Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
Volume 63 , Issue 5
Showing 1-50 articles out of 50 articles from the selected issue
  • Kiyomi Ohkawa, Kiminori Itoh, Akira Fujishima
    1990 Volume 63 Issue 5 Pages 1287-1292
    Published: 1990
    Released: June 05, 2006
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    Typical high transition temperature (high-Tc) superconducting oxides were used as electrodes in order to investigate their electrochemical behavior at room temperature. Chemical stability of these materials in various solutions was also tested. These superconducting oxides were stable in nonaqueous solutions, but is was very difficult to protect electrical contacts from the solvents because of porous structures of these oxides. These materials were rather stable in highly concentrated alkaline solutions while unstable in neutral and acid solutions. Electrochemical experiments were carried out in alkaline solutions, and the following results were obtained: (1) All of the high-Tc superconducting oxides were unstable at cathodic polarization. (2) Oxygen evolution was observed under anodic polarization. (3) These oxides behaved like p-type semiconductros though no photocurrents were detected. (4) [Fe(CN)6]3−⁄4− served as a redox couple for all of these high-Tc oxides.
  • Takashi Sumiyoshi, Meiseki Katayama
    1990 Volume 63 Issue 5 Pages 1293-1298
    Published: 1990
    Released: June 05, 2006
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    The formation mechanism of DMSO–halogen atom complexes in the solution of DMSO and halocarbons has been investigated by pulse radiolysis method. Three formation processes have been found depending on the the solution component. In the case of DMSO/CCl4 mixtures, the absorption band at 400 nm due to the complexes has been observed at any composition. In CCl4 solutions, the complex is formed by the reaction of the chlorine atom with DMSO, while in DMSO solutions, the reaction between the parent radical cations of DMSO and Cl is dominant. It is suggested that the contribution of direct excitation of the strongly interacted ground state DMSO–CCl4 encounter pairs becomes more important with increasing CCl4 concentration.
  • Koji Araki, Masahiro Fuse, Noriyuki Kishii, Shinsaku Shiraishi, Teruyu ...
    1990 Volume 63 Issue 5 Pages 1299-1304
    Published: 1990
    Released: June 05, 2006
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    A series of the ruthenium(II) complexes 1–4, [Ru(dabp)3−n(bpy)n](BF4)2 (n=0, 1, 2, and 3, respectively, dabp=6,6′-diamino-2,2′-bipyridine, and bpy=2,2′-bipyridine), having a different degree of interligand steric strain were synthesized, and the effect of the interligand steric strain caused by the amino substituents on their structures was examined. A crystallographic study showed that the two pyridine rings of dabp in the complex 1 were in a slightly twisted configuration in order to relieve the interligand strain. Similar twisted configurations were suggested for the bipyridine moieties of dabp and bpy in the complexes 1–3 in dimethyl sulfoxide solution.
  • Shigeru Isayama
    1990 Volume 63 Issue 5 Pages 1305-1310
    Published: 1990
    Released: June 05, 2006
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    An efficient method for the direct peroxygenation of various olefinic compounds with molecular oxygen and triethylsilane (Et3SiH) was developed by the use of a catalytic amount of a bis(1,3-diketonato)cobalt(II) complex. According to the above method, 1-phenyl-3-triethylsilydioxybutane (2) was directly produced from 4-phenyl-1-butene (1) by means of a reaction with O2 and Et3SiH at room temperature. Styrene (3) and ethyl acrylate (5a) were also smoothly peroxygenated to give 1-phenyl-1-triethylsilyldioxyethane (4) and ethyl 2-triethylsilyldioxypropionate (6a) by using a small amount of t-BuOOH as an initiator. The successive desilylation of 6a and reduction of the resulting ethyl 2-hydroperoxypropionate (8a) afforded the corresponding alcohol, ethyl lactate (10a), in a high yield. The synthetic utility of the present peroxygenation reaction was demonstrated in the preparation of α-hydroxy esters 10a–e from several α,β-unsaturated esters 5a–e via the corresponding triethylsilyldioxy derivatives.
  • Kingo Uchida, Yasuhide Nakayama, Masahiro Irie
    1990 Volume 63 Issue 5 Pages 1311-1315
    Published: 1990
    Released: June 05, 2006
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    1,2-Bis(benzo[b]thiophen-3-yl)ethene derivatives, which possess thermally irreversible and fatigue resistant photochromic properties, were synthesized, cis-1,2-Dicyano-1,2-bis(2-methylbenzo[b]thiophen-3-yl)ethene 1a and 2,3-bis(2-methylbenzo[b]thiophen-3-yl)maleic anhydride 2a underwent reversible photocyclization to produce red-colored closed-ring forms with λmax at 507 nm and 544 nm, respectively. The closed-ring forms were stable for more than 3 weeks at 80 °C. The coloration/decoloration (ring closure/opening)cycles were able to be repeated more than 104 times with keeping the adequate photochromic performance.
  • Tadashi Okuyama, Masayoshi Toyoda, Takayuki Fueno
    1990 Volume 63 Issue 5 Pages 1316-1321
    Published: 1990
    Released: June 05, 2006
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    Methoxymethyl phenyl sulfoxide 1 undergoes acid-catalyzed hydrolysis to give S-phenyl benzenethiosulfinate 5, which is formed rapidly from a primary product, benzenesulfenic acid 3. Formation of 5 follows pseudo-first-order kinetics. Rate constants obtained spectrophotometrically in perchloric acid show that the reaction is dependent on the protonated substrate with the Bunnett–Olsen φ=−0.15. Rate constants for the loss of optical activity of the enantiomeric 1 measured in 80 vol% aqueous dioxane are identical with those obtained spectrophotometrically for the formation of 5. Racemization of the substrate does not take place more rapidly than the fragmentation. The reaction is accelerated by chloride and bromide ions. The halide reaction is first order in acid concentration.
  • Shigeru Nishiyama, Hiroki Kanai, Shosuke Yamamura
    1990 Volume 63 Issue 5 Pages 1322-1327
    Published: 1990
    Released: June 05, 2006
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    An optically active nonchromophore moiety of asteltoxin carrying a hexahydrofuro[2,3-b]furan structure has been successfully synthesized from a branched-chain D-xylohexofuranose derivative.
  • Kikumasa Sato, Seiichi Inoue, Norimichi Iwase,, Kiyoshi Honda
    1990 Volume 63 Issue 5 Pages 1328-1334
    Published: 1990
    Released: June 05, 2006
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    The [2,3]sigmatropic rearrangement of α-substituted N,N-dimethylmethallylamine N-oxides results in a highly stereoselective formation of trans olefins oxygenating at the allylic position, and providing a quite efficient synthesis of cuspidiol and plaunotol.
  • Minoru Sakurai, Hajime Hoshi, Yoshio Inoue, Riichirô Chûj& ...
    1990 Volume 63 Issue 5 Pages 1335-1341
    Published: 1990
    Released: June 05, 2006
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    A reaction-field theory (Hoshi et al., J. Chem. Phys., 87, 1107 (1987)) is applied to the analysis of solvent-induced 13C chemical shift changes of some polyene compounds. The solvent dependence of the 13C chemical shifts is calculated by means of the INDO-finite perturbation method combined with this theory. It is shown that the calculations well reproduce characteristic 13C shift changes observed in aprotic solvents. This indicates the validity of the theory. In addition, the origin of the solvent-induced 13C shifts is discussed on the basis of the electronic distribution obtained.
  • Yoshifumi Tanimoto, Natsuo Okada, Shinji Takamatsu, Michiya Itoh
    1990 Volume 63 Issue 5 Pages 1342-1348
    Published: 1990
    Released: June 05, 2006
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    The magnetic field effects (MFE) on the lifetimes of triplet biradicals generated from the intramolecular photoreaction of bifunctional chain molecules, α-(4-benzoylphenoxy)-ω-[4-(phenylamino)phenoxy]alkanes (BP–O–n–O–DPA, n=2–16) were studied by laser flash photolysis. MFE on the biradical lifetimes are strongly affected by magnetic field, chain length, and solvent. The effects are interpreted in terms of the hf-relaxation mechanism. Lifetime change due to T–S level crossing was observed in the biradicals with n=2 and 4. The singlet and triplet degeneracy of biradicals occurs when n≥6.
  • Kazuhisa Hiratani, Masayo Nomoto, Shoukichi Ohuchi, Kazuhiro Taguchi
    1990 Volume 63 Issue 5 Pages 1349-1353
    Published: 1990
    Released: June 05, 2006
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    The effects of solvents, the concentration of 3,3-bis(8-quinolyloxymethyl)oxetane (1), and the presence of metal ions on the fluorescence intensity of 1 have been investigated. The fluorescence intensity of 1 considerably increased when measured in chloroform, acetonitrile, or dioxane, though resulting in a comparably small increase when measured in ethyl acetate, toluene, or ethylene glycol. When acetone was used as the solvent, the fluorescence spectrum was hardly observed. When the concentration of 1 was adjusted to near 0.1 mmol dm−3, the intensity became maximum in each solvent used, except for acetone. It was observed that the fluorescence intensity of 1 rapidly decreased in a concentration range over 0.1 mmol dm−3. Furthermore, when metal ions were added into an organic solution such as acetonitrile, dioxane, or chloroform containing 1, the maximum increase in the fluorescence intensity was observed in the presence of lithium salt, whereas the intensity hardly changed in the presence of both potassium and sodium ions, compared with that of 1 in the absence of any metal ion. The presence of magnesium and barium ions also hardly brought about an increase of the intensity. On the other hand, heavy metal ions, such as silver(I) and copper(II), were observed to results in a slight decrease.
  • Yutaka Tamaura, Tomoyuki Itoh, Tsutomu Matsuda, Masanori Abe
    1990 Volume 63 Issue 5 Pages 1354-1359
    Published: 1990
    Released: June 05, 2006
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    The anisotropy of the crystal growth of the spinel-type ferrites in an aqueous solution was studied using ferrite films piled up on the glass substrate by means of the thin liquid-film method (TLF method). From the difference between the values of the Oind (the parameter for the degree of the oxidation state), it was found that the Fe3O4 crystal grows in the (111) direction in the “oxidation state” (Oind=1.4×10−2 dm3 min−1), but in the (100) direction in the “Fe2+-rich state” (Oind=3.38×10−4 dm3 min−1). Although the reaction conditions for the formation of the Co(II)– and Zn(II)–ferrites were the same (both used in the “oxidation-state”; Oind=5.5–5.8×10−2 dm3 min−1), the anisotropy of the crystal growth was different between Co2+ [the (111) direction] and Zn2+ [the (100) direction]. These results were explained in terms of difference in the degree of the oxidation state (Oind). For the inverse spinel, the slower rate of the formation of the sublattice of the B site in the “oxidation-state” seems to cause the preferential formation of the A site, since the Fe3+ ions are preferentially incorporated into the A site. This results in the anisotropy in the (111) direction of Fe3O4 and Co(II)–ferrite (inverse spinel). On the contrary, in the “Fe2+-rich state”, the preferential formation of one of the two B sites (the Fe2+ occupies one of the two B sites in the inverse spinel) results in the anisotropy in the (100) direction of Fe3O4. For the normal spinel, the acceleration of the incorporation of the Fe3+ ions into the B site in the “oxidation-state” will result in the anisotropy in the (100) direction. This is the case for the anisotropy in the (100) direction of the Zn(II)–ferrite.
  • Hideo Abe, Etsuo Kokufuta
    1990 Volume 63 Issue 5 Pages 1360-1364
    Published: 1990
    Released: June 05, 2006
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    A coated wire electrode (CWE) was prepared by use of a poly(vinyl chloride)-supported liquid membrane containing oxoethoxo(5,10,15,20-tetraphenylporphyrinato)molybdenum(V) as a carrier. CWE based on such a metallo-porphyrin complex exhibits near-Nernstian responses to varying concentrations of NaOH, NaF, and C2H5OH, especially to NaOH over a wide concentration range. The pOH response curve was influenced by certain anions other than OH ion, but not by cations such as Li+, Na+, K+, and Cs+. The mixed solution method gave a selectivity sequence OH>>ClO4>NO2>F∼SCN>I>NO3>SO3>Br>SO42−, with a preference for OH over ClO4 by 104.6 and over F (or SCN) by 106.2. In addition, Cl ion was found to have little interfering effect under conditions used in the measurements of selectivity coefficients. Both response-time profile and pOH-response curve scarcely varied even when CWE was stored in distilled water for 167 days.
  • Tomoshige Nitta, Yoshiki Yakushijin, Takefumi Kametani, Takashi Kataya ...
    1990 Volume 63 Issue 5 Pages 1365-1369
    Published: 1990
    Released: June 05, 2006
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    The solvent characteristics of super- and subcritical carbon dioxide for the chromatographic resolution of enantiomers (tarns-stilbene oxide) by chiral cellulose tris(phenylcarbamate) were investigated by altering the pressure (10, 15, 20, and 40 MPa), the temperature (0, 25, and 40 °C), and the concentrations of the modifiers. Among methanol, ethanol, and 2-propanol used as modifiers, methanol is the most effective in terms of the resolution of enantiomers, though 2-propanol gives a slightly high value for the separation factor. When the concentration of alcohol increases, the capacity ratio decreases substantially, but the separation factor decreases only a little. At 40 °C, an increase in pressure results in a decrease in the capacity ratio and a slight increase in the separation factor. These pressure effects may be attributed to the enhanced solubilities of both the solute and the modifier with an increase in the mobile-phase density. The temperature is the most effective variable for the separation factor of enantiomers; it increases as the temperature lowers. Therefore, the resolution becomes higher at 0 °C (subcritical conditions) than at 40 °C on the basis of the same analysis time.
  • Hiroshi Ogino, Tetsuo Katsuyama, Setsuo Ito
    1990 Volume 63 Issue 5 Pages 1370-1373
    Published: 1990
    Released: June 05, 2006
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    The kinetics of the substitution reactions of [N′-(2-hydroxyethyl)ethylenediamine-N,N,N′-triacetato]-aquaruthenium(III), [Ru(hedtra)(H2O)], with X (Br, CH3CN, SCN, and pyridine) to give [RuX(hedtra)] were carried out at 25 °C and I=0.5 mol dm−3. The substitution reactions were found to be unusually rapid. The rate constants of the forward reaction (kf) and of the backward reaction (kb) were kf=0.13±0.01 mol−1 dm3 s−1 and kb=(1.9±0.2)×10−2 s−1 for the reaction with Br, kf=0.48±0.02 mol−1 dm3 s−1 and kb=(3.0±0.2)×10−2 s−1 for the reaction with CH3CN, and kf=7.5±0.2 mol−1 dm3 s−1 and kb=(1.3±0.8)×10−2 s−1 for the reaction with SCN, respectively. The kinetics of the reaction of [Ru(hedtra)(H2O)] with py was studied as a function of pH. The observed rate constants of the reaction were separated into two rate constants; the rate constant of the forward reaction of [Ru(hedtra)(H2O)] with py (18±2 mol−1 dm3 s−1) and that of [Ru(OH)(hedtra)] with py (3.0±1.0 mol−1 dm3 s−1). The mechanisms of the reactions are discussed.
  • Fumihiro Ojima, Nagao Kobayashi, Tetsuo Osa
    1990 Volume 63 Issue 5 Pages 1374-1380
    Published: 1990
    Released: June 05, 2006
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    Epoxidation of cyclooctene with molecular oxygen was achieved using electrochemically reduced metalloporphyrins in N,N-dimethylformamide (DMF) containing acetic anhydride as an electrophile. Turnover numbers 5–7 based on moles of cyclooctene oxide produced per moles of porphyrin were obtained by the use of [5,10,15,20-tetrakis(pentafluorophenyl)porphinato]iron(III) chloride and [5,10,15,20-tetra(l-naphthyl)porphinato]manganese(III)chloride. The effects of central metals and substituents on phenyl groups of matalloporphyrins were also investigated. Rate constants (k) were estimated by way of digital simulation of cyclic voltammograms based on a simple ECE reaction mechanism. The reaction mechanism in the presence of cobalt(II) complexes seemed to be somewhat different from that in the presence of iron(III) or manganese(III) complexes.
  • Shigeharu Kittaka, Shigeru Yamanaka, Naoto Yanagawa, Takahiro Okabe
    1990 Volume 63 Issue 5 Pages 1381-1388
    Published: 1990
    Released: June 05, 2006
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    The selectivity sequences of Mg and alkaline earth ions to the surface of α-HCrO2 and Cr2O3 were investigated by measuring the electrophoretic mobility and the surface charge density. The latter was determined by means of potentiometric titration. The selectivity sequence of Mg and alkaline earth ions to the α-HCrO2 surface was determined as Mg>Ca>Sr∼Ba. This sequence was explained by the close configurational fitting of adsorbed metal ions to the solid surface. The reason is that the O–O distance on the (001) plane of Mg(OH)2 and Ca(OH)2 is similar to that of the α-HCrO2. On the amorphous Cr2O3 and crystalline Cr2O3, exposing mainly the (001) plane, the affinity of varying ions was comparable. The isoelectric points (IEP) of the chromium(III) hydroxide oxides and oxides were discussed in connection with their surface crystallinity as determined by electron microscopy. A lower crystallinity gives a slightly higher IEP.
  • Hiroaki Sakurai, Kazuo Urabe, Yusuke Izumi
    1990 Volume 63 Issue 5 Pages 1389-1395
    Published: 1990
    Released: June 05, 2006
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    Fluor-tetrasilicic mica (TSM) exchanged with various types of cations was calcined at 300 °C for 3 h, and a part of the cations were fixed, followed by Al-pillaring. Thus, acidic pillared clay catalysts were prepared with a modification of the silicate layer by cations. Active catalysts for cumene cracking were obtained when modified by Sr2+, Ca2+, La3+, and Li+. The structural changes in the catalysts affecting the reaction activity was examined through X-ray diffraction, surface area, and 29Si-MASNMR measurements. The mode of cation fixation could be classified into five types, depending on the valence and size of the cations to be fixed. A group-2 cation (Na+) gave no modification effect compared with conventional nonmodified PTSM and managed only meager catalytic activity. The catalyst modified by group-5 by (Sr2+, Ca2+, La3+ etc.) cations or a group-1 (Li+) cation had a distinct pillared structure, characterized by an 18 Å basal spacing. These cations could be fixed either onto the basal oxygen surface for group-5 cations or into the octahedral vacancy for a group-1 cation. Though group-4 (Al3+, Mg2+) and group-3 (Cs+, K+) cations should also be fixed into the vacant sites and onto the surface, respectively, both types of modified catalysts formed unstable pillared structures, giving low catalytic activities.
  • Masaharu Okazaki, Keichi Nunome, Kaoru Matsuura, Kazumi Toriyama
    1990 Volume 63 Issue 5 Pages 1396-1401
    Published: 1990
    Released: June 05, 2006
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    The fluorescence detected ESR (ODESR) spectrum of a squalane solution of p-terphenyl was observed at various temperatures, concentrations, and microwave powers. Analysis of the ODESR amplitude, the line shape, and the area under the spectrum which is normalized by the fluorescence intensity led us to conclude that two geminate pairs (one with a terphenyl anion and a hole of the solvent squalane and the other with a terphenyl anion and its cation) contribute to the ODESR spectrum. It was also concluded that the former pair has a much shorter recombination time than that of the latter. It is suggested that though the hole center hops among the solvent squalanes, the rate is much less than that for the hole in aromatic solvents.
  • Masatoshi Asami
    1990 Volume 63 Issue 5 Pages 1402-1408
    Published: 1990
    Released: June 05, 2006
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    Enantioselective deprotonation of meso-epoxides, derived from 3-cyclopenten-1-ol, was examined using chiral lithium amide. Chiral cis-4-t-butyldimethylsiloxy-2-cyclopenten-1-ol, cis-4-tetrahydropyranyloxy-2-cyclopenten-1-ol, and their trans-isomers, which are useful chiral building blocks for the synthesis of cyclopentanoid natural compounds, were obtained with high enantiomeric excesses (72–90% ee). Both (R)- and (S)-4-hydroxy-2-cyclopenten-1-one were derived from (1S,4R)-4-t-butyldimethylsiloxy-2-cyclopenten-1-ol stereospecifically.
  • Tsutomu Tahara, Kahee Fujita, Toshitaka Koga
    1990 Volume 63 Issue 5 Pages 1409-1412
    Published: 1990
    Released: June 05, 2006
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    3-O-(2-Naphthylsulfonyl)-γ-cyclodextrin was prepared together with 2-O-(2-naphthylsulfonyl)-γ-cyclodextrin by a reaction of γ-cyclodextrin with 2-naphthalenesulfonyl chloride in aqueous CH3CN, isolated, and structurally determined.
  • Takashi Muramatsu, Yusaku Ikegami, Kaoru Hanaya, Shinji Onodera
    1990 Volume 63 Issue 5 Pages 1413-1421
    Published: 1990
    Released: June 05, 2006
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    Reduction of 1,1′-(1,3-propanediyl)bis(pyridinium) dibromide (5a) with sodium amalgam afforded the meso- and dl-cyclomers formed by intramolecular cyclization of the diradical (2a). The meso-cyclomer (6a) was thermally converted into the dl-cyclomer (7a), while retroversion of 7a into 6a was achieved photochemically. Reduction of the 4,4′-dimethyl (5b) and 4,4′-di-t-butyl (5c) derivatives of 5a similarly afforded the corresponding meso-(6b and 6c) and dl-(7b and 7c) cyclomers, which can be interconverted to each other. Using NMR spectroscopy to follow the reaction the energies for thermal conversion of meso- to dl- cyclomers were found to be 58.6, 74.5, and 84.5 kJ mol−1 for 6a, 6b, and 6c, respectively. Photodissociation of the cyclomers at −196 °C gave the diradicals (2a–2c), which showed characteristic triplet ESR spectra. The ESR spectra for both 2a and 2b indicated that there were two conformations, each with different zero-field splitting parameters, in 2-methyltetrahydrofuran glass. In contrast, the ESR spectrum of 2c indicated that it has only one conformation. The 4,4′-bis(methoxycarbonyl) derivative (2d) of 2a also forms cyclomers which, upon photolysis, regenerate the diradical. It was concluded that 1,1′-(1,3-propanediyl)bis(pyridinyl) diradicals are substantially in thermal equilibrium with the cyclomers.
  • Yukio Sasaki, Yoshimoto Ishibashi
    1990 Volume 63 Issue 5 Pages 1422-1426
    Published: 1990
    Released: June 05, 2006
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    The physical properties of 3-propylsydnone at various temperatures were investigated by dielectric constant, refractive index, density and viscosity measurements. The dielectric constant (ε) of 3-propylsydnone is very high compared to those of many organic solvents. For example, this value was found to be 95.0 at 25 °C. The dielectric constant of 3-propylsydnone is approximately expressed by a cubic equation of the temperature. The Kirkwood equation holds over the range from 10 to 150 °C. The refractive index (nD) and density (ρ) data for 3-propylsydnone are described as linear equations of the temperature with maximum deviations of 0.008 and 0.005%, respectively. The viscosity (η) of 3-propylsydnone at 25 °C is 8.45 cP (1 cP=10−3 N s m−2). This value is larger than those of many organic solvents, but smaller than those of sulfolane and 1,2-ethanediol. A plot of logη vs. 1/T for 3-propylsydnone yields a straight line. The activation energy of the viscosity for 3-propylsydnone was found to be 25.0 kJ mol−1.
  • Hiroshi Matsui, Akira Kunugi
    1990 Volume 63 Issue 5 Pages 1427-1432
    Published: 1990
    Released: June 05, 2006
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    Methanol oxidation at a platinum electrode in 0.5 mol dm−3 sulfuric acid at high potentials was retarded by the formation of both an oxygen layer and a new type of retarding substance from methanol. The presence of the retarding substance was confirmed by the oxygen-deposition method. During retardation due to the formation of an oxygen layer, the rate of methanol oxidation both decreased and increased with increasing oxygen coverage and potential, respectively. The reverse efcets of oxygen coverage and potential concurrently occurred when the potential was a variable. At low oxygen coverage, the decreased effect of oxygen coverage was more remarkable than the increased effect of the potential, while the order of the remarkableness was reversed at middle coverage. The reversal of the order could be explained in terms of a catalytic reduction of the oxygen layer with methanol.
  • Michitaka Ohtaki, Naoki Toshima, Makoto Komiyama, Hidefumi Hirai
    1990 Volume 63 Issue 5 Pages 1433-1440
    Published: 1990
    Released: June 05, 2006
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    Ultrafine particles of platinum were prepared as stable aqueous dispersions by a photoreduction method in the presence of soluble protective polymers. By use of the protective polymer with methyl acrylate residues as a reactive group, the polymer-protected ultrafine platinum particles were successfully immobilized onto crosslinked polymer supports with amino groups. The present immobilization was attributed to the formation of amide bonds by the reaction of methyl acrylate residues in the protective polymer with amino groups in the support, and the immobilization mechanism was investigated by the model reaction using protective polymer with p-nitrophenyl acrylate residues as a reactive group. The immobilized platinum particles obtained show high catalytic activity for hydrogenation of olefins and specific substrate selectivity due to a hydrophilic–hydrophobic interaction between the support and the substrate.
  • Harumichi Kobashi, Hiroshi Suto, Haruo Shizuka
    1990 Volume 63 Issue 5 Pages 1441-1446
    Published: 1990
    Released: June 05, 2006
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    Decay kinetics of triplet-state ion pairs (3IPs) have been studied for the termolecular systems consisting of the chloranil anion radical (CA\ ewdot) with the dimer cation radical of naphthalene (Np\underset.+) or its monohalogenated derivatives (NpX2\underset.+) in 1,2-dichloroethane by means of laser photolysis. Marked heavy-atom (HA) effect was found on back electron transfer (back ET) but not on ionic dissociation (ID). A small effect of 1- or 2-brominated compound on 3IP lifetimes was observed. Both back ET and ID processes of 3(CA\ ewdot, Np2\underset.+) were found to be almost temperature-independent. Electron-transfer (ET) quenching of 3CA leading to produce the (1:1) 3IP was also independent on the HA substitution. For these kinetic studies, a conventional decay analysis was examined.
  • Kan Kanamori, Hidekazu Dohniwa, Naoya Ukita, Isao Kanesaka, Kiyoyasu K ...
    1990 Volume 63 Issue 5 Pages 1447-1454
    Published: 1990
    Released: June 05, 2006
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    The Raman spectra of iron(III) complexes with ethylenediaminetetraacetate were observed for the purpose of elucidating the structure of the complexes in solution. In a Raman spectral study on the solid complexes, the spectra in the 300–600 cm−1 region were found to be diagnostic to coordination geometry. Namely, the coordination number can be determined on the basis of the wavenumber difference of the two major bands observed in the 450–600 cm−1 region; the wavenumber differences observed for heptacoordinate complexes lie between 32 and 42 cm−1, while that for the hexacoordinate complex is 62 cm−1. Complexes containing a sexidentate edta exhibit a single intense band around 470 cm−1 in the 450–500 cm−1 region, while complexes containing a quinquedentate edta exhibit two intense bands in this region. These Raman spectral criteria were then applied for the determination of the solution structure. The Raman spectral features observed for solutions of Fe(III)-edta complexes indicate that the any alkali metal salts and acid salts of FeIII(edta) give sexidentate heptacoordinate complex ions in water. The dimeric complex which is formed in an alkaline solution was characterized as being a dinuclear complex consisting of two quinquedentate hexacoordinate iron(III) moieties with a Fe–O–Fe bridging unit.
  • Masanobu Watanabe, Hirotoshi Sano
    1990 Volume 63 Issue 5 Pages 1455-1461
    Published: 1990
    Released: June 05, 2006
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    The adducts of osmocene derivatives with Lewis acids were studied by means of 13C-CP-NMR spectroscopy and other physicochemical techniques. The large low-field shifts found through 13C-CP-MAS NMR and 1H NMR spectroscopy and the organotin(IV) species found in the 119Sn-Mössbauer spectroscopic data suggest the presence of direct chemical bonds between the osmium atoms and the Lewis acids in the adducts.
  • Hiroshi Yokoi, Akira Takeuchi, Shoichiro Yamada
    1990 Volume 63 Issue 5 Pages 1462-1466
    Published: 1990
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    Twenty one of the title complexes (abbreviated as Cu(X–sal–R)2; X=H, 5-Cl, or 5-Br and R=N-alkyl) in toluene have been extensively studied by the ESR method in order to obtain fundamental information on dimer formability and the dimeric structures of these complexes. The equilibrium constant (K) for 2 monomer \ ightleftharpoons dimer has been determined by analyzing the concentration dependence of the intensity ratios of the dimer to the monomer ESR signals for frozen toluene solutions. The K values of the Cu(H–sal–R)2 complexes are remarkably R-dependent as follows: methyl (233)>>ethyl (10)∼isobutyl (9)>other normal alkyl groups (∼4) for a series of the R groups with primary α-carbons, and cyclohexyl (75)>>isopropyl (7)>s-butyl (<<1)>cycloheptyl (∼0)>t-butyl (0) for a series of the R groups with secondary and tertiary α-carbons, where the complex is denoted by R, followed by K (M−1) in parentheses. The complexes with R=nonyl or higher homologues form some polymeric species besides dimers and monomers. The K values remarkably increase by the introduction of X=5-Cl or 5-Br. The observed dimer ESR spectra have been analyzed by computer simulation in order to estimate the structural parameters (r and ξ) of parallel-planar dimers, where r is the Cu–Cu distance and ξ is the angle between the Cu–Cu direction and the normal to the molecular plane. These results indicate that most complexes form two types of dimers with different structures: type a, r=3.75 Å and ξ=37°; type b, r=4.10 Å and ξ=23°. The Cu(X–sal–methyl)2 complexes form only a-type dimers, while the others simultaneously form both types of dimers, except the complexes of R=isopropyl and cyclohexyl which form another type of parallel-planar dimers having a slightly tetrahedrally-distorted coordination geometry around each copper atom.
  • Kan-ichi Hasegawa, Makoto Sakakibara, Tetsuya Ishida, Yoshio Ueno
    1990 Volume 63 Issue 5 Pages 1467-1477
    Published: 1990
    Released: June 05, 2006
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    The equimolecular condensation of 2-aminobenzenethiol (1) with 4,8-bis(alkylamino)-1,5-naphthoquinones (2) in ethanol in the presence of HCl gave near-infrared-absorbing 1,5-bis(alkylamino)-4H-benzo[a]phenothiazin-4-ones (3), which existed as predominant tautomers in various solvents. The reaction mechanism was proposed to involve pathways through the O-protonation of 2, followed by the attack of 1 on the resulting ion, the subsequent oxidation, and the acid-catalyzed intramolecular cyclization of the quinonoid intermediate. The tautomeric equilibria of 2, 3, and 5,8-dihydroxy-1,4-naphthoquinone favor the formation of an interconverting hydrogen atom of a higher electron density. The solvatochromic effect of 3 was analyzed by means of the linear solvation energy relationships.
  • Yoshikazu Sugimoto, Yasuo Miki, Masaaki Oba, Shoko Yamadaya
    1990 Volume 63 Issue 5 Pages 1478-1483
    Published: 1990
    Released: June 05, 2006
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    Aromatic constitutents in Wandoan coal-derived distillate were analyzed by means of capillary gas chromatography/mass spectrometry (GC/MS) in order to clarify their aromatic skeletal structures. The major aromatic skeletons could be classified into several groups, the molecular weights of which were represented by 78+50n, 118+50n, 154+50n, 166+50n, 202+50n, 242+50n (n=0,1,2,···), and so on. The increase by 50 corresponded to an additional benzene ring fused to the original skeleton. Some new types of aromatic skeletons, such as dihydrophenalene and benzindan, were found to be present in significant amounts.
  • Masato M. Ito, Masahiro Onda, Seiichi Ona, Hakuai Inoue
    1990 Volume 63 Issue 5 Pages 1484-1488
    Published: 1990
    Released: June 05, 2006
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    A kinetic study on poly (p-phenylene sulfide) formation from p-dichlorobenzene (1) and sodium sulfide reveals that the initiation rection is first order with respect to 1 and sodium sulfide, respectively. Reaction on the surface of solid sodium sulfide has proved to be negligible when the reaction is carried out in the presence of the solid. The time course of the concentration of 1 and its dimer can be explained with a simplified eight step kinetic model for the initial stage, in which each of the step is firest order with respect to the reactant in concern. Kinetic parameters for each of the steps were estimatied. Increase in [Na2S]/[1] ratio causes the increase both in polymer yield and in the degree of polymerization. Presence of a small amount of water enhances cosiderably the rate of polymerization and increases the polymer yield, but the highest degree of polymerization was observed in the presence of water approximately equimolar to 1.
  • Swapan K. Bhattacharya, Kiron K. Kundu
    1990 Volume 63 Issue 5 Pages 1489-1495
    Published: 1990
    Released: June 05, 2006
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    The rate constants (skR) of K++e (Hg)\ ightleftharpoonsK(Hg) in the dipolar aprotic solvents like propylene carbonate (PC), N, N-dimethylformamide (DMF), acetonitrile (AN), and their several binary mixtures have been determined at 25 °C on a hanging mercury drop electrode (HMDE) by cyclic voltammetric measurements. The observed nature of the cyclic voltammograms indicates that the reaction is quasi-reversible in the range of the sweep rates 1.0–0.01 V s−1. An insight to the composition profiles of the free energies of activation (ΔG) relative to that in the chosen reference solvent (r) in the respective solvent (s) systems: −δΔG(=RTln skRrkR) reveals that not only the solvation of K+ but also that the transition state (TS) are responsible in dictating the rate constants. Also the solvation of TS is being guided by the dispersion interactions as well as the availability of the fraction of the free surfaces (1–θs) for varying adsorption of the solvent molecules on the electrodes, all relative to that of the respective reference solvents.
  • U. S. Rai, K. D. Mandal
    1990 Volume 63 Issue 5 Pages 1496-1502
    Published: 1990
    Released: June 05, 2006
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    The phase diagram of p-phenylenediamine–m-nitrobenzoic acid system, determined by the thaw-melt method, show the formation of two eutectics and a 1:2 addition compound. The linear velocity of crystallization of pure components, eutectics and addition compound, measured by determining the rate of movement of growth front in a capillary, suggests that crystallization data obey the Hillig–Turnbull equation. Using experimental values of heats of fusion, determined by the DTA method, entropy of fusion, heat of mixing and excess thermodynamic functions were calculated and the results are explained on the basis of cluster formation in the melts. Microscopic studies reveal that the eutectics have different characteristics microstructures as compared to those of parent components. X-Ray diffraction data suggest that there is preferential ordering of atomic planes in the formation of the eutectics.
  • R. K. Swain, L. K. Tiwary, B. Behera
    1990 Volume 63 Issue 5 Pages 1503-1507
    Published: 1990
    Released: June 05, 2006
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    The apparent molar volume and the viscosities of N-methylpyridinium iodide and its methyl derivatives in water at 25, 30, 35, and 40 °C are reported. The apparent molar volumes obey Masson’s equation. The φv° and Sv* values indicate strong ion–ion interaction in water. φv° is linearly related to temperature. The relative viscosity data of these salts obey Jones–Dole and Vand equations well. The A and B values of Jones–Dole equation and Q values of Vand equation suggest greater solvation in case of NMPI and the β-CH3 salt and greater ion–ion interaction in case of α-CH3 and γ-CH3 salts. The data have been discussed in terms of hydrophobic hydration and solvent shared ion pairs. The free energy of activation for viscous flow are almost equal for these salts. The importance of A, B, B+, and Q to the study of the solvent structure is discussed.
  • N. M. Sundaramurthi, V. M. Shinde
    1990 Volume 63 Issue 5 Pages 1508-1511
    Published: 1990
    Released: June 05, 2006
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    A simple and rapid method is proposed for the extraction, separation, and spectrophotometric determination of palladium from salicylate media using Aliquat 336 dissolved in xylene as an extractant. The optimum conditions were evaluated from a critical study of pH, salicylate concentration, Aliquat 336 concentration, and period of equilibration. The palladium in the Aliquat 336 phase is determined spectrophotometrically with 4-(2-pyridylazo)resorcinol (PAR) at 530 nm. The proposed method described the scheme for the separation of platinum, nickel, copper, cobalt, zinc, and manganese from binary mixtures. The method was extended to the analysis of palladium catalyst and platinum ores.
  • Narinder S. Poonia, Ramesh Chandra, W. S. Sheldrick
    1990 Volume 63 Issue 5 Pages 1512-1514
    Published: 1990
    Released: June 05, 2006
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    2-Hydroxyethanaminium picrate, HOCH2CH2NH3+·C6H2N3O7, is prepared through a metathetical reaction of Mg(Pic)2 and HOCH2CH2NH2 (2-aminoethanol, MEA) in ethanol through in situ generation of HPic. Orange yellow crystals (MEAH+Pic) (mp 163°C) of the “Salt” are produced alongwith the colorless Mg(CH2NH2CH2O)2, even when MEA is less than 1:1 with respect to Mg(Pic)2. The crystals are monoclinic, space group P21/c, a=11.797(4), b=14.288(3), c=7.124(2) Å, β=97.63(2)°, Z=4, Dcal=1.62 g cm−3. Structural analysis from the 1617 reflection data (R=0.059, Rw=0.056) reveals that the picric acid proton is formally transferred to the MEA nitrogen (N–H, 0.968 Å) and is merely bonded to the phenoxide of Pic (H···O, 1.951 Å) and weakly also to an oxygen of o-nitro group of the anion (H···ONO, 2.379 Å). The transferred proton becomes an integral part of the cation MEAH+ and completes the fourth covalent bond of the sp3 N of MEA, and does not show any special affinity for the anionic oxygen of Pic; the N–H···O (142.8°) and N–H···ONO (141.6°) angles are closely comparable.
  • K. G. Varshney, Upma Gupta
    1990 Volume 63 Issue 5 Pages 1515-1520
    Published: 1990
    Released: June 05, 2006
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    A new phase of a lead-selective cation exchange material, tin(IV) antimonate has been prepared, which possesses a good column exchange capacity (2.4 mequiv g−1). Its characterization has been done on the basis of its ion-exchange characteristics and some instrumental studies such as TGA, IR, and X-ray diffraction. The utility of the material has been demonstrated by achieving some binary separations of metal ions on its column, such as Al(III)–Pb(II), Mg(II)–Pb(II), Fe(III)–Pb(II), Al(III)–Fe(III), Mg(II)–Al(III), and Mg(II)–Fe(III). Maximum limits of the column’s loading capacity have also been evaluated for all metal ions.
  • Jagdish Prasad Rawat, Abdul Aziz Ansari
    1990 Volume 63 Issue 5 Pages 1521-1525
    Published: 1990
    Released: June 05, 2006
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    An inorganic ion exchanger sodium stannosilicate has been synthesized. Its composition, chemical and thermal stabilities and ion exchange properties have been studied. This material is obtained as hard granules and is very stable at high temperatures. Its ion exchange capacity for Ag+ is 2.25 mequiv g−1. The material shows high selectivity towards Ag+ which has been separated quantitatively from Pb2+, Hg2+, and Cu2+. Recovery of Ag+ from dilute solutions has also been studied.
  • Shunzo Yamamoto
    1990 Volume 63 Issue 5 Pages 1526-1528
    Published: 1990
    Released: June 05, 2006
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    The quenching rate constants of Zn(3PJ) by methane and cyclopropane at various temperatures were determined on the basis of the Stern-Volmer plots. The activation energy for the quenching by methane was similar to that by cyclopropane. The frequency factor for the quenching-rate constant by cyclopropane was very large.
  • Kazumasa Yoshikai, Toshikazu Hieida, Yoshinori Nibu, Hiroko Shimada, R ...
    1990 Volume 63 Issue 5 Pages 1529-1531
    Published: 1990
    Released: June 05, 2006
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    Assignment of the normal vibrations of 4-methylpyridine was made through the vibrational analyses of the Raman and infrared spectra and also through the normal coordinate calculation. The assignment was confirmed by the study made on 4-methyl-d3-pyridine.
  • Norio Saito, Yutaka Ikushima, Tomio Goto
    1990 Volume 63 Issue 5 Pages 1532-1534
    Published: 1990
    Released: June 05, 2006
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    The solubilities of the acetylacetone chelates in supercritical CO2 (SC-CO2) at 333 K and 9.8–29.4 MPa were strongly influenced by the extraction pressure, and by the nature of the metals and the number of acetylacetone ligands in the chelates. It was found that acetylacetone chelates could be extracted selectively by SC-CO2 treatment because of significant differences in their solubilities in SC-CO2.
  • Tsuneo Yanagisawa, Toshio Shimizu, Kazuyuki Kuroda, Chuzo Kato
    1990 Volume 63 Issue 5 Pages 1535-1537
    Published: 1990
    Released: June 05, 2006
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    Alkyltrimethylammonium–kanemite complexes, having three dimensional SiO2 networks, were allowed to react with a trimethylsilylating reagent to form the trimethylsilylated derivatives. The three dimensional SiO2 networks were retained after trimethylsilylation. The calcined products obtained from the trimethylsilylated products had about 840–880 m2 g−1 in specific surface areas and micro pores with 22–33 Å in average pore diameter. These values were slightly smaller than those of the calcined products obtained from alkyltrimethylammonium–kanemite complexes, which indicated the effect of the trimethylsilyl groups.
  • Takamasa Kinoshita, Noritaka Yoshida, Toshio Miwa
    1990 Volume 63 Issue 5 Pages 1538-1539
    Published: 1990
    Released: June 05, 2006
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    Acetylation of 2-C-benzyl-L-ascorbic acid afforded an unexpected enone, 2,6-di-O-acetyl-2-C-benzyl-5-deoxy-D-glycero-hex-4-en-3-ulosono-1,4-lactone (3) of the open form, along with 2,3,5-tri-O-acetyl-2-C-benzyl-L-lyxo-3-hexulosono-1,4-lactone (4) of the closed form.
  • Ko Nakamura, Chikara Ohira, Hiroshi Yamamoto, Wolfgang Pfleiderer, Kaz ...
    1990 Volume 63 Issue 5 Pages 1540-1542
    Published: 1990
    Released: June 05, 2006
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    The structure for a product of the oxidation of creatinine is revised to be N-(N′-methylamidino)oxamic acid (4). Acyclic product 4 and its cyclic product, 2-amino-1-methyl-4,5-imidazoledione, are coined as creatones B and A, respectively. The first synthesis of 2-methylamino-4,5-imidazoledione is also described.
  • Noritaka Abe, Yoshifumi Emoto
    1990 Volume 63 Issue 5 Pages 1543-1545
    Published: 1990
    Released: June 05, 2006
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    Reaction of 2-chlorocyclohepta[b]pyrrole-3-carbaldehyde with o-phenylenediamine gave 1H-2-(2-chlorocyclohepta[b]pyrrol-3-yl) benzimidazole (3a) and 5H-12,13-dihydrocyclohepta[1′,2′:4,5]pyrrolo[2,3-b][1,5]benzodiazepine (4a). Some reactions of 3a and 4a were also described.
  • Mitsuo Hayashida, Nobuo Sakairi, Hiroyoshi Kuzuhara
    1990 Volume 63 Issue 5 Pages 1546-1548
    Published: 1990
    Released: June 05, 2006
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    A 2′,6′-diamino-1,6-anhydro disaccharide derivative (6) was prepared from maltose. The 3′,4′-diol system of 6 was successfully converted into the 3′-ene system by application of the Corey–Winter procedure, giving the hex-3′-enopyranose derivative (8). Catalytic hydrogenation of 8 gave the dideoxy derivative, a key intermediate for the synthesis of a new aminoglycoside.
  • Seiichiro Ogawa, Masaaki Urakawa, Takeshi Tonegawa
    1990 Volume 63 Issue 5 Pages 1549-1551
    Published: 1990
    Released: June 05, 2006
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    Three stereoisomers of DL-1-C-(hydroxymethyl) conduritol epoxides have been synthesized in order to investigate their inhibitory activity against certain glycosyl hydrolases.
  • Kiyomi Okabe, Kenji Matsuzaki, Hiroyuki Hagiwara
    1990 Volume 63 Issue 5 Pages 1552-1554
    Published: 1990
    Released: June 05, 2006
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    Crystalline calcium silicate of ZSM-5 structure was hydrothermally synthesized by using an excessive amount of tetrapropylammonium bromide (TPABr) as an organic base and without using any alkali metal ions in the low pH range. The acidity caused by Ca was verified by IR, NH3-TPD, and methanol conversion.
  • Tsuneji Sano, Hideo Okado, Hiroshi Shoji, Shigeru Ikai, Haruo Takaya
    1990 Volume 63 Issue 5 Pages 1555-1557
    Published: 1990
    Released: June 05, 2006
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    For the ZSM-5 zeolite mechanically mixed with barium carbonate, the migration of barium into the zeolite channels from the outer surfaces of zeolite crystals occurs at 600 °C in both the absence of and the presence of steam, resulting in a modification of the strong acid sites.
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