoki, Shigeru Isaya ...
    1990 Volume 63 Issue 1 Pages 179-186
    Published: 1990
    Released: June 05, 2006
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    In the presence of a bis(1,3-diketonato)cobalt(II) complex, various olefins are converted to the corresponding hydrated products according to the Markownikov rule on treatment with molecular oxygen in secondary alcohol (“oxidation–reduction hydration”). Removal of water formed during the hydration reaction, especially by azeotropic method, is remarkably effective to improve yields of the hydrated products based on the cobalt(II) catalyst as bis(trifluoroacetylacetonato)cobalt(II) (Co(tfa)2) or bis(2-ethoxycarbonyl-3-oxobutanalato)cobalt(II) (Co(ecbo)2).
  • Keiichi Mitsuta, Yukio Mizuta, Masahiro Kohno, Midori Hiramatsu, Akita ...
    1990 Volume 63 Issue 1 Pages 187-191
    Published: 1990
    Released: June 05, 2006
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    The SOD-like activity of several biological substances was evaluated by an ESR spin-trapping technique. Superoxide radicals (O2\ ewdot) were supplied enzymatically from a hypoxanthine–xanthine oxidase reaction to the evaluating system. By using a spin trap 5,5-dimethyl-1-pyrroline N-oxide (DMPO), the generated O2\ ewdot was trapped stoichiometrically (1:1) as the spin adduct of O2\ ewdot (DMPO–O2). When biological substances were added to the system, a decrease in the ESR signal intensities of the adducts was observed. This phenomenon could be explained as being an inhibition of adduct formation, and related to the reactivity of added biological substances with O2\ ewdot, called an SOD-like activity. By the method of kinetic competition with a 50% inhibitory dose (ID50), the second-order rate constant for the reaction between O2\ ewdot and biological substance was determined. These rate constants can be used as a measure of the reactivity.
  • Shuji Tanabe, Hiroshige Matsumoto
    1990 Volume 63 Issue 1 Pages 192-198
    Published: 1990
    Released: June 05, 2006
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    EXAFS measurements have been employed to investigate structural changes of Cu species in Y-zeolite during TPR process. The formation of an active species by a consecutive reduction-reoxidation treatment was clearly demonstrated in the TPR spectra. Detailed analysis of the EXAFS data suggested that at a considerably low temperature the active species was reduced directly to Cu metal with a particle size of 5–8 Å, while at higher temperatures the original Cu2+ ions were reduced by a two-step mechanism, via Cu+ ions to Cu metal. From these points of view, the active species is considered to be small clusters of CuO with several Cu atoms.
  • Mamoru Ai
    1990 Volume 63 Issue 1 Pages 199-202
    Published: 1990
    Released: June 05, 2006
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    The effects of the reaction variables on the yields of the aldol condensation products, i.e., acrylic acid and methyl acrylate, in the reaction of acetic acid with methanol in the presence of gaseous oxygen was studied using a V–Ti–P ternary oxide catalyst with an atomic ratio of 1:2:6, respectively. The best catalyst performance was obtained with an oxygen/methanol molar ratio of between 0.5 to 0.75. The yield of acrylic acid decreased with increasing the methanol concentration, while that of methyl acrylate increased; the sum of the two yields increased with methanol concentration above 360°C. The feed rate did not have much effect on the yield, except at high conversions. Better catalytic performance was observed with longer contact times at lower temperatures than with shorter contact times at higher temperatures.
  • Shinsaku Fujita
    1990 Volume 63 Issue 1 Pages 203-215
    Published: 1990
    Released: June 05, 2006
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    A novel method of enumerating isomers is presented by using adamantane as a parent skeleton. This method is based on unit subduced cycle indices with and without chirality fittingness, the indices being derived from the subduction of coset representations. The chirality fittingness, which is determined by examining the relationship between a point group and its subgroup, controls the mode of substitution by achiral and chiral substituents. The method provides detailed enumerations concerning symmetries and molecular formulas, whereas Pólya’s theorem takes only the latter into consideration.
  • Kozo Inuzuka, Akira Fujimoto
    1990 Volume 63 Issue 1 Pages 216-220
    Published: 1990
    Released: June 05, 2006
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    The UV absorption spectrum of 2,6-diaminopyridine was measured in an ethanol-and-isooctane mixed solvent while increasing the concentration of ethanol at room temperature and changing the temperature from 20 to −100°C at a constant concentration of ethanol. Its spectrum showed a clear shoulder band near 345 nm as the concentration of ethanol increased to over 5×10−1 mol dm−3 at room temperature and as the temperature decreased from 20 to −100°C in 1×101 mol dm−3 of ethanol in the isooctane solution. The corresponding band near 345 nm was observed for 2-amino-6-methylaminopyridine and 2,6-bis(methylamino)pyridine; however, it was not found for 2-amino-6-dimethylaminopyridine, 2-methylamino-6-dimethylaminopyridine, or 2,6-bis(dimethylamino)pyridine in the same experiments. The shoulder band near 345 nm was, on the basis of the spectroscopic results and the molecular orbital method, assigned to the π–π* absorption band of the (E)-6-amino-2(1H)-pyridinimine formed through the hydrogen-bond formation of 2,6-diaminopyridine with two ethanols. The formation of the imino form with two ethanols may be restricted to the 2,6-diaminopyridine and its methyl derivatives, in which each amino group at the 2- and 6-positions has at least one hydrogen atom. The proton transfer from ethanol to 2,6-diaminopyridine in the 2,6-diaminopyridine-ethanol complex may be energetically difficult in the ground state.
  • Kazuharu Yoshizuka, Yoshinari Baba, Katsutoshi Inoue, Fumio Wada, Tsut ...
    1990 Volume 63 Issue 1 Pages 221-226
    Published: 1990
    Released: June 05, 2006
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    N,N-Dioctylsuccinamic acid was synthesized to examine the selectivity for various metals in extractions from hydrochloric acid. It was found to be highly selective for palladium(II), platinum(IV), and mercury(II) over other base metals including copper(II), nickel(II), cobalt(II), zinc(II), iron(III), aluminum(III), and gallium(III). A quantitative study was conducted on the extraction equilibria of palladium(II) and platinum(IV) from aqueous chloride media with N,N-dioctylsuccinamic acid in toluene, together with measurement of the apparent molecular weight of the extractant. It was elucidated that the extractant (HR) dimerizes in toluene and that palladium(II) and platinum(IV) are extracted according to the following reactions:
    &PdCl_4^2-+‾H_2R_2 \oversetK_e,Pd\ ightleftharpoons ‾PdR_2+2H^++4Cl^-
    & PtCl_6^2-+‾H_2R_2 \oversetK_e,Pt\ ightleftharpoons ‾PtCl_4·2HR+2Cl^-
    The extraction equilibrium constants of palladium(II) and platinum(IV) with the extractant were evaluated as follows: Ke,Pd=0.11±0.03 (mol·dm−3)5 and Ke,Pt=27.7±3.7 mol·dm−3, respectively.
  • Masanobu Tsuchimoto, Masakazu Kita, Matsuo Nonoyama, Junnosuke Fujita
    1990 Volume 63 Issue 1 Pages 227-234
    Published: 1990
    Released: June 05, 2006
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    New cobalt(III)-1,4,7,10-tetraazacyclotetradecane (N47), -pentadecane (N48), and -hexadecane (N49) complexes, trans-[CoCl2(N4x)]+ (x=7 (two isomers), 8 (two isomers), 9 (one isomer)), trans-[Co(NO2)2(N4x)]+ (x=7, 8, 9, one isomer), cis-[Co(NO2)2(N47)]+ (one isomer), and [Co(en)(N4x)]3+ (x=7, 8, one isomer) were synthesized and characterized. For analogous 1,4,7,10-tetraazacycloundecane (N46) complexes, two isomers for each of cis-[Co(NO2)2(N46)]+ and [Co(en)(N46)]3+ were also obtained and were found to isomerize to each other in acetonitrile. The ligand field parameters of nitrogen Δ(N) and chlorine Δ(Cl) estimated from the observed ligand field bands of trans-[CoCl2(N4x)]+ show a correlation between them; with an increase in ring size of N4x, the Δ(N) value decreases, while the Δ(Cl) value increases. The reduction potentials for each series of the dichloro, dinitro, and en complexes become less negative with an increase in ring size of N4x.
  • Yoshiyuki Kudo, Teruyoshi Kimura, Shuichi Hamada
    1990 Volume 63 Issue 1 Pages 235-240
    Published: 1990
    Released: June 05, 2006
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    Crystals of 1,2,3,4,6,7-hexathia-5,8-diazocine (1,4-S6(NH)2) were transformed around 363 K with a molar enthalpy change of the transformation of 2.40±0.07 kJ mol−1. Crystal systems of the two forms of 1,4-S6(NH)2 were identified to be orthorhombic (α-form) and monoclinic (β-form) below and above this temperature. Molar heat capacities of the α- and β-forms were also deduced as being 0.1950±0.001 and 0.199±0.001 kJ mol−1 K−1 at 298.15 K, respectively. The 1,4-S6(NH)2 was pyrolyzed around its apparent melting point (405 K), producing tetrasulfur tetranitride (S4N4) and tetrasulfur dinitride (S4N2) as solid intermediates, which finally decomposed into sulfur, nitrogen, and ammonia under an argon atmosphere. A stoichiometric correlation among the final products gave an overall pyrolytic equation: 1,4-S6(NH)2=3⁄4S8+2⁄3N2+2⁄3NH3. The standard enthalpy of the formation of α-form 1,4-S6(NH)2 was estimated as being 158±2 kJ mol−1 according to the observed enthalpy changes of the pyrolysis and transformation, which reasonably agreed with that calculated.
  • Yukihiro Yokoyama, Kensuke Takahashi
    1990 Volume 63 Issue 1 Pages 241-243
    Published: 1990
    Released: June 05, 2006
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    The 13C NMR parameters for 1- and 2-naphthylmethanide ions were obtained in two polar solvents, THF and HMPA. Excess charge distributions in the ions are discussed in connection with the nature of the solvents.
  • Kazushi Arata, Makoto Hino, Nobutsugu Yamagata
    1990 Volume 63 Issue 1 Pages 244-246
    Published: 1990
    Released: June 05, 2006
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    Acidity and catalytic activity of Zr(SO4)2 and Ti(SO4)2 calcined at 500–800°C were studied. The products obtained by calcination at 725°C for Zr(SO4)2 and at 625°C for Ti(SO4)2 showed the highest activity for the cracking of cumene among samples calcined at other temperatures; the former showed an acid strength of −13.16<H0≤−12.70 and the activity for the reaction of pentane.
  • Pangbu Hong, Takaya Mise, Hiroshi Yamazaki
    1990 Volume 63 Issue 1 Pages 247-248
    Published: 1990
    Released: June 05, 2006
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    In the presence of Co4(CO)12, Rh4(CO)12, and Ir4(CO)12 catalysts the reaction of diphenylacetylene (1) in 2-propanol under pressure of carbon monoxide gave the hydrocarbonylation products 2 and/or 3 and the oligomers 4 and/or 5, in which the ratios depended on the catalyst employed.
  • Takaji Fujiwara, Naoki Tanaka, Ryuzou Ooshita, Ryoji Hino, Koji Mori, ...
    1990 Volume 63 Issue 1 Pages 249-251
    Published: 1990
    Released: June 05, 2006
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    The crystal and molecular structure of the title complex was determined by X-ray method. The absolute configuration of the host (+)-2,2′-dihydroxy-1,1′-binaphthyl (1) was determined to be R and the guest (−)-(ethyl m-tolyl selenoxide) (2) to be S. Two Se–C and one S-O bond lengths are 1.926(7), 1.970(8), and 1.677(5) Å, respectively, and the arrangement around Se atom is roughly tetrahedral. There are O(guest)···HO(host)OH···O(guest) hydrogen bonds between the host and the guest molecules.
  • Yoshimi Sueishi, Norio Nishimura, Koichi Hirata, Keiji Kuwata
    1990 Volume 63 Issue 1 Pages 252-254
    Published: 1990
    Released: June 05, 2006
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    The activation volumes for the spin exchange of 2,2,6,6-tetramethyl-4-oxo-1-piperidinyloxyl (Tanone) in protic and aprotic solvents were determined from the pressure dependence of the rate constants, and were compared with those for the diffusive process. It was concluded that the rate process for the spin exchange in aprotic solvents is a diffusion-controlled one, and in protic solvents an encounter complex as intermediate is formed. The average reaction volume for the complex formation in protic solvents was estimated to be −3.6 cm3 mol−1.
  • Toshihide Baba, Keiichiro Kameta, Satoru Nishiyama, Shigeru Tsuruya, M ...
    1990 Volume 63 Issue 1 Pages 255-257
    Published: 1990
    Released: June 05, 2006
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    Pd0 supported on K-L zeolite suspended in a liquid phase has a high catalytic activity and a high selectivity for the oxidative lactonization of butane-1,4-diol into γ-butyrolactone under oxygen at 391 K.
  • Makoto Shibagaki, Kyoko Takahashi, Hideyuki Kuno, Hajime Matsushita
    1990 Volume 63 Issue 1 Pages 258-259
    Published: 1990
    Released: June 05, 2006
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    Hydrous zirconium oxide is an amorphous solid and has several catalytic activities. The oxide was changed to crystalline zirconia by calcination at a high temperature, and the catalytic activities were lowered. The correlation between the surface property and the catalytic activity was investigated on hydrous zirconium oxide calcined at several temperatures; the best activity was obtained in the oxide calcined at 300°C.
  • Yoshihiro Mitsutsuka, Erkin Tursun, Masayoshi Nakahara
    1990 Volume 63 Issue 1 Pages 260-261
    Published: 1990
    Released: June 05, 2006
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    New preparation methods are reported for some fluoroamminecobalt(III) complexes. The polarized spectra were measured by microspectrophotometry for some complexes. Coordination geometries of the complexes were predicted from the spectral data.
  • Shunjiro Ikegawa, Takashi Nogami, Yasuhiko Shirota
    1990 Volume 63 Issue 1 Pages 262-264
    Published: 1990
    Released: June 05, 2006
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    Transition-metal salts of 2-oxo-1,3-dithiole-4,5-dithiolate (dmio) were synthesized in order to develop highly conducting organic complexes. Their redox potentials were measured and compared with those of the related 1,2-dithiolate salts.
  • Isao Sanemasa
    1990 Volume 63 Issue 1 Pages 265-266
    Published: 1990
    Released: June 05, 2006
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    The vapor pressure of each constituent of the title binary mixtures, except for 1-octanol, was measured by the headspace gas chromatography as a function of biphenyl or naphthalene mole fraction in a relative scale taking the vapor pressure of the pure component as unity.
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