Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
Volume 64 , Issue 6
Showing 1-50 articles out of 63 articles from the selected issue
  • Akio Miyata, Yutaka Unuma, Yoshiyuki Higashigaki
    1991 Volume 64 Issue 6 Pages 1719-1725
    Published: 1991
    Released: June 07, 2006
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    The optical properties of monomolecular layers at an air–water interface and also of Langmuir–Blodgett (LB) films of several photochromic spiropyrans with a single hydrophobic long chain and either a hydroxyl or a hydroxymethyl group have been investigated. Changes in the optical spectra of these films were induced by either UV irradiation or heating. UV-visible, and IR absorption spectra showed that spiropyran SP145 formed J-aggregates and SP147 formed H-aggregates. The half-decay period of the J-aggregate to the spiropyran (SP) form was longer than that of the colored monomeric photomerocyanine (PMC) to the SP form. It was concluded that hydrogen bonding between neighboring colored PMC molecules via hydroxyl, hydroxymethyl, and nitro groups stabilizes the aggregate state.
  • Tohru Koike
    1991 Volume 64 Issue 6 Pages 1726-1730
    Published: 1991
    Released: June 07, 2006
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    The atomic resonance absorptions of O- and H-atoms in the reaction of shock-heated H2/O2/CO/Ar(1/1/1/97 and 0.2/1/1/97.8) mixtures were observed over a relatively low temperature range from 1000 to 1400 K. The induction times, determined from the absorptions, were investigated by means of computer modeling which included a sensitivity test. The rate constant for the important initiation reaction, CO+O2=CO2+O, was evaluated to be k13=1013.1±0.6exp (−196.9±14.9kJ⁄RT) cm3 mol−1 s−1, which may supplement the lack of reported rate constants in the low-temperature region.
  • Keiichi Yokoyama, Hiroshi Kitaike, Takayuki Fueno
    1991 Volume 64 Issue 6 Pages 1731-1737
    Published: 1991
    Released: June 07, 2006
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    Matrix-isolated hydrazoic acid HN3 admixed with NO was photolyzed by a low-pressure mercury discharge lamp. Product analysis based on the FTIR spectroscopy has revealed the formations of NH, N2O, OH, HNO, and HONO as photoproducts. From the comparisons of the amount of HN3 consumed with that of N2O produced, we conclude that the reaction of NH(1Δ) with NO proceeds mainly through the process NH(1Δ)+NO→N2O+H. The quantum yield of N2O is found to be φ1=0.7±0.1. The conclusion is in line with our previous results of the gas phase experiments at room temperature.
  • Keiichi Yokoyama, Yasuo Sakane, Takayuki Fueno
    1991 Volume 64 Issue 6 Pages 1738-1742
    Published: 1991
    Released: June 07, 2006
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    Gaseous mixtures of HNCO and NO diluted in Ar were heated by incident shock waves to about 3500 K to investigate the bimolecular reaction of NH(3Σ) with NO. Ultraviolet emissions from the excited NH(A3II) and OH(A2Σ+) were monitored to determine the rate constants for the ground-state reaction NH(3Σ)+NO→N2+OH(X2II). The branching ratio defined as the rate constant for the formation of OH relative to that for the NH(3Σ) decay was found to be 0.32±0.07 at the shock-wave temperature adopted. An intense spike of chemiluminescence due to OH(A2Σ+→X2II) was observed, a finding which indicates a possible participation of the channel NH(3Σ)+NO→N2+OH(A2Σ+) at high temperatures.
  • Yoshihiro Mitsutsuka, Tomonori Aoyama, Shigeru Ohba, Yoshihiko Saito, ...
    1991 Volume 64 Issue 6 Pages 1743-1749
    Published: 1991
    Released: June 07, 2006
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    The structure of cis-[CoF2(NH3)4]ClO4 has been determined by a single-crystal X-ray diffraction method. Crystals are tetragonal, space group P41 (or P43), a=7.2645(6), c=16.260(2) Å, V=858.1(2) Å3, Z=4,T=297(1) K, final R=0.052 for 970 observed unique reflections. The coordinated F and N atoms could be distinguished unambiguously from each other based on the thermal parameters. The bond distances Co–F and Co–N are 1.828(6)–1.870(5) and 1.924(7)–1.944(7) Å, respectively. The absorption spectra of the single crystals have been examined in the visible and infrared regions with polarized radiation by the use of microspectrophotometers. The 584 nm band (B1) was considered to borrow intensity from some A1 bands through vibronic coupling with some B1 vibrations, and the 504 nm band (A2 & B2) through some A2 and B2 vibrations. Two of the four ammine groups of this cobalt complex were found to give an NH3 rocking frequency (860 cm−1) higher by 50 cm−1 than the other two (at 810 cm−1). This fact has been attributed to two inter-molecular hydrogen bonds (NH···F=2.85–2.68 Å) in which the former two ammine groups are involved.
  • Katsura Mochizuki, Hajime Gotoh, Masaaki Suwabe, Tohru Sakakibara
    1991 Volume 64 Issue 6 Pages 1750-1756
    Published: 1991
    Released: June 07, 2006
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    A new bimacrocyclic ligand, in which 13- and 14-membered rings are linked together by a C–C bond, 6-(1,4,7,10-tetraaza-12-cyclotridecyl)-1,4,8,11-tetraazacyclotetradecane (L13−14), and its dinickel(II) complex, [NiII2L13−14]4+, were synthesized. The absorption spectra and cyclic voltammograms of [NiII2L13−14]4+ showed that it has properties of both the 13- and 14-membered rings. Cyclic voltammetry and controlled-potential electrolysis showed that [NiII2L13−14]4+ can serve as an electrocatalyst for water reduction to produce H2. The electrocatalytic efficiency for H2 produclion at −1.5 V was found to be as follows: [NiII2L14−14]4+ (L14−14: 6,6′-bi(1,4,8,11-tetraazacyclotetradecane))>[NiII2L13−14]4+≈[NiIIL14]2+ (L14: 1,4,8,11 -tetraazacyclotetradecane)>>[NiII2L13−13]4+ (L13−13: 12,12′-bi(1,4,7,10-tetraazacyclotridecane)).
  • Xing-Zheng Wu, Takehiko Kitamori, Norio Teramae, Tsuguo Sawada
    1991 Volume 64 Issue 6 Pages 1757-1762
    Published: 1991
    Released: June 07, 2006
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    Application limits of the proposed concentration depth profile using laser induced fluorescence spectroscopy based on the reciprocal principle (Bull. Chem. Soc. Jpn., 64, 755 (1991)) were investigated. Although this method has no limitations regarding film thickness and spatial resolution in the depth direction theoretically, for practical applications, they are limited by the instrumental factors. Effects of uncertainty in the observation angle measurement, which depends on the size of the detector, the mechanical precision of the rotating stage, and experimental errors in the fluorescence intensity measurement on the accuracy of the reconstructed concentration depth profile were discussed in detail. The theoretical results predicted nanometer level depth profiling with our laboratory-constructed instruments. A 29 nm thick model film sample, consisting of long chain molecular bilayers, was used to verify the theoretical analysis results. The concentration depth profile for bilayer level steps of about 5 nm was obtained under our experimental conditions. Possible improvements in this method and monolayer level depth profiling were also considered.
  • Hajime Kikuchi, Teruaki Suzuki, Etsuro Kurosawa, Minoru Suzuki
    1991 Volume 64 Issue 6 Pages 1763-1775
    Published: 1991
    Released: June 07, 2006
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    A new halogenated C15 nonterpenoid with a novel carbon framework, named notoryne, has been isolated from the title alga and its structure was established on the basis of spectroscopic and chemical evidence. In addition, the structure of a rearranged product, whose structure has long remained unsettled, of laurefucin derivative was also determined by spectral and chemical methods. Furthermore, the biogenesis of the halogenated C15 nonterpenoids from L. nipponica collected at warm current region in Hokkaido is also discussed.
  • Kaoru Harada, Shun-ichiro Igari, Toratane Munegumi, Michiaki Takasaki, ...
    1991 Volume 64 Issue 6 Pages 1776-1781
    Published: 1991
    Released: June 07, 2006
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    Amination of several carboxylic acids by reductive fixation of molecular nitrogen was achieved by glow discharge against aqueous solution of these carboxylic acids. The yield of the aminated product is the highest in the case of maleic acid among carboxylic acids used. The addition of hydrochloric acid to the reaction mixture enhances the yields of aminated products. This may be caused by the fact that chloride anion is oxidized by hydroxyl radicals to chlorate ion, and the fixation of molecular nitrogen proceeds under relatively reducing conditions.
  • Masanori Wada, Mitsuyuki Kanzaki, Masanobu Fujiwara, Kazuhisa Kajihara ...
    1991 Volume 64 Issue 6 Pages 1782-1786
    Published: 1991
    Released: June 07, 2006
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    The title sulfide {2,6-(MeO)2C6H3}3P=S [abbr. (2,6)3P=S] reacted with acids to form a novel mercaptophosphonium salt [(2,6)3P–SH]X, solution thermolysis of which in the absence or presence of triphenylphosphine resulted in the unusual desulfurization to give the tertiary phosphonium salts [(2,6)3P–OH]X. (2,6)3P=S also reacted with alkyl iodides or bromides under mild conditions to give stable (alkylthio)phosphonium salts [(2,6)3P–SR]X (R=Me, Et, n-Bu), which reacted with thiols at room temperature in the presence of a catalytic amount of the tertiary phosphine (2,6)3P to give [(2,6)3P–H]X and unsymmetrical disulfides.
  • Akira Sera, Shoji Fukumoto, Masako Tamura, Kiyoshi Takabatake, Hiroaki ...
    1991 Volume 64 Issue 6 Pages 1787-1791
    Published: 1991
    Released: June 07, 2006
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    The reaction of 1-nitro-2-phenylethenes (β-nitrostyrenes) with aqueous titanium(III) chloride afforded substituted pyrroles in addition to the expected reduction products, oximes and carbonyl compounds. 2-Substituted 1-nitro-2-phenylethenes yielded divinylamine derivatives instead of pyrroles. The reaction mechanism has been rationalized by taking account of the electron transfer from titanium(III) species to the nitro olefins, followed by protonation, dimerization, cyclization, and/or hydrolysis.
  • Keisuke Sugita, Akihisa Ohta, Makoto Onaka, Yusuke Izumi
    1991 Volume 64 Issue 6 Pages 1792-1799
    Published: 1991
    Released: June 07, 2006
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    A new attempt of utilizing solid acids and bases for ring opening of epoxides with Me3SiCN was investigated. Solid strong bases such as calcium oxide and magnesium oxide catalyzed the regio- and chemoselective ring opening of epoxides with Me3SiCN much more effectively than homogeneous catalysts. On CaO and MgO, the reactions of unsymmetrical epoxides with Me3SiCN afforded 3-trimethylsiloxyalkanenitriles in high yields through regio- and stereoselective attack of cyanide ion on the less substituted epoxycarbon. Additionally, on CaO, 2,3-epoxy-1-alkanol derivatives were selectively converted to the corresponding C-3 opened products by the attack of cyanide ion. In these cases no isocyanides were formed. It was suggested that CaO acted as a bifunctional catalyst; the lattice oxide anions of CaO activated Me3SiCN, and simultaneously calcium ions promoted the ring opening of epoxyalkanol as Lewis acid sites.
  • Hiroshi Nishino, Shin-ichi Tategami, Takashi Yamada, James D. Korp, Ka ...
    1991 Volume 64 Issue 6 Pages 1800-1809
    Published: 1991
    Released: June 07, 2006
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    The reactions of 1,1-diphenylethene, 1,1-bis(4-chlorophenyl)ethene, 1,1-bis(4-methoxyphenyl)ethene, 1,1-bis(4-methylphenyl)ethene, 1,1-bis(4-fluorophenyl)ethene, styrene, 1-octene, cyclohexene, and cyclooctene with tris(2,4-pentanedionato)manganese(III) ([Mn(acac)3]) in acetic acid at room temperature give 4-acetyl-3-methyl-1,2-dioxan-3-ol in 8–92% yields, together with 3-acetyl-4-hydroxy-3-hexene-2,5-dione. The similar reactions of 1,1-diphenylethene with 2,4-pentanedione, 3-methyl-2,4-pentanedione, 3-ethyl-2,4-pentanedione, 1-phenyl-1,3-butanedione, acetoacetanilide, and 1,3-cyclohexanedione in the presence of manganese(III) acetate also give the corresponding cyclic peroxide in good to moderate yields. The mechanisms of manganese(III)-induced 1,2-dioxane ring formation and concomitant radical side reaction are discussed.
  • Yukitoshi Fukuda, Seijiro Matsubara, Claude Lambert, Hiroshi Shiragami ...
    1991 Volume 64 Issue 6 Pages 1810-1813
    Published: 1991
    Released: June 07, 2006
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    The reaction of 1-lithio-1-alkynes with oxiranes under the catalytic action of trimethylgallium afforded the corresponding β-hydroxy acetylenic compounds in good yields with excellent regioselectivities. No isomerization of oxiranes was observed during the reactions because of low Lewis acidity of trimethylgallium. The mechanism including activation of an oxirane by the coordination to trimethylgallium was proposed.
  • Masakatsu Yonese, Mikio Yano, Hiroshi Kishimoto
    1991 Volume 64 Issue 6 Pages 1814-1820
    Published: 1991
    Released: June 07, 2006
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    Soluble and insoluble complex formations of gelatin and chondroitin 6-sulfate (Chs-C) were studied by measuring their viscosities and transmittances; the effects of complex formations on H+ ion binding were studied by pH titrations. Soluble complexes were formed electrostatically with low ionic strengths; the compositions of the complexes varied with pH from those of solutions. The weight fraction of Chs-C of the saturated soluble complex was found to be 0.294 at pH=5.1. The composition of the insoluble complexes increased in the fraction of Chs-C with decreasing pH. The compositions were found to agree with the theoretical predictions obtained from the condition of electroneutrality. Furthermore, from pH titrations of mixed solutions comprising gelatin and Chs-C, the apparent dissociation constants, pKa of the carboxylic groups of both polymers were obtained. They were found to increase due to soluble complex formation; soluble complex formation depresses the dissociation of H+ ions due to a shielding of the positively charged amino groups of gelatin.
  • Masaki Yamada, Miki Kimura, Mineyasu Nishizawa, Shigeyasu Kuroda, Ichi ...
    1991 Volume 64 Issue 6 Pages 1821-1827
    Published: 1991
    Released: June 07, 2006
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    The electronic spectra of three types of 1,10-phenanthroline derivatives having different π-conjugated systems, phenanthrolinedione, phenanthrolinone, and the parent phenanthroline, showed characteristic patterns easily distinguished from each other. Analogous spectral patterns were noted in amino-substituted 1,10-phenanthrolines, and the protonated structures of these compounds were characterized on the basis of such spectral features.
  • Kiyoshi Kanamura, Shoji Yoshioka, Zen-ichiro Takehara
    1991 Volume 64 Issue 6 Pages 1828-1834
    Published: 1991
    Released: June 07, 2006
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    The temperature distribution in the tubular solid oxide fuel cell (SOFC) was calculated by using a finite element method. In this study, specially, the heat generation and consumption caused by the entropy changes at anode and cathode were taken into account for the calculation of temperature distribution in SOFC. In order to estimate the tendency of temperature distribution, the current distribution and the partial pressure distributions of hydrogen, steam, and oxygen were obtained from the calculation by using the simple mathematical model. From the temperature distribution in the tubular SOFC, it can be seen that the temperature difference is largest in the region of porous cathode material. This indicates that the heat generation from the entropy change of cathode reaction has the significant effect for the temperature distribution in tubular solid oxide fuel cell.
  • T. Ken Miyamoto, Hikaru Ichida
    1991 Volume 64 Issue 6 Pages 1835-1839
    Published: 1991
    Released: June 07, 2006
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    A series of new dinuclear platinum(II) complexes have been prepared from the reaction of [PtL2(OH)2] with sulfoacetic acid: [PtL2(slac)]2·3H2O, where slac=sulfoacetate dianion; L2=1,2-diaminocyclohexane (1a1c) or 1,2-diaminoethane (2) and L=isopropylamine (3) or ammine (4). They have di-μ-carboxylato bridged dinuclear zwitterionic structures in crystals. Among them, complexes (1a1c) show significant antitumor activities against mice ieukemia L1210.
  • Suzuko Yamazaki-Nishida, Masaru Kimura
    1991 Volume 64 Issue 6 Pages 1840-1845
    Published: 1991
    Released: June 07, 2006
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    The oxidation reaction of the oxalate ion (C2O42−) by the peroxodisulfate ion (S2O82−) is greatly accelerated by irradiation with visible light in an aqueous solution containing tris(2,2′-bipyrazine)ruthenium(II) ([Ru(bpz)3]2+). The mechanism constitutes a chain reaction initiated by a reductive quenching of photoexcited [Ru(bpz)3]2+ with C2O42−. The rate of reaction increases with an increase of the [Ru(bpz)3]2+ concentration or incident light intensity. On the other hand, the reaction rate hardly depends not only on the concentrations of C2O42− and S2O82−, but also on the ionic strength and temperature. The [Ru(bpz)3]2+ acts as a photo-catalyst, although the absorption spectra of the reaction solution are slightly changed during the photoreaction. An analysis of the absorption spectra by a graphic method indicates that another absorbing species than [Ru(bpz)3]2+ is formed in the reaction solution. Such a complex has no photocatalytic effect for the redox reaction between S2O82− and C2O42−. The concentration of the produced complex is always coincident with ca. 0.7% of that of the S2O82− reacted. The reaction mechanism and rate law are clarified to account for the results obtained.
  • Yasushi Kanzaki, Mitsuo Abe
    1991 Volume 64 Issue 6 Pages 1846-1853
    Published: 1991
    Released: June 07, 2006
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    The intercalation of n-alkylamines (carbon number 1–18) into γ-titanium phosphate and γ-zirconium phosphate was examined in aqueous, methanol, and benzene solutions. The interlayer spacings increased with an increase in the carbon number of alkylamines, showing the formation of bilayers of alkylamines in a similar manner to that in previous reports. The intercalation reaction depended on the solvents used to dissolve the alkylamines. For example, an anomaly was observed regarding intercalation in ethanol solutions. The interlayer spacings decreased when the carbon number exceeded 14–16, indicating a distortion or the monolayer formation of alkylamines. The rate of intercalation was also seriously affected by the kind of solvents. Intercalation occurred almost instantaneously in aqueous solutions. The rate of the intercalation reaction was generally faster in benzene solutions than that in ethanol solutions. The formation of bilayers was also more perfect in benzene solutions, and resulting interlayer spacings were slightly larger than those prepared in ethanol solutions. The anomaly in ethanol was attributed to a disturbance due to the cointercalation of methanol molecules. The solvent effect was also accountable due to the dielectric constant, or dipole moment, of solvents.
  • Tomozo Koh, Masako Yajima
    1991 Volume 64 Issue 6 Pages 1854-1858
    Published: 1991
    Released: June 07, 2006
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    The conditions under which tetrathionate is oxidized stoichiometrically to sulfate by iodate have been established by investigating the reaction rate of tetrathionate with iodate in a medium containing varying amounts of sulfuric acid at room temperature and 40 °C. Tetrathionate reacted with iodate with a tetrathionate: iodate mole ratio of 3 : 7 under the conditions of the usual procedure. After a complete reaction, the iodine, formed from excess iodate by the addition of iodide, was spectrophotometrically measured as triiodide. A 14-fold chemical amplification was achieved for the determination of tetrathionate by using the proposed method, compared with the conventional methods via the sulfitolysis and cyanolysis of tetrathionate. A linear calibration graph with a negative slope was obtained over the concentration range 2.5×10−7–2.5×10−5 mol dm−3 tetrathionate (0.5–56 μg of S4O62− in 10 cm3); the relative standard deviation was 0.42% at the 1.5×10−5 mol dm−3 tetrathionate level.
  • Tsutomu Mizuta, Katsuhiko Miyoshi
    1991 Volume 64 Issue 6 Pages 1859-1865
    Published: 1991
    Released: June 07, 2006
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    The crystal structures of the diastereomeric salt pair, Λ-lel3-[Ni(S,S-chxn)3](d-tart)·3H2O (1) and Δ-lel3-[Ni(R,R-chxn)3](d-tart)·5H2O (2) (chxn=trans-1,2-cyclohexanediamine and d-tart=(+)-(R,R)-tartrate dianion), have been determined by single-crystal X-ray diffraction techniques. Crystal 1 is orthorhombic with the space group P212121, a=10.093(2), b=13.589(4), c=22.011(4) Å, and Z=4. Crystal 2 is also orthorhombic with the same space group, a=11.197(2), b=13.102(2), c=22.402(2) Å, and Z=4. In 1, the d-tart ion makes a familiar face-to-face contact with the Λ complex, in which the two alcoholic and one carboxylic O atoms of the d-tart ion are involved in the multiple hydrogen bonds to the three H–N groups on the triangular face of the complex. This contact mode resembles the one found earlier in the chloride d-tart salt of the corresponding Λ Co(III) complex, Λ-lel3-[Co(S,S-chxn)3]Cl(d-tart)·2H2O (3). On the other hand, no such face-to-face contact is present in 2, though it has been found in the corresponding Δ Co(III) complex salt, Δ-lel3-[Co(R,R-chxn)3]Cl(d-tart)·2H2O (4) in which the d-tart ion is obliged to rotate the distal carboxylato group so as to avoid the steric repulsion otherwise imposed on it by one of the bulky chxn ligands. Detailed comparison of the above four crystal structures revealed that the packing modes of the respective complex cations and counterions are surprisingly similar to one another, indicating that the absence of such a face-to-face contact in 2 is attributed to the weaker affinity of the d-tart ion for the divalent Δ Ni(II) complex, rather than to the steric demands of the crystal packing in 2. In 2 are found two deformed contact modes similar to each other, in which the d-tart ion directs its three O atoms to the triangular face, but only one of them is hydrogen-bonded to one or two of the three H–N groups on the triangular face. The d-tart ion thereby avoids the steric repulsion that would be imposed on it if it should make a usual face-to-face contact with the Δ complex.
  • Suzuko Yamazaki-Nishida, Aiko Nagai, Noriko Mouri, Satoko Kawashima, M ...
    1991 Volume 64 Issue 6 Pages 1866-1871
    Published: 1991
    Released: June 07, 2006
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    In the presence of a sacrificial donor (such as ethylenediaminetetraacetic acid, trans-1,2-cyclohexanediaminetetraacetic acid or oxalic acid in a deaerated aqueous solution) [Co(edta)] is reduced to [Co(edta)]2− by quenching oxidatively the photo-excited [Ru(bpy)3]2+ ([Ru(bpy)3]2+*). The reduction rate for the [Co(edta)] increases with an increase in the concentration of the sacrificial donor, and is kept constant at [EDTA] 0.03 mol dm−3, [CDTA] 0.01 mol dm−3, or [C2O42−] 0.07 mol dm−3 at pH 4.6. The ratio [[Co(edta)]]reacted : [EDTA]reacted : [[Co(edta)]2−]formed=2 : 1 : 2 is obtained at pH 5.2. The reaction rates were examined as a function of the concentrations of [Co(edta)] and [Ru(bpy)3]2+ as well as the pH, ionic strength, and temperature of the solution, and the intensity of the incident light. In the presence of oxygen, the decrease of [Co(edta)] is greatly suppressed and the formation of the hydrogen peroxide is appreciable. The reaction mechanism is presented in order to account for the obtained results.
  • Masaru Kimura, Akiko Ohomura, Fumiko Nakazawa, Keiichi Tsukahara
    1991 Volume 64 Issue 6 Pages 1872-1877
    Published: 1991
    Released: June 07, 2006
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    Although the reduction of iodine by diamine-N-polycarboxylate ions such as ethylenediaminetetraacetic acid, trans-1,2-cyclohexanediaminetetraacetic acid, N-(2-hydroxyethyl)ethylenediamine-N,N′,N′-triacetic acid, and ethylenediamine-N,N′-diacetic acid was negligible in the dark, it occurred greatly upon irradiation with visible light of an aqueous solution over the pH range 4–8. The rate of the photo-sensitized reaction was of half-order regarding both the light intensity irradiated and the concentrations of iodine, which correspond to those of the triiodide ion in the presence of excess iodide ions, and was proportional to the concentration of the diamine-N-polycarboxylate ion. Further, the rate was of half-order for concentrations of I below 3×10−4 mol dm−3 and was of inversely half-order for concentrations of I above 6×10−4 mol dm−3. The reaction was inhibited by radical scavengers of acrylonitrile, acrylamide, and hexaamminecobalt(III) ions. Both hydrogen ion and complex forming metal ions, such as copper(II) and zinc(II), are also strong inhibitors of the reaction. The reaction mechanism, where initiation reaction is a photo-dissociation of iodine and the reactive species is a I2\divdot radical anion, is proposed to account for the obtained results.
  • Nagao Kobayashi, Tetsuo Osa
    1991 Volume 64 Issue 6 Pages 1878-1883
    Published: 1991
    Released: June 07, 2006
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    By comparing the induced circular dichroism (ICD) spectrum of 1,4,7,10,13-pentaoxa[13](1,1′)- ferrocenophane, I, in the presence of β-cyclodextrin (β-CDx) with that of ferrocenes (Fcs) in β-CDx or γ-CDx cavity, the disposition of Fcs in the CDxs is determined. Thus, the orientation of Fc in the Fc: β-CDx 1:1 complex and ferrocenecarboxylic acid (FcMA) in β-CDx at pH 2 is considered to be nearly parallel to the molecular axis of β-CDx, while that of Fc in the Fc: γ-CDx 1 : 1 complex, FcMA in β-CDx cavity at pH 9, and FcMA and ferrocenedicarboxylic acid (FcDA) in γ-CDx cavity appears to be close to normal to the molecular axis of the CDx. In addition, based on the ICD spectra, an intense band of Fcs at around 200 nm is assigned as a charge–transfer (CT) transition between the cyclopentadienyl (Cp) rings and iron(II). The advantage of using CDxs for the determination of the polarization direction of absorption bands of chromophore molecules is mentioned in comparison with previous methods.
  • Ying Hu, Mitsunari Uno, Akira Harada, Shigetoshi Takahashi
    1991 Volume 64 Issue 6 Pages 1884-1888
    Published: 1991
    Released: June 07, 2006
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    In the presence of cyclodextrins (CDs), the ring-opening reaction of styrene oxide with NaBH4 in aqueous media proceeded smoothly to give 1-phenylethanol with high selectivity of up to 94%, and kinetic resolution of the racemic epoxide was observed. Kinetic studies suggest the resolution based on the different reaction rates between two enantiomers included in the CD’s cavity. The reaction of epoxides such as 1,2-epoxyindan and 1,2-epoxy-3-phenylpropane are also affected by the addition of CDs to proceed smoothly with high regioselectivities.
  • Kunio Mochida, Masanobu Wakasa, Yoshio Sakaguchi, Hisaharu Hayashi
    1991 Volume 64 Issue 6 Pages 1889-1895
    Published: 1991
    Released: June 07, 2006
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    The photochemical reactions of aryl-substituted digermanes were investigated by trapping experiments and a laser flash photolysis technique. The photolysis of phenylated digermanes resulted in germanium–germanium bond homolysis to give a pair of two germyl radicals. The germyl radicals abstracted a chlorine atom from carbon tetrachloride to give chlorogermanes. The pair of germyl radicals also underwent ipso-substitution, which was a precursor of the germylenes. The mechanism for the photochemistry of phenylated digermanes is discussed.
  • Takashi Arimura, Seiji Shinkai
    1991 Volume 64 Issue 6 Pages 1896-1900
    Published: 1991
    Released: June 07, 2006
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    Calix[n]arenes (n=4 and 6) bearing (S)-5-oxo-2-pyrrolidinylcarbonyloxyl groups on the lower rim were synthesized. In chloroform, the hexamer bearing six (S)-5-oxo-2-pyrrolidinylcarbonyloxyl groups could “bind” ferrocenecarboxylic acid through hydrogen-bonding interactions, the complexation being conveniently detected by induced circular dichroism (ICD) spectroscopy (λmax 445 nm). On the basis of the examination of acyclic reference compounds, the appearance of the ICD band was explained as such that one pyrrolidone unit acts as a binding site and the chiral center in the neighboring pyrrolidone unit affects the transition moments in the ferrocene π-system. The association constant for the 1 : 1 complex was estimated to be 680 M−1. This is a new, convenient method for detecting the formation of molecular complexes with calixarenes in organic media.
  • Takehiko Goto, Shin Utsunomiya, Hiroshi Aiba, Hirotaka Hayasaka, Mikih ...
    1991 Volume 64 Issue 6 Pages 1901-1910
    Published: 1991
    Released: June 07, 2006
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    Various 7-substituted 6,7-dihydro-5H-pyrrolo[3,4-b]pyridin-5-ones are synthesized by the reaction of the corresponding 7-hydroxy derivatives with nucleophiles involving active methylene compounds, aromatics, alcohols, p-toluenethiol, benzenesulfinic acid, triethyl phosphite, ammonia, and amines under acidic or basic conditions. Some synthetic applications of the products obtained are demonstrated to give a 7-methylene derivative and fused tricyclic derivatives.
  • Po-Chung Cheng, Tsutomu Nonaka, Tse-Chuan Chou
    1991 Volume 64 Issue 6 Pages 1911-1915
    Published: 1991
    Released: June 07, 2006
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    A mathematical mechanism model is developed for the electroreduction of carbonyl compounds in an acidic solution and shows that the formation ratio of hydrodimeric to hydromonomeric products, i.e. the product-selectivity, depends on substrate concentration, mass transfer coefficient and current density. Model calculations are in agreement with experimental results from the electroreduction of p-methylbenzaldehyde using a rotating cylinder cathode and explain a drastic effect of mass transport on the product-selectivity.
  • Subhasis Chakrabarti, Tridibendra Marayan Misra, Mahesh Kumar Sarma, K ...
    1991 Volume 64 Issue 6 Pages 1916-1919
    Published: 1991
    Released: June 07, 2006
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    Raman phonon spectroscopy in the 10–170 cm−1 range has been used to study phase transition in 4-cyanopyridine crystal. At 77 K, ten distinct phonon modes and an internal mode are observed whereas at 300 K the spectrum shows only six phonon bands and an internal mode. The temperature dependence of spectral pattern and phonon band width suggest that the crystal goes through a phase transition around 120 K. Experimental result suggests that the phase transition is discontinuous with a small structural change.
  • Kuzhunellil Raghavan Pillai Sabu, Kalur Vijayachandra C. Rao, Chandrat ...
    1991 Volume 64 Issue 6 Pages 1920-1925
    Published: 1991
    Released: June 07, 2006
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    Investigations are carried out to have a systematic comparison of the acidic properties and catalytic activities of single oxide TiO2, SiO2, Al2O3, their binary oxides and the ternary oxide TiO2–SiO2–Al2O3. The acidity distributions are measured by using butylamine titration technique and the test reactions selected for the catalytic activity measurements are alkylation of toluene with 2-propanol and the dehydration of 2-propanol. The single oxides have only low acid strength and are not at all active in catalyzing the alkylation reaction, but are marginally active in the dehydration of 2-propanol. However the binary oxides SiO2–TiO2 and Al2O3–TiO2 of 10% by weight of TiO2 are found to contain very strong acid sites Ho−8.2 and are highly active catalysts in both the test reactions. But TiO2–SiO2–Al2O3 of 10% by weight of TiO2 showed the highest acid amount and the highest activity in the aikylation and dehydration reactions compared to the binary oxides. The acid amount and the catalytic activity of the ternary oxide increased with the increase of TiO2 content upto 50 mol% of TiO2 and then decreased. The ternary oxide containing 80 mol% of TiO2 is rich in weak acid sites. The increase of TiO2 content does not affect the selectivity.
  • Kuzhunellil Raghavan Pillai Sabu, Kalur Vijayachandra C. Rao, Chandrat ...
    1991 Volume 64 Issue 6 Pages 1926-1932
    Published: 1991
    Released: June 07, 2006
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    The ternary oxide system MoO3–SiO2–Al2O3 was prepared by coprecipitation method. The pH of coprecipitation has been varied from pH=2 to pH=8 and its effect on the acidic properties of the ternary oxide acidic system was studied by butylamine titration. The MoO3–SiO2–Al2O3 prepared from highly acidic solution has low acid strength. The total acid amount of the ternary oxide decreased considerably at higher pH (>6) of coprecipitation. It was found that the total acid amount of MoO3–SiO2–Al2O3 containing 9.7% (by weight) of MoO3 and silica to alumina molar ratio 16.6 is very high compared with that of SiO2–Al2O3 of the same silica to alumina molar ratio. The acid strength of SiO2–Al2O3 is reduced by the incorporation of MoO3. Increase in calcination temperature increased the acid strength. The catalytic activity of MoO3–SiO2–Al2O3 was found to be very high for the alkylation of toluene with 2-propanol. The products are found to be o-cymene, p-cymene, and three isomers of diisopropyltoluenes. Reaction temperature >200°C, higher liquid hourly space velocity, and higher alcohol content in the feed decreased the total conversion of 2-propanol to isopropyltoluenes. The acidic property and catalytic activity of MoO3–SiO2–Al2O3 are not considerably reduced up to four successive regeneration cycles.
  • Pichai Maruthamuthu, Karuppusamy Gurunathan, Esaikkiappan Subramanian, ...
    1991 Volume 64 Issue 6 Pages 1933-1937
    Published: 1991
    Released: June 07, 2006
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    Bi2O3 semiconductor powder (Eg=2.8–2.9 eV) was chosen for the first time to effect photocatalysis and was found to decompose peroxomonosulfate (PMS) with visible light of λ>400 nm. Doping of Bi2O3 with Cu(II)-ion considerably enhanced the photocatalytic efficiency. The effects of variation of (i) the [dopant] in Cu(II)/Bi2O3, (ii) the catalyst amount, and (iii) the initial [PMS] on the rate of decomposition of PMS were investigated. It was observed that (a) 4 atomic % was the optimum [dopant] for Cu(II)/Bi2C3, (b) the rate increased linearly with increase in catalyst amount, and (c) the decomposition of PMS followed a Langmuir kinetics in the concentration range, [PMS]0=0.5–3.0×10−3 mol dm−3. A suitable reaction mechanism is proposed for the decomposition of PMS involving all the possible reactions. A comparative analysis of the photocatalytic activities of undoped and Cu(II)-doped Bi2O3, WO3, and Fe2O3 indicated that Cu(II)-doping enhances the activity of Bi2O3 to a greater extent than those observed with the other two semiconductors. This photocatalytic decomposition of PMS is one of the examples of visible light assisted reaction which otherwise takes place under UV radiation (λ280 nm) only.
  • Ram Adhar Singh, Ranjana Singh, Shiva Mohan Verma
    1991 Volume 64 Issue 6 Pages 1938-1943
    Published: 1991
    Released: June 07, 2006
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    The synthesis, chemical and structural characterizations, and thermal, spectral, electrical, and magnetic properties of six molecular semiconductors based on the charge transfer complexes of substituted phenothiazines namely; phenothiazine, 2-chlorophenothiazine, 2-(trifluoromethyl)phenothiazine, 2-acetylphenothiazine, N-acetylphenothiazine, and N-benzoylphenothiazine with molecular iodine have been reported in this paper. These complexes have been found to have 2 : 3 stoichiometries. X-Ray diffraction data show that first three complexes have orthorhombic structure whereas the other three are amorphous. Thermal analysis shows that the complexes are thermally stable upto 120 °C. The existence of monomeric and dimeric cationic species of phenothiazines has been proposed on the basis of spectral data. These complexes have been found to be molecular semiconductors having moderately high electrical conductivities and activation energies. The segregated stacking of phenothiazine and iodine moieties has been proposed to be responsible for high conductivity values and a mixed conductivity mechanism accounts for temperature dependence of electrical conductivities of these complexes.
  • Kanak Chandra Medhi
    1991 Volume 64 Issue 6 Pages 1944-1950
    Published: 1991
    Released: June 07, 2006
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    The infrared spectra in the polycrystalline state (4000–50 cm−1), in melt and in solution and the Raman spectra in the solid state and in melt of the substances have been studied for 2-pyridone and 2-pyridone-N-d. A vibrational assignment of the observed frequencies is given. Ideal gas state thermodynamic functions of the two isotopic molecules based on the observed fundamental frequencies have been determined in the temperature range 200–1500 K.
  • Ganesh Shantilal Desai, Vijay Malhar Shinde
    1991 Volume 64 Issue 6 Pages 1951-1954
    Published: 1991
    Released: June 07, 2006
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    A method has been proposed for the extraction of bismuth(III) at microgram level from bromide media using mesityl oxide as an extractant. The bismuth–bromo complex formed in the concentration range of 0.05–0.3 mol dm−3 hydrobromic acid showed quantitative extraction into mesityl oxide. Various experimental conditions such as acid concentration, mesityl oxide concentration, period of equilibration, stripping agents, and diverse ions have been studied. Bismuth ion after stripping is determined by thiourea spectrophotometrically. The method is applicable to the analysis of pharmaceutical samples, alloy samples, and synthetic mixtures.
  • Ashu Rani, D. S. N. Prasad, Rachna Bhargava, Krishna Swarup Gupta
    1991 Volume 64 Issue 6 Pages 1955-1961
    Published: 1991
    Released: June 07, 2006
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    Autoxidation of S(IV), in buffered solutions,conforms the rate law (1). The increase in buffer concentration has a
    Robsd=k5[CdO][S(IV)]2[H+]−1.22 (1)
    rate decreasing effect. On the other hand, in unbuffered solutions the kinetics obey a different rate law (2).
    Robsd=(k10+k11[CdO])[S(IV)][H+]−0.5 (2)
    In both situations, the dissolution of CdO accompanies the autoxidation. A heterogeneous catalytic mechanism involving adsorption of both dioxygen and sulfur(IV) on the surface of CdO particle has been proposed.
  • N. V. Deorkar, Shnpad M. Khopkar
    1991 Volume 64 Issue 6 Pages 1962-1965
    Published: 1991
    Released: June 07, 2006
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    Scandium was quantitatively extracted at pH 2.5–4.5 with 4.0×10−2 mol dm−3 18-crown-6 in dichloromethane from 4.0×10−2 mol dm−3 solution of picric acid. It was stripped with 0.1 mol dm−3 nitric acid and determined spectrophotometrically at 650 nm as its complex with Arsenazo-III. It was separated from yttrium, lanthanides, zirconium, hafnium, vanadium, niobium, and uranium in multicomponent mixtures. Scandium from rock sample was also analysed.
  • Ahmed M. Nour El-Din, Aboul-Fetouh E. Mourad, Alaa A. Hassan, Mohsen A ...
    1991 Volume 64 Issue 6 Pages 1966-1970
    Published: 1991
    Released: June 07, 2006
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    N-(4-Dimethylaminobenzylidene)anilines and N1-(4-dimethylaminophenyl)-N1,N2-diphenylformamidine reacted with tetrachloro-, tetrabromo,- and tetrafluoro-p-benzoquinones via charge-transfer complexes formation giving 2-monoarylamino-3,5,6-trihalo-p-benzoquinones and 2,5-bis(arylamino)-3,6-dihalo-p-benzoquinones. The course of the reaction leading to the formation of the products has been interpreted.
  • Ingeborg Csöregh, Stephan Finge, Edwin Weber
    1991 Volume 64 Issue 6 Pages 1971-1975
    Published: 1991
    Released: June 07, 2006
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    The crystal structures of two inclusion complexes between anti-N-N′-di-t-butyl-9,10-dihydro-9,10-ethanoanthracene-11,12-dicarboxamide host and methanol [a=11.8893(4), b=18.0943(7), c=12.6322(4) Å, β=108.47(3)°, P21c, Z=4] or propionic acid [a=11.4580(8), b=11.7614(9), c=12.4675(8) Å, α=95.37(3), β=109.70(3), γ=113.26(3)°, P\bar1, Z=2] as guests have been studied by X-ray diffraction. Closed loops of different sizes, formed via hydrogen-bond interactions between host and guest or between the hosts only, characterize both structures. The crystals with the propionic acid guest consist of hydrogen-bonded host : guest associates with 2 : 2 stoichiometry, while the methanol inclusion gives rise to infinite hydrogen-bonded chains.
  • Toshihiko Ozawa, Akira Hanaki
    1991 Volume 64 Issue 6 Pages 1976-1978
    Published: 1991
    Released: June 07, 2006
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    The selenite radical anion, SeO3\divdot, can be detected by ESR spectroscopy using water-soluble spin-traps, N-(4-pyridylmethylene)-t-butylamine N,N′-dioxide (POBN) and 3,5-dibromo-4-nitrosobenzenesulfonate (DBNBS), but selenate radical anion, SeO4\divdot, cannot be trapped by POBN or DBNBS.
  • Tatsuyoshi Takuma, Toshio Deguchi, Isao Sanemasa
    1991 Volume 64 Issue 6 Pages 1979-1981
    Published: 1991
    Released: June 07, 2006
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    The complex formation of α- and β-cyclodextrins (CyDs) with p-(chloro, bromo, and iodo)fluorobenzenes has been studied in aqueous medium at 25°C. Formation constants are compared with those of CyD–monohalobenzene systems.
  • Hu Huang, Fumiaki Kai, Chiemi Uragami, Masaaki Hirohata, Hiroaki Chiku ...
    1991 Volume 64 Issue 6 Pages 1982-1984
    Published: 1991
    Released: June 07, 2006
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    New ligands, 1-(3,5-dichloro-2-pyridyl-azo)-2-naphthol, 2-(3,5-dichloro-2-pyridyl-azo)-5-(dimethylamino) phenol, and 2-(3,5-dichloro-2-pyridyl-azo)-5-(dimethylamino)benzoic acid, were synthesized. Changes in the reduction potentials and electronic spectra of the ligands upon complexation with Ni(II), Zn(II), and Cd(II) were studied. The dissociation constants of the ligands and the stability constants of their metal(II) complexes are discussed.
  • Akira Tatehata, Hiromi Akita
    1991 Volume 64 Issue 6 Pages 1985-1987
    Published: 1991
    Released: June 07, 2006
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    The stereoselectivities in the oxidation of [Co(en)3]2+ by chiral cobalt(III) complexes containing six-membered chelate ligands, such as malonate, β-alaninate, and acetylacetonate ions, were examined. All of the oxidant complexes with the Δ-configuration studied here, like the corresponding oxalato and glycinato complexes containing five-membered chelate rings, led to an excess of Λ-[Co(en)3]3+, with the exception of Δ-[Co(ox)(acac)2].
  • Masafumi Mizuno, Shigenobu Funahashi, Noriyuki Nakasuka, Motoharu Tana ...
    1991 Volume 64 Issue 6 Pages 1988-1990
    Published: 1991
    Released: June 07, 2006
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    Activation parameters for solvent exchange of the title complex in N,N-dimethylformamide (DMF) have been determined as follows: k(25°C)=(3.4±0.2)×107 s−1, ΔH\ eweq=18±3 kJ−1 mol−1, ΔS\ eweq=−40±10 J K−1 mol−1, and ΔV\ eweq=10±2 cm3 mol−1. The positive value of ΔV\ eweq indicates that the DMF exchange proceeds via a dissociative interchange mechanism.
  • Tamio Kamidate, Tetsutoshi Kaneyasu, Tadashi Segawa, Hiroto Watanabe
    1991 Volume 64 Issue 6 Pages 1991-1992
    Published: 1991
    Released: June 07, 2006
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    A remarkable lowering of chemiluminescence (CL) emitted from the CL reaction of lucigenin (Luc) with adrenaline (AD) was observed in cationic micellar assemblies containing halide ions, when their concentrations were above 5×10−3 mol dm−3. These results could be explained in terms of the quenching of the Luc CL reaction by halide ions. The quenching by chloride ions was dependent on the carbon number in the alkyl group of surfactant reagents.
  • Shinsei Sayama, Yutaka Inamura
    1991 Volume 64 Issue 6 Pages 1993-1995
    Published: 1991
    Released: June 07, 2006
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    The epoxidation of 1,4-disubstituted 2-butene-1,4-diones with 30% aq H2O2 in the presence of a catalytic amount of quaternary ammonium iodide afforded 2,3-epoxy-1,4-butanediones in high yield.
  • Sadao Arai, Norikazu Nakamura, Hiromichi Yamaguchi, Masa-aki Okazaki, ...
    1991 Volume 64 Issue 6 Pages 1996-1998
    Published: 1991
    Released: June 07, 2006
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    The 2-styrylbenzo[a]quinolizinium salt was photocyclized to afford 12a-azoniabenzo[ghi]perylene salt in 66% yield. The 2a-azoniabenzo[a]coronene salt was obtained by the photocyclization of 2-[2-(4-biphenylyl)vinyl]benzo[a]-quinolizinium salt and 2-styryl-10-phenylbenzo[a]quinolizinium salt in 80% and 75% yields, respectively.
  • Tatsuo Ishiyama, Norio Miyaura, Akira Suzuki
    1991 Volume 64 Issue 6 Pages 1999-2001
    Published: 1991
    Released: June 07, 2006
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    The synthesis of α,β-unsaturated ketones by means of the palladium-catalyzed cross-coupling reaction between 9-alkyl-9-borabicyclo[3.3.1]nonanes (9-R-9-BBN) and 1-halo-1-alkenes under carbon monoxide atmosphere is described.
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