Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
67 巻 , 10 号
選択された号の論文の49件中1~49を表示しています
  • Gamal K. Gomma, Mostafa H. Wahdan
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 10 号 p. 2621-2626
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    The inhibition of steel corrosion in 0.5 M sulfuric acid by adenine at different temperatures was shown to follow the Langmuir adsorption isotherm over a wide concentration range (10−5 to 10−3 M). The corrosion potential, corrosion current, corrosion rate, polarization resistance, as well as activation energy and thermodynamic parameters were calculated at different temperatures. From a comparison of the activation energies of uninhibited and inhibited corrosion reactions, the heat of adsorption of adenine may be obtained. The temperature coefficient for corrosion inhibition has a negative value, which may be explained by assuming that the corrosion reaction is no longer the simple metal/acid reaction, but involves the adsorbed species directly.
  • Taku Nakano, Yoshihiro Mori
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 10 号 p. 2627-2633
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    Irradiation of visible light on a dichloromethane or chloroform solution in the presence of halogenated p-benzoquinones, such as fluoranil, chloranil, and bromanil, caused the formation of an acid, HCl. In the presence of octaethylporphyrin in those solutions, the photoinduced protonations of porphyrins were observed. Stepwise spectral changes suggested the formations of monocationic and dicationic species and an “intermediate” which had a spectrum with maximum wavelength at 717 nm. The unstable intermediate was suggested to be octaethylphlorin. But the trial to isolate the intermediate gave octaethylbilindione. Dioxygen was found to exert both negative and positive effects on the acidification of solvents and on the protonation on porphyrin in the octaethylporphyrin–bromanil systems. The mechanisms of these photochemically induced reactions are discussed.
  • Gamal Abdel-Halim Mohamed Hussein, Hamdy Mahmoud Ismail
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 10 号 p. 2634-2638
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    Nd2O3 catalyst was obtained as a final product of the thermal decomposition of Nd(CH3COO)3·2H2O. The decomposition processes up to 800 °C were characterized by means of TG, DTA, XRD, and IR spectroscopy of the gas and solid phase products. The activation energy values were determined non-isothermally for thermal events involved in the decomposition course. The results indicate that Nd(AcO)3 is completely decomposed to Nd2O3 at 670 °C through five different intermediates; Nd(OH)(CH3COO)2 at 310 °C, NdO(CH3COO) at 320 °C, Nd2(CO3)3 at 350 °C, Nd2O(CO3)2 at 385 °C, and Nd2O2(CO3) at 410 °C. The oxide, Nd2O3, obtained at 800 °C possesses higher surface area (30 m2 g−1) than that obtained at 1000 °C (10 m2 g−1).
    Thus, the oxide obtained at 800 °C was tested qualitatively and quantitatively as a catalyst towards the decomposition of 2-propanol at 100—400 °C by IR-spectroscopy. The results indicate that Nd2O3 catalyses 2-propanol dehydrogenation (forming acetone) at < 300 °C and dehydration (forming propene) at > 250 °C. At > 350°C, acetone was involved in a secondary surface reaction, presumably with the surface hydroxyl groups, to give CH4 and CO2 in the gas phase.
  • Karuppiah Pandiarajan, Senthamaraikannan Kabilan, Punnaivanam Sankar, ...
    1994 年 67 巻 10 号 p. 2639-2646
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    13C, 15N, and 17O NMR spectra have been recorded for 4-nitroanisole (1), its 2-methyl-, 2-chloro-, 2-bromo-, 2-iodo-, 2,6-dimethyl-, 2,6-dichloro-, 2,6-dibromo-, and 2,6-diiodo-derivatives 29, also nitrobenzene (1a), its 3-methyl-, 3-chloro-, 3-bromo-, and 3-iodo-derivatives 2a5a and 3,5-dichloro- and 3,5-dibromo-derivatives 7a and 8a. Analysis of the chemical shifts of carbon bearing nitro group and nitro oxygens in these compounds suggests that presence of one substituent ortho- to the methoxyl group enhances its resonance interaction with the benzene ring whereas presence of two ortho-substituents inhibits this resonance. However, in no case the resonance is completely inhibited. The extent of enhancement or inhibition is almost independent of the nature of the ortho-substituent. This conclusion has also been arrived by analyzing the reported chemical shifts of the para-carbons in anisoles 1b9b and the corresponding carbons in benzene derivatives 1c9c. Though evidence could not be obtained for steric enhancement of resonance using methoxyl oxygen chemical shifts, analysis of these chemical shifts in di-ortho-substituted anisoles 69 and 6a furnishes evidence for steric inhibition of resonance. However, 15N chemical shifts are of no use in studying these phenomena. Semiempirical molecular orbital calculations using AM1 Hamiltonian suggest that the methoxyl group is coplanar with the benzene ring in anisole, 4-nitroanisole and 2-substituted-4-nitroanisoles but is perpendicular to the benzene ring in 2,6-disubstituted-4-nitroanisoles. Moreover, in 2-substituted-4-nitroanisoles the O-methyl group is anti to the 2-substituent.
  • Kiyofumi Murakami, Miki Akamatsu, Takayuki Sano
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 10 号 p. 2647-2653
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    The binding of 11 azo and pyrene dyes (which have 1 to 4 sulfonato groups) to bovine serum albumin at pH = 7.0 and 25 °C has been studied by spectrophotometry, equilibrium dialysis, and/or ultrafiltration method. Binding parameters were determined assuming one or two classes of independent binding sites. By combining with data reported before, we examined the effects of hydrophobicity and net charge number of ligands on the binding parameters for a total of 19 dyes. The ratio of the binding ability to the primary sites to the total binding ability, a measure of binding specificity, was found to increase with an increase in the anionic charge number of ligands. The values of binding constant for nonspecific binding of the monoanionic dyes and for the primary binding of the multicharged dyes were found to have a strong correlation to both the hydrophobicity and the anionic charge number of ligands. A multiple regression analysis has derived the equation:

    where K is a binding constant, P is the partition coefficient in 1-octanol/water system, and m and αi are respectively the number of anionic groups and the degree of dissociation of the i-th group. From this equation, the contribution of electrostatic interactions due to a unit net charge on ligands to the standard free energy change of binding was estimated to be −11.4 kJ mol−1. The role of electrostatic interactions has been discussed in detail.
  • Taro Suzuki, Kazuyuki Horie, Takashi Yamashita, Masami Bitoh, Satoshi ...
    1994 年 67 巻 10 号 p. 2654-2658
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    Glycosides of tetraphenylporphine were synthesized and studied by photochemical hole burning (PHB) spectroscopy. The derivatives with lactosyl groups in poly(vinyl alcohol) (PVA) shows excellent thermal stability against cyclic annealing, which is superior to that of sulfonated tetraphenylporphine (TPPS) in PVA. It is supposed that the hydroxyl groups of the glycosides as well as those of PVA would contribute to reducing irreversible structural relaxation by forming hydrogen bonds.
  • Kiyohiko Someda, Hiroki Nakamura
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 10 号 p. 2659-2664
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    A model triatomic reaction Cl + Cl2 → Cl2 + Cl embedded in an Ar52 van der Waals cluster is analyzed classical mechanically by a novel theoretical method called “decoupling surface analysis”. This method generates new reactive and vibrational variables in which the kinetic coupling as well as the potential coupling are minimized. An analysis of local frequencies of the vibrational variables along the reaction coordinate clarifies how the motions of ambient Ar atoms are coupled with the central Cl3 system. When the local frequencies are plotted as a function of the reaction coordinate, avoided crossings among these curves are observed. Mixing of Cl motion and Ar motion is clearly detected by these avoided crossings. The vibrational mode having a character of the symmetric stretch of Cl3 shows exclusively strong coupling with the reactive motion. This mode, however, very weakly couples with the ambient Ar motion. On the other hand, the bending and translation of Cl3 are strongly mixed with the motions of ambient Ar atoms and produce unstable modes, which play the most significant role in energy exchange between the central reaction system and the ambient Ar atoms.
  • Kazuhiro Kanda, Kaoru Suzuki, Haruhiko Ito, Tamotsu Kondow, Kozo Kuchi ...
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 10 号 p. 2665-2668
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    The CN(B2Σ+–X2Σ+) emission spectrum produced in the reaction of Ar(3P2) with BrCN was observed by the use of a flowing afterglow method at argon pressures ranging from 9 mTorr to 2 Torr (1 Torr = 133.322 Pa). The pressure dependences of the intensity anomalies in the rotational lines due to the B2Σ+∼A2Πi and the B2Σ+4Σ+ perturbations were measured by introducing collision-partner gases in the reaction region. These pressure dependences can be explained by the “doorway” model. On the other hand, the measured pressure dependence of the effective rotational temperature in the CN(B2Σ+) state can also be reproduced by the collision-induced rotational relaxation model. The cross section for the rotational relaxation in the A2Πi state was found to be smaller than those in the B2Σ+ and 4Σ+ states. This finding is interpreted by the use of the dipole–induced dipole interaction model for the collision–induced rotational relaxation.
  • Teruhisa Komura, Naoki Kitani, Koshin Takahashi
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 10 号 p. 2669-2674
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    The effect of electrode potential and film thickness on the kinetic parameters of the oxidation process of polythiophene (PT) was investigated by an a.c. impedance method and conductivity measurements. The conductivity of a PT film increased with its oxidation and reached a limiting value at higher potentials than 0.8 V despite a rise in oxidation state of PT. The oxidation of the PT film lowered the activation energy of electric conduction, which suggested the broadening of a polaron band. An increase in the oxidized form of thiophene unit brings about the decrease in charge transfer resistance at the polymer electrode in the lower potential range than the half-wave potential of PT. Both the redox capacitance of the polymer and d.c. resistance associated with the diffusion of a charge carrier indicated the dependence on the potential and film thickness which was expected from a finite diffusion model. A large capacitance of the order of 1—30 mF cm−2 in the oxidized state is explained in terms of the charge saturation effect due to the finite thickness and porous nature of the polymer film.
  • Yoshiharu Usui, Naomi Tanaka, Masao Yoshida, Yasufumi Asai, Masatoshi ...
    1994 年 67 巻 10 号 p. 2675-2678
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    Absorption of visible light by acridine orange (AOH+) brought about the photoaddition of CCl4 to the excited singlet of anthracene derivatives, (1A*), which occurred by the direct excitation with UV light. From the dependence of the quantum yields on the concentrations of CCl4 and A and on the light intensity in ethanol solution, a mechanism involving the triplet energy transfer from 3AOH+ to A and the annihilation of 3A to form 1A* is proposed.
  • Kazuhiko Honda, Kazuo Kitaura, Kichisuke Nishimoto
    1994 年 67 巻 10 号 p. 2679-2684
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    Monte Carlo (MC) simulation was done for liquid ammonia using the potential function expressed by the intermolecular overlap integrals and fractional point charges on the atoms. Thermodynamic properties were estimated using a partition function whose parameters are obtained by referring the results of the MC simulation. The calculated thermodynamic properties were examined by the physically meaningful interaction terms. A comparative study with NH3, H2O, and HF was done and a new index proposed to characterize the liquid with hydrogen bondings.
  • Takehiko Mori, Yohji Misaki, Hideki Fujiwara, Tokio Yamabe
    1994 年 67 巻 10 号 p. 2685-2689
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    The ClO4, BF4, and ReO4 salts of BDT-TTP, 2,5-bis(1,3-dithiol-2-ylidene)-1,3,4,6-tetrathiapentalene, are isostructural, having uniform columns of the donor molecules. These salts are essentially metallic down to low temperatures, though the resistivity increases to some extent below 200 K. The thermoelectric power and ESR show simple metal-like behavior down to low temperatures.
  • Hirochika Naganawa, Shoichi Tachimori
    1994 年 67 巻 10 号 p. 2690-2699
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    The hydration and ionization of nitric acid in benzene were examined at 298 K. The distribution of nitric acid and of water between aqueous solutions and benzene were determined as functions of water activity in the aqueous phase. Two hydrates, mono- and decahydrate, were found in addition to the anhydride in the organic phase by analyzing the distribution data on the basis of the stoichiometry of the acid hydration. The mono- and decahydrate were ascribed to molecular and ionized nitric acid, respectively, by means of spectrophotometry of the organic phase. By the analyses of the absorption spectra and the distribution data, the ionization of nitric acid by water in benzene was clarified and the equilibrium constant was determined.
  • Tatsuya Sekine, Thi Kim Dung Nguyen
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 10 号 p. 2700-2706
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    The solvent extraction of iron(II) in aqueous 0.1 mol dm−3 sodium nitrate solutions containing ascorbic acid with benzoyltrifluoroacetone (Hbfa) into carbon tetrachloride was studied in the absence and presence of tetrabutylammonium ion (tba+) or trioctylphosphine oxide (TOPO). By the addition of tba+, the tba+Fe(bfa)3 species, and by the addition of TOPO, the Fe(bfa)2TOPOn (n = 1 or 2) species were extracted in addition to the Fe(bfa)2 species and the extraction was greatly enhanced. The iron(II) in the benzoyltrifluoroacetonate complex extracted in the organic phase was oxidized rather quickly and the rate of this oxidation was also studied. An addition of tba+ or TOPO to the system slowed down the oxidation reaction, and the reason for the effects of tba+ and TOPO on the rate of oxidation is discussed.
  • Masatomi Sakamoto, Koji Yamamoto, Akira Matsumoto, Yuzo Nishida, Hisas ...
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 10 号 p. 2707-2711
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    Fluorescence spectra of europium(III) and terbium(III) have been measured in methanolic solutions containing various amounts of [M(salen)] (M = Cu(II), Ni(II)), [Cr(salen)(H2O)2]Cl, [M(saltn)] (M = Cu(II), Ni(II)), [Cu(acacen)], [M(acac)2] (M = Cu(II), VIVO), [M(acac)3] (M = Cr(III), Co(III)), or [Ni(acac)2(H2O)2]. Our purpose was to investigate the influence of these metal complexes on the fluorescence of Eu(III) and Tb(III), where H2salen, H2saltn, H2acacen, and Hacac stand for N,N′ -bis(salicylidene)ethylenediamine, N,N′-bis(salicylidene)-1,3-propanediamine, N,N′ -bis(1-methyl-3-oxobutylidene)ethylenediamine, and acetylacetone, respectively. The fluorescence intensities of both Eu(III) and Tb(III) decreased with increasing the concentration of [M(salen)] (M = Cu, Ni), [Cr(salen)(H2O)2]Cl, [M(saltn)] (M = Cu, Ni), [Cu(acacen)], and [M(acac)3] (M = Cr, Co), whereas it was little affected by simple metal salts. The intensity of Tb(III) increased up to the addition of a given amount of [M(acac)2] (M = Cu, VO) or [Ni(acac)2(H2O)2] and then decreased on further addition, whereas the intensity of Eu(III) decreased gradually by the addition of these acetylacetonate complexes. These results are explained by the formation of heteronuclear complex species and by the stabilities of acetylacetonate complexes.
  • Masanao Kato, Toshiaki Hattori, Tsuyoshi Suzuki, Kazuo Tsutsumi
    1994 年 67 巻 10 号 p. 2712-2715
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    Distributions of acetylacetone and its copper complex between an aqueous phase and a chemically modified silica gel were measured. The modified silica gels were synthesized, and four different alkyl chains from butyl to octadecyl groups were introduced into the surface. The observed distributions were interpreted by a solubility parameter theory as in a liquid-liquid partition experiment. It is found that the solubility parameter theory can be used as a tool for interpretation of the distribution of acetylacetone and its complex between aqueous and gel phases.
  • Garbine Guiu, Paul Grange
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 10 号 p. 2716-2723
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    Mixed oxides, especially silica containing multicomponent oxides, have recently found many applications in the production of glasses, ceramics and catalysts. This paper reports for the first time the synthesis of SiO2–Ta2O5 mixed oxide by the sol–gel method. The advantage of the sol–gel method is that a relatively large concentration of tantalum can be incorporated in the mixed oxide structure. Physicochemical characterization shows that tantalum atoms are incorporated into the silica matrix producing Si–O–Ta bonds.
  • Yasuyoshi Mori, Hiroshi Yokoi
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 10 号 p. 2724-2730
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    The interaction between iron(III) and glycerol or related polyols was studied in some detail over a pH range of 1 to 13 mainly by spectrophotometric and NMR measurements. At acidic pH, there appeared a new absorption band at 350 nm in the difference spectra of iron(III) before and after the addition of glycerol, showing that iron(III) and glycerol form a 1 : 1 complex. Although the 13C NMR relaxation rates for all of the carbon atoms of glycerol and 1,3-propanediol were markedly affected by the addition of iron(III), the rate for C-2 of 1,4-butanediol remained unchanged. These facts indicate that either 1,2- or 1,3-diol, as didentate ligand, coordinates to a hydrolyzed iron(III) ion at acidic pH. In all of the present systems of iron(III) and polyols, iron(III) hydroxide-like precipitates resulted at around neutral pH. The polyols were removed in some quantities from solutions by adsorption on the precipitates; the removability depended on their molecular structures. In these polyols, only glycerol, which has three neighboring OH groups, formed soluble complexes at pH > 9 if R > 20. Accordingly, three neighboring OH groups seemed to be essential in the formation of soluble complexes at alkaline pH. In conclusion, the interaction between iron(III) and polyols are severely dependent upon the molecular structures of the polyols.
  • Masaru Kimura, Mari Tokuda, Keiichi Tsukahara
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 10 号 p. 2731-2735
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    Traces of copper(II) ion in 10−7—10−5 M (M = mol dm−3) catalytically accelerated the oxidation reactions of iodide ion to iodine in relatively strong acid solutions (pH ≤ 2) in the presence of molecular oxygen under conditions containing relatively high concentrations of I. When a copper(II) solution was mixed with an iodide solution, after a rapid formation of iodine, it gradually increased according to the reaction times. For about 5 min after mixing, plots of [I3]formed vs. t showed a good straight line; the formation rate of I2 (or I3) increased proportionally with increasing concentrations of copper(II) ion and oxygen, with increasing concentrations of hydrogen ion and iodide ion, and with increasing temperature and with decreasing the ionic strength in the reaction solution. The formation rate of I2 was extremely inhibited by the presence of either radical scavengers or ethylenediaminetetraacetic acid (EDTA). A chain mechanism is presented to account for the obtained results.
  • Ken-ichi Okamoto, Kenji Arashi, Jinsai Hidaka, Takumi Konno
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 10 号 p. 2736-2743
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    Cobalt(III) complexes with 1-thio-β-D-glucose (H5tg), [Co(H4tg-S)2{(en)2 or (tren)}]+ and [Co(H3tg-O,S){(en)2 or (tren)}]+, were newly prepared; where en and tren denote ethylenediamine and tris(2-aminoethyl)amine, respectively. The oxidation products of [Co(H3tg-O,S){(en)2 or (tren)}]+ were prepared by the addition of H2O2. These complexes were separated into their isomers by column chromatography. The crystal structure of -[Co(H3tg-O,S)(en)2]NO3·H2O was determined by X-ray diffraction: This complex, chemical formula CoC10H16O8N5S, crystallizes in orthorhombic, space group P212121, a = 14.328(1), b = 14.617(1), c = 8.605(1) Å, V = 1802.2(3) Å3, Z = 4, and R = 0.055. The geometry around the cobalt atom is approximately octahedral, coordinated by one 1-thio-β-D-glucose and two en ligands. 1-Thio-β-D-glucose takes the cyclic chair form and coordinates to cobalt(III) ion through the close-neighboring sulfur and oxygen atoms. This isomer takes the Δ configuration. The other complexes were characterized by their absorption, CD, 13C NMR spectra. For all of the isomers, the Δ configuration will be more preferentially formed than the Λ one.
  • Isao Sanemasa, Yue Wu, Yuuki Koide, Toshie Fujii, Hiroko Takahashi, To ...
    1994 年 67 巻 10 号 p. 2744-2750
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    Cyclodextrins (CyD’s) were precipitated in aqueous medium at 25 °C as inclusion complexes with twenty-two volatile nonelectrolytes (guests). The guest/CyD molar ratios of precipitates were measured immediately after preparation and after drying. Drying the precipitates for five hours at 50 °C under reduced pressure using a water-suction pump gave the same guest/CyD molar ratios as those obtained by drying in a desiccator over diphosphorus pentaoxide and stored there for two weeks. An iodine–α-CyD complex is quite stable on drying and, next to it are 1,2,3-trimethylbenzene–α-CyD and 1,2,4-trimethylbenzene–β-CyD complexes; other guest–CyD complexes are more or less unstable. The stability was found to be roughly correlated to the van der Waals volume of guest molecule(s) resident maximally in the CyD cavity.
  • Kanakam Chabita, Parikshit C. Mandal, Sudhindra N. Bhattacharyya
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 10 号 p. 2751-2757
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    The reactions of SO4−• radicals with cytosine and its derivatives have been studied in dilute aqueous solutions. The results show that the nature of the group attached to N-1 of the base greatly influences the reaction sequences. Presence of copper(II) ions greatly affects the reaction pathways, where it is observed that the substrate consumption increases drastically indicating initiation of some chain reactions. Release of unaltered base from cytidine and deoxycytidine also increases under these conditions.
  • Yoko Kanna, Tatsuo Arai, Katsumi Tokumaru
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 10 号 p. 2758-2762
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    The quantum yields of the isomerization and photostationary state isomer ratios of the photoisomerization of (4Z,15Z)-bilirubin IXα (ZZ-BR) were determined in an aqueous buffered solution in the presence of human serum albumin (HSA) at a molar ratio of [ZZ-BR]/[HSA] from 0.5 to 2. The BR isomer compositions in the photostationary state were constant at [BR]/[HSA] = 0.5—0.7. With increasing [ZZ-BR]/[HSA] from 0.8 to 2, the ZZ-BR composition in the photostationary state increased from 58 to 75%, but the ZE-BR composition decreased from 39 to 22%. The quantum yields in the isomerization of ZZ-BR to ZE-BR (ΦZZZE) and a cyclized product, lumirubin (LR), (ΦZZ→LR), remained unvaried up to [ZZ–BR]/[HSA] = 1, but ΦZZZE decreased while ΦZZ→LR increased along with a further increase of [ZZ-BR]/[HSA]. These results are explained by the existence of two binding sites, a first-class site and a second-class site, for bilirubin binding to HSA; ΦZZZE in the second-class site (= 0.035) was as low as 1/3 of that in the first-class site (= 0.11), but ΦZZ→LR in the second-class site (= 4.2 × 10−3) was nearly two-times higher than that in the first-class site (= 2.4 × 10−3).
  • Daiyo Terunuma, Kayo Kumano, Yuuki Motoyama
    1994 年 67 巻 10 号 p. 2763-2767
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    Reduction of the 7-silanorbornene derivatives obtained from Diels–Alder reactions of 1,1,3,4-tetramethylsilacyclopenta-2,4-diene (1a), and 2,3-dimethyl-5-silaspiro[4.4]nona-1,3-diene (1b) with maleic anhydride was carried out by lithium aluminum hydride (LAH) to give diol derivatives. Attempts to substitute the hydroxyl groups with chlorine using various chlorination agents such as thionyl chloride and triphenylphosphine in carbon tetrachloride were unsuccessful. The latter reaction, however, gave a corresponding ether derivative as a result of intramolecular cyclization. Reactions of the 7-silanorbornene derivatives with some nucleophiles such as LAH, (n-Bu)4NF, n-BuLi, and PhLi were also investigated.
  • Kazuhisa Sakakibara, Hidetaka Kawamura, Takashi Nagata, Jingzhu Ren, M ...
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 10 号 p. 2768-2778
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    The MM2 force field has been extended so as to deal with periplanone B and nitroxides by using empirical relationships which enable us to derive the MM2 stretching (ks) and bending force (kb) constants systematically. The stretching force constants (ks) could be correlated well with the bond order (N) and equilibrium bond length (r0) by the equation ks = a(N/r03) + b. Three different sets of parameters (a, b) were assigned to the bonds, which were classified according to the atoms forming the bonds. The bending force constants (kb) could be estimated by the equation , where ks1 and ks2 are the stretching force constants of the bonds which comprise the bond angle. The angle types were classified into six groups in the MM2 force field. After assigning ks and kb, the torsional parameters (V1, V2, V3) were determined so as to reproduce the ab initio conformational energies and structural data of the model compounds for the periplanone B and nitroxides. The MM2 calculations using the parameters thus obtained reproduced the experimental structures and conformational energies of periplanone B and the spin adducts of nitrone spin traps correctly.
  • Yutaka Yasuhara, Masaki Nishino
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 10 号 p. 2779-2784
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    The hydrogenation of benzene over a platinum group metal in the presence of various strong acids was carried out. Cyclohexanol derivatives (C6H11X, X = OH, OAc, Cl, Br) were found to be produced by the catalytic hydrogenation of benzene with acid additives. The following two sequences of adsorption strength were observed between platinum metals (adsorbent) and additive reagents (adsorbate) :

    When a weak adsorbate, such as acetic acid or water, was used as an additive reagent, ruthenium, the strongest adsorbent, exhibited the best selectivity. When hydrogen chloride, a strong adsorbate in the sequence (II), was used an additive reagent, palladium or rhodium, moderately strong adsorbent, exhibited excellent selectivity. By the reaction of 2 ml of benzene, 5 ml of 35% HCl and 0.2 g of 5% Pd/SiO2, under 10 atm-G (P atm-G = 1.013(P + 1) × 105 Pa) hydrogen at 100 °C for 20 h, 8.4% of the yield of chlorocyclohexane was obtained at 64.2% of the selectivity (13.1% of the conversion of benzene).
  • Ikuo Shinoda, Akihiko Takahashi, Takao Saito, Tokiko Uchida
    1994 年 67 巻 10 号 p. 2785-2794
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    3,5-Di-substituted 1,2-thiaphospholes were efficiently prepared by treating 2,9-dithia-1-phosphabicyclo[4.3.0]nona-3,7-diene 1-sulfides with n-Bu3P. The thiaphospholes reacted thermally with norbornadiene, norbornene or diethyl azodicarboxylate to produce the 1 : 2 double Diels–Alder cycloadducts. With a mixture of norbornadiene and methyl acrylate or acrylonitrile, the crossed double Diels–Alder cycloadducts were obtained. In the presence of a Lewis acid, the thiaphospholes underwent, at the initial step, the Diels–Alder reaction with acrylic esters, methyl vinyl ketone or acrylonitrile, followed in tandem by the Michael addition of the 1 : 1 cycloadducts to another molecule of the reactant.
  • Akikazu Kakehi, Suketaka Ito, Hideyuki Muranaka
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 10 号 p. 2795-2802
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    The title compounds were first synthesized in considerably good yields by acid-catalyzed dehydration of the corresponding ethyl 2-arylcarbonyl-3-hydroxy-3-phenyl-2,3-dihydrooxepino[2,3-b]indolizin-4-carboxylate derivatives with methanesulfonic acid in boiling chloroform. Although these full-conjugated oxepino[2,3-b]indolizines with a nonaromatic 16π electron system were stable at room temperature, upon heating them in boiling ethanol, they were smoothly rearranged to ethyl 2-arylcarbonyl-1-oxo-2-phenyl-1,2-dihydropyrido[1,2-a]indole-3-carboxylates in good yields. The structures of these oxepino[2,3-b]indolizines and the rearranged pyrido[1,2-a]indol-1(2H)-ones were distinctly determined by physical and spectral means, including X-ray analyses.
  • Arisa Nakamura, Kanji Kubo, Yukari Ikeda, Akira Mori, Hitoshi Takeshit ...
    1994 年 67 巻 10 号 p. 2803-2807
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    Heating 4-allyloxytropones gave Claisen rearrangement products together with oxidation products such as C–C coupling dimers. The products were sensitive to oxygen. Some of the dimeric products were obtained from the cerium(IV) ammonium nitrate-oxidation of 4-hydroxytropones.
  • Jun Li, Akira Harada, Mikiharu Kamachi
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 10 号 p. 2808-2818
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    Oligoethylene (OE) was found to form inclusion complexes with α-cyclodextrin (α-CD) not only from aqueous solutions of α-CD but also from DMF solutions of α-CD to give stoichiometric compounds in a crystalline state in high yields. The yields depend on the oligomeric degree (n) of OE when DMF was used as solvent. OE of n less than 6 did not form complexes with α-CD in DMF solution. The complexes were characterized by IR, 1H NMR, 13C NMR, and 13C CP/MAS and PST/MAS NMR spectra, X-ray (powder), and elemental analysis. The continuous variation plots for the complex formation and the 1H NMR spectra of the complexes show that the stoichiometry of the crystalline complexes is 3 : 1 (ethylene unit–α-CD). The X-ray powder pattern of α-CD–OE complexes and the solid state 13C CP/MAS, PST/MAS NMR spectra suggest that the OE chain is included in the channel formed by α-CD molecules and that the OE backbone in the complexes is more flexible than that in uncomplexed state (OE crystal) due to being included in the cavities of α-CD. Derivatives of OE(6) with small end groups, such as hydroxyl, carboxyl and amino groups, formed crystalline complexes with α-CD, but OE(6) carrying large end groups, such as 2,4-dinitrophenyl and 2,4,6-trinitrophenyl groups, did not form complexes with α-CD. However, it is found that derivatives of OE(6) with charged end groups, such as ammonio or carboxylato groups, do not form crystalline complexes with α-CD, but can form 1 : 1 (guest molecule–α-CD) complexes which are in equilibrium in aqueous solution. The complexation of diammoniohexaethylene cation (DAHE cation) with α-CD in aqueous solution was discussed by using 1H NMR and 2D NOESY NMR spectra.
  • Tatsuro Kijima, Shinji Yamamoto, Hideo Kise
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 10 号 p. 2819-2824
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    The fluorescence spectra of subtilisin Carlsberg (STC) and subtilisin BPN′ (STB) were measured in aqueous–organic mixed solvents over a wide range of solvent composition. The tryptophan fluorophores were used as probes of the environmental polarity, and the structural changes of the enzymes were detected as changes of the difference in the emission wavelength between the enzymes and N-acetyl-L-tryptophan ethyl ester (Δλem). It was found that Δλem was well correlated with the catalytic activity of the enzymes, as expressed by the hydrolysis rate of N-acetyl-L-tyrosine ethyl ester. For example, the characteristic dependency of the activity of STC on the solvent composition in acetonitrile–water was closely related to the change in Δλem. Similar correlations between Δλem and the catalytic activity were observed for subtilisins in aqueous 1,4-dioxane, THF, DMF, DMA, and DMSO solutions with high correlation coefficients, except for STB in water–DMF and –DMA. The results are discussed in terms of the structural modification of the enzymes in these aqueous–organic media.
  • Michinori Oki, Kiyoka Maeda, Tadashi Akinaga, Yasukazu Kataoka, Shinji ...
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 10 号 p. 2825-2830
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    Addition of positive bromine compounds to the title olefins was carried out with use of N-bromosuccinimide–water and t-butyl hypobromite and the results are compared with the case of bromine addition. In the case of the ap-isomer, the reactions reported here all produce bromo-olefins in addition to an addition product, in contrast to the case of bromine which gives only an addition product. The sp-isomer afforded the same products as was observed for the bromine-addition but with different proportions of the products. The anionic species of more proton affinity and consequently of less affinity toward carbocations caused a decrease in formation of the addition product and an increase in formation of bromo-olefins in the case of the ap-isomer. The ratios of products, bromo-olefins to a cyclized compound, were affected by the anionic species in the case of sp-isomer: Both N-bromosuccinimide–water and t-butyl hypobromite yielded about the same amounts of the two olefins, but the yields of the cyclized compound varied significantly. The results are not explained in a straightforward manner. Probably solvent effects are important. In addition, the reaction of the sp-form with N-bromosuccinimide in tetrahydrofuran-water afforded (7R*,7aS*,12bS*)-7-bromomethyl-8-[(E)-bromomethylene]-7-methyl-7a-[(Z)-3-oxo-1-propenyl]-7,7a,8,12b-tetrahydrobenzo[5,6]pentaleno[1,2-a]naphthalene, a compound which is derived by cleavage of a benzene ring. The structural features of the last compound are also discussed.
  • Michinori Oki, Masaki Matsusue, Tadashi Akinaga, Yoshinobu Matsumoto, ...
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 10 号 p. 2831-2837
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    As an example of a set of rotational isomers of triptycenes that carry a secondary alkyl group at the 9-position, 9-alkyl-1,8-difluorotriptycenes (alkyl = isopropyl or 3-hydroxy-1-methylpropyl) were synthesized and their rotational isomerism was examined by means of NMR spectroscopy. For the isopropyl compound, the ap and sc isomers were observed in a 6.2 : 1 ratio in chloroform-d, but the two diastereomeric rotamers were inseparable. X-Ray analysis of the compound reveals that all molecules take ap conformation about the C9–Calkyl bond in crystal. In contrast three rotamers of 3-hydroxy-1-methylpropyl compound could be isolated by HPLC as stable entities at room temperature. Barriers to rotation in chloroform-d were found to be 26.6, 26.3, 25.0, 24.6, 24.8, and 24.9 kcal mol−1 for sc*(S*) → ap(R*), sc*(S*) → sc*(R*), ap(R*) → sc*(S*), ap(R*) → sc*(R*), sc*(R*) → ap(R*), and sc*(R*) → sc*(S*) processes, respectively, at 39.5 °C.
  • Yoshinao Tamaru, Masanari Kimura, Shuji Tanaka, Sigeru Kure, Zen-ichi ...
    1994 年 67 巻 10 号 p. 2838-2849
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    2-Propynyl tosylcarbamates 1 undergo cyclization smoothly by the catalysis of CuCl/Et3N or AgNCO/Et3N to furnish 4-methylene-2-oxazolidinones 2 in good yields. The similar cyclization of the N-acyl derivatives of 1 (PhCO, MeCO, EtOCO, etc.) is catalyzed effectively by AgNCO/t-BuOK. These reactions accommodate a variety of substituents at C1 and C3 of 2-propyn-1-ol and provide (Z)-2 as single stereoisomers. The scope of the cyclization of 3-butynyl carbamates is rather limited, and in general only N-tosyl derivatives of terminally unsubstituted 3-butyn-1-ols undergo cyclization to give 4-methylenetetrahydro-1,3-oxazin-2-ones in synthetically useful yields by the catalysis of AgNCO/Et3N or AgNCO/t-BuOK.
  • Tomoyuki Kitano, Toshihiro Nakai, Masahiro Nitta, Miki Mori, Sotaro It ...
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 10 号 p. 2850-2855
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    The performance of silica supported Pd–Cu composite catalyst developed previously for direct oxidation of benzene to phenol has been improved by changing the copper ion source from Cu(II) sulfate to Cu(II) phosphate and by additional impregnation of phosphoric acid. The reaction proceeds under the simultaneous feeding of benzene, hydrogen and oxygen at 200 °C with a rate of phenol production ca. 0.4 mmol h−1 (g-cat)−1, which is ten times greater than that we have reported previously with a catalyst prepared from Cu(II) sulfate. With this catalyst, complete oxidation to carbon dioxide is also retarded to increase the selectivity of phenol. The improvement of catalytic activity arises apparently from the diminution of the yield of water and is ascribed to the presence of a thin liquid film over the silica surface.
  • Noriaki Manada, Masato Murakami
    1994 年 67 巻 10 号 p. 2856-2860
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    A novel synthesis of chloroformate was developed by palladium-catalyzed reaction of XCl (X = H or NO), CO, and alkyl nitrite in the gas phase. When PdCl2/γ-Al2O3 or PdCl2/SiO2 was used as a catalyst, chloroformate was produced in good yield and with high selectivity. The reaction temperature had a strong influence on the formation rate of chloroformate, and its selectivity drastically depended on the nitrite/chloride ratio. When the nitrite/chloride ratio was less than 2, the selectivity of chloroformate was almost 100%. Dependence of the formation rate on the concentrations of CO and methyl nitrite was also examined.
  • An Sheng Wang, Yoshihisa Matsui
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 10 号 p. 2861-2863
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    The 1H NMR spectrometry of aliphatic aldehydes in D2O showed that the addition of α-cyclodextrin (α-CD) causes a marked change in the hydration equilibrium of ethanal in favor of the unhydrated aldehyde. The inhibitory effect of α-CD on hydration was smaller in propanal than in ethanal and negligible in butanal, pentanal, and hexanal.
  • Yukiharu Miwa, Matsuhiko Nishizawa, Tomokazu Matsue, Isamu Uchida
    1994 年 67 巻 10 号 p. 2864-2866
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    A conductometric glucose sensor was fabricated by coating a twin-microband electrode with a bilayer of a membrane composed of polyaniline and glucose oxidase/gluconolactonase films. The enzyme-catalyzed hydrolysis of glucose induces a change in the conductivity of the pH-sensitive polyaniline film. The conductivity change was detected by the current flowing between the two-band electrode. The sensor demonstrates clear responses to glucose up to 1 mM.
  • Kunio Tamaki, Yoko Ohara, Nanae Ogawa, Yoichiro Domae, Tetsuya Kurokaw ...
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 10 号 p. 2867-2869
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    The surface tensions are reported for aqueous solutions of four series of homologous N,N′ -polymethylenebis(trialkylammonium) dibromides [(CmH2m+1)3N(CH2)nN(CmH2m+1)3]Br2 (m = 1—4) at 25 °C. The experimental results are discussed with emphasis on the behavior of these salts in water. It is generally recognized that the structure-breaking solutes are surface inactive in aqueous solutions, whereas hydrophobic structure-making solutes are surface active in aqueous solutions. The critical micelle concentration for [(C4H9)3N(CH2)12N(C4H9)3]Br2 is estimated to be 0.07 mol dm−3.
  • Sadakatsu Nishikawa, Naoki Kuramoto, Tomoko Uchiyama
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 10 号 p. 2870-2872
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    After 5-methoxy-1-pentanol was synthesized, the sound velocity, density, and ultrasonic absorption coefficients in the frequency range from 7.5 to 220 MHz were measured in aqueous solutions at 25 °C. The sound velocity and density were reported in terms of the polynomials as a function of the analytical concentration. The absorption could be described approximately by a single Debye-type relaxational equation in the 2.00 and 5.00 mol dm−3 range. The cause of the relaxation was attributed to a perturbation of an equilibrium associated with an interaction between the solute and the solvent; the rate and thermodynamic constants were determined. The results are discussed by comparing them with those previously reported in relation to the water structure.
  • Yukio Hoshino, Noboru Takeno
    1994 年 67 巻 10 号 p. 2873-2875
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    3-Benzylidene-4-chromanones were converted to 3-benzylchromones in HMPA at 200 °C in excellent yields. The reaction was irreversible and efficiently promoted by palladium catalysts in a remarkably shortened reaction time (3 h), compared with the existing procedure (24 h).
  • Satoshi Moriyama, Takahiro Mochizuki, Yasuko Ohshima, Takao Saito
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 10 号 p. 2876-2879
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    Phenyl esters of 2-substituted 5,6-dihydro-2H-naphtho[1,2-b]thiopyran-3-carbodithioic acids (2) reacted with 2-norbornene, dimethyl acetylenedicarboxylate, diethyl azodicarboxylate, N-phenylmaleimide, dimethyl fumarate, 2-chloroacrylonitrile, methyl acrylate, and styrene in refluxing benzene to give the [4+2]cycloadducts, while the thermal cycloaddition reaction of O-methyl esters of 2-substituted 5,6-dihydro-2H-naphtho[1,2-b]thiopyran-3-carbothioic acids (3) was successful only with the triple-bonded dienophiles such as dimethyl acetylenedicarboxylate and ethyl propiolate. In the presence of a Lewis acid (AlCl3 or EtAlCl2), the reactions of both 2 and 3 were found to proceed efficiently even at room temperature.
  • Koji Maeda, Yoshinobu Inouye
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 10 号 p. 2880-2882
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    Enantiometrically pure (R)-(2-cyclopentenyl)methanol (2) was prepared from ethyl 2-oxocyclopentanecarboxylate. Coupling of 2 with 4,4-dimethyl-3-phenylthio-2-cyclohexenone gave an enol ether, which was converted into (8R,11R)-precapnelladiene, = −70.7°, in 6 steps.
  • Jun-ichi Tateiwa, Hiroki Horiuchi, Masakazu Suama, Sakae Uemura
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 10 号 p. 2883-2885
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    The five isomers of phenylbicyclooctanes were produced by Friedel–Crafts transannular alkylation of benzene with (Z,Z)-1,5-cyclooctadiene (1,5-COD) in the presence of a cation-exchanged montmorillonite (Mn+-mont). Mn+-Mont could be used repeatedly to provide the same products in good yields.
  • Yasuhiro Tanoue, Akira Terada, Kazunori Sakata, Mamoru Hashimoto, Shin ...
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 10 号 p. 2886-2887
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    Taking into account the fact that the long-range 13C–1H coupling constant 3JCH is greater than 2JCH, positional assignments of a substituent group of 3-substituted juglones were easily accomplished by off-resonance 13C NMR spectra using a 60-MHz instrument for 1H. This method was applicable to a structural determination of naphthazarin derivatives.
  • Shunya Takahashi, Hiroyuki Terayama, Nobuo Sakairi, Hiroyoshi Kuzuhara
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 10 号 p. 2888-2890
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    An allopyranosyl analog of allyl N,N′-diacetylchitobioside was converted to the corresponding N,N′-diphthaloylated glycosyl acetate in good yield. A thioglycosidation reaction of the glycosyl acetate gave phenyl 3,6-di-O-acetyl-4-O-(3,4,6-tri-O-acetyl-2-deoxy-2-phthalimido-β-D-allopyranosyl)-2-deoxy-2-phthalimido-1-thio-β-D-allopyranoside, the key intermediate employed in the total synthesis of an insect chitinase inhibitor, allosamidin.
  • Tetsuro Shimo, Kazuhiro Ohshima, Kenichi Somekawa, Masaru Kawaminami
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 10 号 p. 2891-2893
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    The hydrolysis of [2+2]cycloadducts 4 or their hydrates 5, which were obtained from the regioselective photoreactions of 4-hydroxy-2,5-dimethyl-3(2H)-furanone (1) with cyanoethylenes, afforded the tittle γ-lactams 7 via an interesting ring transformation.
  • Kiyomi Okabe, Kazuhiro Sayama, Hitoshi Kusama, Hironori Arakawa
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 10 号 p. 2894-2897
    発行日: 1994年
    公開日: 2006/08/01
    ジャーナル 認証あり
    The surface Sr/La ratio of SrO–La2O3 catalysts was almost unchanged within the bulk ratio of Sr/La = 0.02—0.2 when calcined at 1173 K. The reaction results showed that the selectivity to C2+ hydrocarbons depends on the catalyst preparation, which affects the surface morphology and the basicity of the catalysts.
Errata
feedback
Top