Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
75 巻 , 4 号
選択された号の論文の37件中1~37を表示しています
  • Yasuhisa Mizutani, Teizo Kitagawa
    原稿種別: scientific monograph
    2002 年 75 巻 4 号 p. 623-639
    発行日: 2002年
    公開日: 2002/04/15
    ジャーナル 認証あり
    Recent experimental work on vibrational energy relaxation of metalloporphyrins in a condensed phase carried out in this laboratory is summarized. The formation of a vibrationally excited photoproduct of metalloporphyrins upon (π, π*) excitation and its subsequent vibrational energy relaxation were monitored by picosecond time-resolved resonance Raman spectroscopy. Results related to intramolecular relaxation of octaethylporphyrinato nickel (NiOEP) are described. Stokes Raman bands due to a photoproduct of NiOEP instantaneously appeared upon the photoexcitation. Their intensities decayed with a time constant of ∼300 ps, which indicates an electronic relaxation from the (d, d) excited state (B1g) to the ground state (A1g), being consistent with the results of transient absorption measurements. Anti-Stokes ν4 and ν7 bands for vibrationally excited (d, d) state of NiOEP decayed with time constants of ∼10 and ∼300 ps. The former is ascribed to vibrational relaxation, while the latter corresponds to the electronic relaxation from the (d, d) excited state to the electronic ground state. While the rise of anti-Stokes ν4 intensity was instrument-limited, the rise of anti-Stokes ν7 intensity was delayed by 2.0 ± 0.4 ps, which indicates that intramolecular vibrational energy redistribution has not been completed in the subpicosecond time regime. To study the mechanism of intermolecular energy transfer, solvent dependence of the time constants of anti-Stokes kinetics was investigated using various solvents. No significant solvent dependence of the rise and decay constants was observed for NiOEP. For an iron porphyrin, we observed two phases in intermolecular energy transfer. The fast phase was insensitive to solvent and the slow phase depended on solvents. A model of classical thermal diffusion qualitatively reproduced this behavior. For myoglobin, temporal changes of the anti-Stokes Raman intensity of the ν4 and ν7 bands demonstrated immediate generation of a vibrationally excited heme upon photodissociation and subsequent decays of the excited populations, whose time constants were 1.1 ± 0.6 and 1.9 ± 0.6 ps, respectively. This direct monitoring of the cooling dynamics of the heme cofactor within the protein matrix allows the characterization of the vibrational energy flow through the protein moiety and to the water bath. For solute–solvent energy transfer process, low-frequency modes of proteins seem to be less important.
  • Mitsuhiro Shibayama, Tomohisa Norisuye
    原稿種別: scientific monograph
    2002 年 75 巻 4 号 p. 641-659
    発行日: 2002年
    公開日: 2002/04/15
    ジャーナル 認証あり
    A novel methodology for non-destructive and real-time determination of the gelation threshold for both chemical and physical systems has been proposed. This method i.e., a time-resolved dynamic light scattering (TRDLS) measurement, allows one not only to determine the gelation threshold but also to investigate critical dynamics near gelation threshold, mechanism of gelation, and architecture of gelling cluster. The gelation threshold was found to be characterized by (1) the appearance of a speckle pattern in the scattering intensity, (2) a power-law in the intensity–time correlation function (ICF), (3) a specific broadening of the distribution function, and (4) a noticeable suppression of the initial amplitude of ICF. All of these features originate from some unique aspects of gels: nonergodicity, frozen inhomogeneities, and divergence of connectivity correlation. As an application of these concepts, we propose four methods for determination of gelation threshold and examine their validity and usefulness for various types of gels; these include chemical gels of N-isopropylacrylamide, a gelling system of silica gel in a reaction batch, thermoreversible physical gels of poly(vinyl alcohol)–Congo Red complex, and biological gels of gelatin and globular protein.
  • Takahiro Sasamori, Yoshimitsu Arai, Nobuhiro Takeda, Renji Okazaki, Yu ...
    原稿種別: technical report
    2002 年 75 巻 4 号 p. 661-675
    発行日: 2002年
    公開日: 2002/04/15
    ジャーナル 認証あり
    The first stable distibene (RSb=SbR) and dibismuthene (RBi=BiR) were successfully synthesized by taking advantage of steric protection using an efficient steric protection group, 2,4,6-tris[bis(trimethylsilyl)methyl]phenyl (Tbt). Since it is quite difficult to investigate the reactivities of the distibene (TbtSb=SbTbt) and dibismuthene (TbtBi=BiTbt) in solution due to their extremely low solubility values, similarly overcrowded distibene and dibismuthene, BbtE=EBbt (E = Sb, Bi), with sufficiently high solubility were also synthesized using another bulky substituent, 2,6-bis[bis(trimethylsilyl)methyl]-4-[tris(trimethylsilyl)methyl]phenyl group (Bbt). The crystallographic analysis and spectroscopic studies of these stable dipnictenes led to the systematic comparison of structural parameters and physical properties for all homonuclear doubly bonded systems between heavier group 15 elements. In addition to these experimentally obtained results, theoretical calculations for these doubly bonded systems also revealed the intrinsic character of dipnictenes.
  • Eun Sun Min, Sang Il Nam, Mu Sang Lee
    原稿種別: Others
    専門分野: TP
    2002 年 75 巻 4 号 p. 677-680
    発行日: 2002年
    公開日: 2002/04/15
    ジャーナル 認証あり
    A chemical etching method with HNO3-prepared silver foils was used for a Raman study. These foils were found to exhibit a strong SERS effect. An SEM image clearly shows that spherical particles exist in an oxidized state, with diameters in the range of 200 nm for oxidized silver. SERS spectrum of Indigo was taken to illustrate the usefulness of this sample preparation technique. HNO3-roughened silver foils seemed to be more easily prepared substrate systems for SERS studies. There is a high potential that this technique can be used in studies concerning the adsorption, molecular orientation, surface reaction, and surface catalysis at room or elevated temperatures.
  • Anwar Ali, Anil Kumar Nain
    原稿種別: Others
    専門分野: TP
    2002 年 75 巻 4 号 p. 681-687
    発行日: 2002年
    公開日: 2002/04/15
    ジャーナル 認証あり
    The density (ρ) and ultrasonic speed (u) in binary mixtures of benzyl alcohol (BA) with formamide (FA), N-methylacetamide (NMA), N,N-dimethylformamide (DMF), and N,N-dimethylacetamide (DMA), including those of pure liquids, were measured at 35 °C over the entire composition range. The isentropic compressibility (ks), deviations in isentropic compressibility (Δks) and ultrasonic speed (Δu) from linear dependence on the composition, excess volume (VE), apparent molar isentropic compressibility (Kφ,s) and apparent molar volume (Vφ) of amides in benzyl alcohol were calculated. The variation of these parameters with composition of the mixtures suggests that the strength of interaction (BA–FA) < (BA–BA) or (FA–FA), whereas the interaction (BA-substituted amide (NMA, DMF, and DMA)) > (BA–BA) or (amide–amide). Moreover, the values of Δks are found to depend on the positions of the methyl groups, while those of VE seem to depend on the number of such groups in the amide molecule.
  • Shigendo Enomoto, Miki Hasegawa, Tetsutaro Yoshinaga, Hiroshi Hiratsuk ...
    原稿種別: Others
    専門分野: TP
    2002 年 75 巻 4 号 p. 689-693
    発行日: 2002年
    公開日: 2002/04/15
    ジャーナル 認証あり
    The electronic absorption spectra of fluoranthene (abbreviated as FA) were measured in various solvents together with the polarization spectrum with the aid of the stretched polymer film technique. The electronic structure of FA is discussed in comparison with MO calculated results. The polarization directions of the electronic transitions of FA were determined. For instance, the 404 (very weak) and 360.3 nm bands are polarized along the shorter and the longer (C2-) molecular axes, respectively. A weak van der Waals type FA–benzene complex formation was recognized in cyclohexane. The equilibrium constants for this complex formation were determined at various temperatures, e.g. K = 0.147 ± 0.03 dm3·mol-1 at 298 K. The enthalpy, entropy, and free-energy changes are estimated to be ΔH° = -5.9 ± 1.2 kJ·mol-1 (-1.4 ± 0.3 kcal·mol-1), ΔS°298 = -36 ± 1.0 J·K-1 mol-1 (-8.7 ± 0.24 cal·K-1 mol-1), and ΔG°298 = 4.7 ± 0.4 kJ·mol-1 (1.1 ± 0.1 kcal·mol-1). This ΔH° value is considerably small compared with the familiar hydrogen bonding energy, ca. -12 kJ·mol-1(-3 kcal·mol-1).
  • Yuki Uchida, Chie Okabe, Atsushi Kishi, Hideyoshi Takeshita, Yoshio Su ...
    原稿種別: Others
    専門分野: TP
    2002 年 75 巻 4 号 p. 695-703
    発行日: 2002年
    公開日: 2002/04/15
    ジャーナル 認証あり
    Temperature and pressure effects on the Raman spectra due to the intramolecular vibrations of charge transfer crystals of 2-(4-methoxyphenyl)-1,4-benzoquinone and quinhydrone were studied. In quinhydrone crystals involving the intermolecular charge transfer and the intermolecular hydrogen bonding, the temperature- and pressure-induced frequency shifts of the intramolecular vibrations showed blue and red shifts with decreasing temperature and increasing pressure depending on the vibrational modes. In the yellow crystal of 2-(4-methoxyphenyl)-1,4-benzoquinone involving the intramolecular charge transfer, and in the red crystal involving both the intra- and intermolecular charge transfers, the frequencies of the intramolecular vibrations showed only blue shift with increasing pressure. This blue shift was larger in the yellow crystal than in the red crystal. It was also observed that phase transitions take place under 1.8 and 2.7 GPa in quinhydrone crystal and that the phase transitions take place under 1.5 and 2.5 GPa in the yellow and red crystals of 2-(4-methoxyphenyl)-1,4-benzoquinone, respectively.
  • Fumihiko Kitagawa, Noboru Kitamura
    原稿種別: Others
    専門分野: TP
    2002 年 75 巻 4 号 p. 705-709
    発行日: 2002年
    公開日: 2002/04/15
    ジャーナル 認証あり
    A laser trapping picosecond fluorescence microspectroscopy system was combined with a high pressure cell to study droplet size and pressure effects on chemical phenomena in single micrometer-sized oil droplets. When a rectangular capillary tube was used as a pressure cell, single oil droplets were easily and stably trapped by a 1064-nm laser beam even under high pressure. The developed system enabled us to pressurize a sample emulsion as high as 75 MPa; such pressure was enough to induce pressure and droplet-size effects on the fluorescence dynamics of an Acridine Orange derivative (C12-AO+) in single oil droplets. In particular, droplet-size effects on the fluorescence dynamics were pronounced with an increase in static pressure. Possible origins of the pressure and droplet-size effects were discussed.
  • Yutaka Matsumi, Mitsuhiko Kono, Toshio Ichikawa, Kenshi Takahashi, Yut ...
    原稿種別: Others
    専門分野: TP
    2002 年 75 巻 4 号 p. 711-717
    発行日: 2002年
    公開日: 2002/04/15
    ジャーナル 認証あり
    An instrument for the measurement of troposphric OH radical concentrations using a laser-induced fluorescence technique has been developed. Ambient air is expanded through a pinhole into a low-pressure fluorescence cell and irradiated by the second harmonic of a dye laser at a high repetition rate of 1 kHz. The OH radicals are electronically excited using A2Σ+(ν′ = 0) ← X2Π (ν′′ = 0) transitions around 308 nm. The fluorescence from OH radicals is collected by a lens system and detected by a photomultiplier. The photoelectron pulses from the photomultiplier are processed by a photon-counting system. The dynode gate of the photomultiplier and counting gate systems are made to minimize the detection of the chamber and Rayleigh scattering signal. The sensitivity of the developed instrument is calibrated with two methods: one is a long-path absorption technique and the other is a titration technique with simultaneous photolysis of water vapor and oxygen. It is found that the background signal is mainly produced by after-pulse effects in the photomultiplier for the fluorescence detection with a dynode gate system. The minimum detection limit is determined to be 7.0×105 molecules cm-3 for OH radicals with a signal-to-noise ratio of 2 and a signal integration time of 60 s.
  • Noriaki Funasaki, Seiji Ishikawa, Saburo Neya
    原稿種別: Others
    専門分野: TP
    2002 年 75 巻 4 号 p. 719-723
    発行日: 2002年
    公開日: 2002/04/15
    ジャーナル 認証あり
    Internal reference compounds suitable for proton chemical shift measurements of organic anions in deuterium oxide solutions are proposed and used to determine the binding constant of sodium hexane-1-sulfonate (SHS) and α-cyclodextrin (α-CD). The chemical shift of the methyl proton of sodium methyl sulfate (MeS), referred to external sodium 4,4-dimethyl-4-silapentane-1-sulfonate (DSS), changes linearly with the α-CD concentration, because of the volume magnetic susceptibility effect. The chemical shifts of the SHS methyl proton, referred to external DSS and corrected for this magnetic susceptibility effect, as well as referred to internal MeS and methanol (MeOH), provide reliable binding constants of SHS and α-CD. Therefore, MeS and MeOH are appropriate internal standards for organic anions. The present results serve not only for choosing appropriate internal references and the internal or external standard method for chemical shift measurements but also for correcting the chemical shift referred to an external standard.
  • Rui-Hu Wang, Mao-Chun Hong, Wei-Ping Su, Yu-Cang Liang, Rong Cao, Ying ...
    原稿種別: Others
    専門分野: AI
    2002 年 75 巻 4 号 p. 725-730
    発行日: 2002年
    公開日: 2002/04/15
    ジャーナル 認証あり
    Three copper coordination polymers containing organosulfur ligands ({[CuI2(bpsb)3(ClO4)](ClO4)}n (1), {[CuI2(bpsb)3Cl](ClO4)}n (2), and {[CuII(bpb)2Br](ClO4)·3dmf·MeCN}n (3) (bpsb = 1,2-bis[(2-pyrimidinyl)sulfanylmethyl]benzene, bpb = 1,2-bis[(4-pyridyl)sulfanylmethyl]benzene, dmf = N, N-dimethylformamide)) were synthesized and characterized by X-ray structural analysis. Complexes 1 and 2 have similar structures. In both, each bpsb molecule exhibits an exo-bidentate coordination fashion and bridges 3-coordinated copper(I) and 4-coordinated copper(I) through pyrimidinyl rings. Thus, six copper(I) centers, three 3-coordinated and three 4-coordinated located at two different planes alternatively, are linked by six bpsb molecules forming a crown-like nanocavity; such nanocavities make up a 2-D lamellar structure. In complex 3, each copper(II) center adopts a distorted square pyramidal coordination mode; each bpb molecule acts as an exo-bidentate ligand through coordinating to copper(II) atoms in two different directions to form a square unit with solvent molecule guests. Such square units share copper atoms and generate a single-stranded infinite 1-D chain structure.
  • Akio Yuchi, Yuka Sotomura, Kaoru Ueda
    原稿種別: Others
    専門分野: AI
    2002 年 75 巻 4 号 p. 731-734
    発行日: 2002年
    公開日: 2002/04/15
    ジャーナル 認証あり
    Hydration of polymer complexes of divalent and trivalent metal ions with an iminodiacetate (IDA)-type chelating resin (-LNa2) was studied. The hydration numbers of [(-LH)2MII] for Ca2+ and [(-LH)3MIII] for Y3+ and La3+, which are practically the same as those of the respective aqua ions, indicate simple electrostatic interactions between the carboxylates of monoprotonated species of iminodiacetate, (-LH)-, and hydrated metal ions. In contrast, an appreciably smaller hydration number of [(-LH)3MIII] for Sc3+ than that of the aqua ion suggests involvement of the carboxylates in the coordination sphere. The difference in their interaction modes is discussed.
  • Junhu Wang, Masashi Takahashi, Masuo Takeda
    原稿種別: Others
    専門分野: AI
    2002 年 75 巻 4 号 p. 735-740
    発行日: 2002年
    公開日: 2002/04/15
    ジャーナル 認証あり
    The crystal structures and 166Er Mössbauer spectra for some β -diketonatoerbium(III) complexes have been investigated. The geometries around the Er(III) ions in [Er(dpm)3(H2O)] (1; Hdpm = 2,2,6,6-tetramethyl-3,5-heptanedione), [Er(pta)3(H2O)] (2; Hpta = 1,1,1-trifluoro-5,5-dimethyl-2,4-hexanedione) and [Er2(pta)6] (3) are distorted monocapped trigonal prisms. 3 is a dimeric structure in which one of the chelating oxygen atoms of the pta ligand bridges between the Er(pta)3 fragments. The 166Er Mössbauer spectra for those β -diketonatoerbium(III) complexes show paramagnetic relaxation patterns at 12 K. The estimated relaxation time (τ) is spread out from 0.1 to 1 ns. For the seven-coordinated complexes, τ decrease among with a decrease in the Er(III)–Er(III) distance. τ for the six-coordinated complex of [Er(dpm)3] is as short as 0.4 ns in spite of having a rather long distance of Er(III)–Er(III) ions, suggesting that the τ also depends on the coordination number.
  • Yasuki Yoshimura
    原稿種別: Others
    専門分野: AI
    2002 年 75 巻 4 号 p. 741-747
    発行日: 2002年
    公開日: 2002/04/15
    ジャーナル 認証あり
    The solubilities of soluble mer-(-)-isomers of various tris(amino acidato)cobalt(III) ([Co(aa)3]) in water were determined over the temperature range 5 to 50 °C. From these data the standard free energy (ΔdisG°), enthalpy (ΔdisH°), and entropy of dissolution (ΔdisS°) at 25 °C were estimated and compared with the values reported for mer-(+)-, fac-(-)-, and fac-(+)-isomers of [Co(aa)3]. The solubilities of these isomers increase in the order fac-(+)- < fac-(-)- < mer-(+)- < mer-(-)-isomers for [Co(aa)3] synthesized from amino acids with longer side chains than 2-aminobutyric acid. On the other hand, the increasing sequence of the solubilities for tris(L-alaninato)cobalt(III) ([Co(L-ala)3]) and tris(L-serinato)cobalt(III) ([Co(L-ser)3]) is fac-(+)- < mer-(+)- < fac-(-)- < mer-(-)-isomers. The solubility differences between the mer- and fac-isomers and between the (-)- and (+)-isomers are discussed based on the differences of ΔdisH° and TΔdisS° among these isomers. Furthermore, the influence of introducing hydroxyl and methyl groups into the side chains of the amino acids on the dissolution behavior of [Co(aa)3] is discussed.
  • Toshiyuki Nakashima, Terufumi Fujiwara, Takahiro Kumamaru
    原稿種別: Others
    専門分野: AI
    2002 年 75 巻 4 号 p. 749-755
    発行日: 2002年
    公開日: 2002/04/15
    ジャーナル 認証あり
    The interaction between the zinc(II) complex of 5,10,15,20-tetraphenylporphyrin (Zn(tpp)) and cetyltrimethylammonium chloride (CTAC) at the interface of a CTAC reverse micelle in chloroform and 6 : 5 (v/v) chloroform–cyclohexane has been investigated spectrophotometrically. The spectra of Zn(tpp) in the CTAC reversed micellar solutions provide evidence of formation of the associated species Zn(tpp)CTAC; its Soret band is not influenced by solvent polarity. At a fixed molar ratio of water to surfactant (Rw = [H2O]/[CTAC]), the absorbance at the maximum of the Zn(tpp)CTAC band increases with an increase in the CTAC concentration. In the slope of the plot a discontinuity was found, due to formation of reverse micelles at this CTAC concentration, taken as the critical micelle concentration (cmc). The variations of the spectral data were interpreted quantitatively by applying the pseudophase model. Increasing Rw causes a decrease in the Zn(tpp)-solubilizing ability of reverse micelles, implying that the nucleophilicity of Cl- ion to the central zinc of the complex is dropped by the Cl- hydration at the interface. Furthermore, the standard free energy of micellization, calculated from the cmc data, indicates that the micellization is promoted by the Cl- hydration and by decreasing the chloroform fraction in the bulk organic phase.
  • Masaki Takeuchi, Hiroshi Okochi, Manabu Igawa
    原稿種別: Others
    専門分野: AI
    2002 年 75 巻 4 号 p. 757-764
    発行日: 2002年
    公開日: 2002/04/15
    ジャーナル 認証あり
    Dewwater was collected from January 1993 to December 2000 in Yokohama, Japan, and analyzed for weak acid anions with other major chemical components. The volume-weighted average and medium pH of the dewwater were 4.88 and 6.08, respectively, at our sampling site. Weak acids (carbonate, nitrite, sulfite, formate, and acetate ions) were the major species in the dewwater and were several times higher than those in the rain- and fogwater. The concentrations of these species and ammonium ion can be estimated by the resistance model. The estimated values of N(III) correlate relatively well with the measured values, which shows the origin of N(III) in dewwater is nitrous acid in the ambient air. On the other hand, ammonium ion in the dewwater originated from not only gaseous ammonia but also aerosol ammonium ions. Hydrogensulfite ions in the dewwater which originated from sulfur dioxide are an important species as the precursor of the sulfate and they were stabilized by forming hydroxyalkanesulfonate (HASA). Formic acid and acetic acid in the dewwater originated mainly from gas, while the oxalic acid is from aerosol.
  • Hirotoshi Araya
    原稿種別: Introduction
    専門分野: AI
    2002 年 75 巻 4 号 p. 765-766
    発行日: 2002年
    公開日: 2002/04/15
    ジャーナル 認証あり
    The scrubbing waters of the combustion exhaust gases containing low concentrations of cyanide ion, formaldehyde, phosphate ion and fluoride ion were treated by the methods for concentrated liquid wastes. Such methods were applicable to the scrubbing waters which did not contain fluoride ions.
  • Takashiro Akitsu, Seiko Komorita
    原稿種別: Introduction
    専門分野: AI
    2002 年 75 巻 4 号 p. 767-768
    発行日: 2002年
    公開日: 2002/04/15
    ジャーナル 認証あり
    A copper(II) complex [Cu(succim)2(N-Eten)(H2O)2] (succim = succinimidate and N-Eten = N-ethylethylenediamine) was prepared and characterized by X-ray crystallography and polarized crystal electronic spectra. The complex has a distorted octahedral [CuN4O2] chromophore. The π-donor succim ligands on cis-positions raise the potential of axial coordination up to six-coordination to maintain electroneutrality of the complex.
  • Zhi-Min Zong, Wei-Hong Zhang, Qun Jiang, Jin Lu, Xian-Yong Wei
    原稿種別: Others
    専門分野: OB
    2002 年 75 巻 4 号 p. 769-771
    発行日: 2002年
    公開日: 2002/04/15
    ジャーナル 認証あり
    The photochemical reactions of 1,2,3,4-tetrahydronaphthalene (THN), 9,10-dihydrophenanthrene (DHP), 9,10-dihydroanthracene (DHA), and acenaphthene (AN) with N-bromosuccinimide (NBS) were investigated under N2 atmosphere at room temperature. The results show that the relative reactivities of the hydroarenes toward a photochemical reaction with NBS are THN < DHP < AN << DHA, which is consistent with the stabilities of the radicals produced by benzylic hydrogen abstraction from the hydroarenes. Photochemical reactions of THN and DHP mainly afforded dehydrogenated products, while the photobrominations of the dehydrogenated products from AN and DHA with NBS proceeded readily.
  • Shin-ichiro Isobe, Kanji Kubo, Thies Thiemann, Tsuyoshi Sawada, Tadash ...
    原稿種別: Others
    専門分野: OB
    2002 年 75 巻 4 号 p. 773-779
    発行日: 2002年
    公開日: 2002/04/15
    ジャーナル 認証あり
    Arylhydroxymethano[3]orthocyclo[5](1,8)naphthalenophanes 11, which possess a rigid boat-chair conformation, were prepared by the reaction of 9,10-benzo-3,4,5-[1,8]naphthobicyclo[5.4.1]dodecan-3,9-dien-12-one 8c with aryllithium reagents and treated with hydrobromic acid in dioxane. The intermediary cation generated from 11 rearranged either to a benzo[cd]azulene system of type 12 or to a tricyclic system containing a cyclopropane-unit of type 13, depending on the nature of the aryl substituent on the bridging carbon atom.
  • Marisa Belicchi Ferrari, Franco Bisceglie, Enrico Leporati, Giorgio Pe ...
    原稿種別: Others
    専門分野: OB
    2002 年 75 巻 4 号 p. 781-788
    発行日: 2002年
    公開日: 2002/04/15
    ジャーナル 認証あり
    Novel ligands were obtained by condensation of pyridoxal with thiosemicarbazides substituted with alkyl and aryl moieties on the aminic and/or hydrazinic nitrogen. The spectrophotometric characteristics of the various species are reported. The X-ray structure of two different dimethylthiosemicarbazones of pyridoxal — pyridoxal N1,N2-dimethylthiosemicarbazone monohydrate and pyridoxal N1,N1-dimethylthiosemicarbazone monohydrate — was determined. The change of methyl group position determines in the solid state strong differences which affect the ligand behavior of these compounds. In the first ligand, characterized by X-ray diffraction, the pyridoxal ring is in a zwitterion form, with the phenolic oxygen and the sulfur atoms in trans position to the iminic N atom. The second compound, with both methyl groups on the aminic nitrogen, shows the donor atoms SNO on the same side, making it potentially suitable for coordination to the metal. Biological studies have involved both inhibition of cell proliferation and apoptosis tests on human leukemia cell lines U937. Both ligands inhibited cell growth, but neither of them induced apoptosis. On the basis of the pKa values, the second ligand is more easily dissociable and this allows us to predict the formation of neutral complexes with it.
  • Peter S. J. Canning, Howard Maskill, Katharine McCrudden, Brian Sexton
    原稿種別: Others
    専門分野: OB
    2002 年 75 巻 4 号 p. 789-800
    発行日: 2002年
    公開日: 2002/04/15
    ジャーナル 認証あり
    Products of thermal and photochemical reactions of eleven arenediazonium tetrafluoroborates in various solvents have been analyzed. All compounds in most solvents undergo unimolecular heterolysis to give singlet aryl cations which are captured by solvent. This mechanism is dominant for arenediazonium ions without electron-withdrawing substituents in all solvents, and the only reaction observed in water. Additionally, appreciable yields of fluoroarenes are obtained by fluoride abstraction by the aryl cation from fluorinated solvents and from tetrafluoroborate in fluorinated solvents. Yields from photochemical processes are very similar to those from thermal reactions indicating that the main reactions proceed through common or very similar intermediates. Aryl cations formed from ion-paired diazonium ions may react with the counterion, but fragmentation of dissociated diazonium ions leads only to solvent-derived product. Some arenediazonium ions in some solvents undergo an alternative radical reaction leading principally to hydrodediazoniation. It is proposed that this reaction involves initial rate-limiting electron transfer from ethanol to the arenediazonium ion followed rapidly by homolysis of the resultant aryldiazenyl radical. Within the same solvent cage, the aryl radical then either abstracts an α-hydrogen from the ethanol radical cation generated in the first step to give the reduction product and protonated acetaldehyde, or combines with it at the oxygen to give a protonated aryl ethyl ether.
  • Sengodagounder Muthusamy, Srinivasarao Arulananda Babu, Chidambaram Gu ...
    原稿種別: Others
    専門分野: OB
    2002 年 75 巻 4 号 p. 801-811
    発行日: 2002年
    公開日: 2002/04/15
    ジャーナル 認証あり
    A series of α-diazo carbonyl compounds tethered to cyclopentanone/cyclohexanone/1-tetralone units have been synthesized using a diazomethane solution to construct various fused cyclooctane ring systems via rhodium-generated carbonyl ylides. The reaction of rhodium(II) acetate dimer with various α-diazo carbonyl compounds generated transient cyclic seven-membered ring carbonyl ylides, which underwent facile 1,3-dipolar cycloadditions with dipolarophiles, like N-phenylmaleimide, p-benzoquinone, and DMAD to furnish a variety of fused epoxy-bridged cyclooctane ring systems in a tandem manner. Interestingly, an oxepine ring system was generated via an intramolecular proton transfer of a seven-membered ring carbonyl ylide. A tri-oxa polycyclic compound was obtained in the case of p-benzoquinone as dipolarophile. A single-crystal X-ray analysis of a fused cyclootanoid derivative is reported to decisively establish the structure and stereochemistry of the fused epoxy-bridged cyclooctane ring systems; a further analysis revealed the existence of a unique intermolecular C–H···π interaction motif in the solid-state architecture.
  • Kei Shimoda, Shunsuke Izumi, Toshifumi Hirata
    原稿種別: Others
    専門分野: OB
    2002 年 75 巻 4 号 p. 813-816
    発行日: 2002年
    公開日: 2002/04/15
    ジャーナル 認証あり
    A novel 74 kDa enone reductase which catalyzes the reduction of the exocyclic C–C double bond of enones was isolated from cultured cells of Nicotiana tabacum. The reductase was found to catalyze the enantiofacially selective reduction of the C–C double bond of 2-alkylidenecyclohexanone to give optically active (S)-2-alkylcyclohexanone.
  • Takeshi Kimura, Masayuki Hanzawa, Kazuhiko Tsujimura, Tatsuya Takahash ...
    原稿種別: Others
    専門分野: OB
    2002 年 75 巻 4 号 p. 817-824
    発行日: 2002年
    公開日: 2002/04/15
    ジャーナル 認証あり
    6,10-Diethyl[1,2,3]trithiolo[4,5-h]benzopentathiepin (1) was oxidized by mCPBA in dichloromethane to produce the corresponding four monoxides. The structures of the monoxides 2, 3, 4, and 5 were determined by X-ray crystallography to be 6,10-diethyl[1,2,3]trithiolo[4,5-h]benzopentathiepin 8-oxides (1,2,3-trithiole 2-oxides) for 2 and 3, and 6,10-diethyl[1,2,3]trithiolo[4,5-h]benzopentathiepin 7-oxides (1,2,3-trithiole 1-oxides) for 4 and 5, respectively. Compounds 2 and 3 are isomers with respect to the conformation of the 1,2,3,4,5-pentathiepin ring, and 4 and 5 are also the conformational isomers. These compound pair members, 2 and 3, and 4 and 5, were found to isomerize each other by inversion of the pentathiepin ring. The activation parameters of the isomerization, ΔG298, ΔH, and ΔS, were determined by 1H NMR spectroscopy. Because of the slow inversion of the pentathiepin ring, isolation of unsymmetrically substituted benzopentathiepin as a chiral molecule is possible. Asymmetric oxidation of 1 was performed by a Sharpless reagent [1/Ti(OiPr)4/R,R-DET/t-BuOOH = 1 : 2 : 4 : 4] to produce optically active monoxides 4a and 5a. The configuration of 4a and 5a was confirmed as R configuration on the sulfinyl sulfur atom, respectively. The specific rotation and the circular dichroism spectra of 4a and 5a were measured in chloroform; such data are apparently affected by the conformation of the pentathiepin ring.
  • Miki Murata, Koji Kawakita, Taichi Asana, Shinji Watanabe, Yuzuru Masu ...
    原稿種別: Others
    専門分野: OB
    2002 年 75 巻 4 号 p. 825-829
    発行日: 2002年
    公開日: 2002/04/15
    ジャーナル 認証あり
    The treatment of pinacolborane (4,4,5,5-tetramethyl-1,3,2-dioxaborolane) with vinylarenes in the presence of a catalytic amount of phosphine-free di-μ-chlorobis(1,5-cyclooctadiene)dirhodium(I) [RhCl(cod)]2, through dehydrogenative borylation, provides the corresponding regio- and stereodefined (E)-2-arylethenylboronates in high yields. Also, a ruthenium complex prepared in situ from (1,5-cyclooctadiene)(1,3,5-cyclooctatriene)ruthenium(0) [Ru(cod)(cot)] and P(4-CF3C6H4)3 showed considerable catalytic activity for dehydrogenative borylation.
  • Hirohiko Houjou, Seiji Tsuzuki, Yoshinobu Nagawa, Kazuhisa Hiratani
    原稿種別: Others
    専門分野: OB
    2002 年 75 巻 4 号 p. 831-839
    発行日: 2002年
    公開日: 2002/04/15
    ジャーナル 認証あり
    A new variety of salicylideneaniline derivatives were prepared from a substituted aniline and a bis(hydroxybenzaldehyde) which has been synthesized through a tandem Claisen rearrangement reaction. X-ray crystal structures were obtained for many of the products. With respect to the conformation of their isobutenylene chain, the crystal structures can be classified into three groups: i.e., skew–skew (I), syn–skew (II), and syn–syn (III) conformers. The 1H NMR spectra were significantly different among these compounds, especially for the isobutenylene moiety. The set of the chemical shifts, (δ (Ha), δ (Hb)), of exo-methylene (Ha) and benzylic methylene (Hb) is a good index for classifying the NMR spectra, and these values also reflect the conformation of the isobutenylene chain found in the crystal state. Namely, each conformer of I, II, and III corresponds to the (δ (Ha), δ (Hb)) values (ppm) around (5.10, 3.43), (4.86, 3.43), and (4.74, 3.56), respectively. This result is verified by the complexation study of a 15-crown-5 derivative with alkali metal ions. The chemical shift change caused by the complexation is successfully explained by the conformation changes among I, II, and III.
  • Shin-ichi Usugi, Takayuki Tsuritani, Hideki Yorimitsu, Hiroshi Shinoku ...
    原稿種別: Others
    専門分野: OB
    2002 年 75 巻 4 号 p. 841-845
    発行日: 2002年
    公開日: 2002/04/15
    ジャーナル 認証あり
    Treatment of benzyl bromoacetate with 3-butenylgallium dichloride in ether in the presence of a catalytic amount of Et3B as a radical initiator provided benzyl 3-cyclopropylpropanoate in 64% yield via a radical addition–substitution sequence. The use of 3-butenylindium dichloride in place of the gallium reagent also afforded the same product in good yield.
  • Noriki Kutsumura, Noriko U. Sata, Shigeru Nishiyama
    原稿種別: Others
    専門分野: OB
    2002 年 75 巻 4 号 p. 847-850
    発行日: 2002年
    公開日: 2002/04/15
    ジャーナル 認証あり
    A total synthesis of cis,cis-ceratospongamide 1a, a cycloheptapeptide isolated from the Indonesian red alga Ceratodictyon spongiosum and the symbiotic sponge Sigmadocia symbiotica, was accomplished. The heptapeptide chain 8 was produced by a stepwise connection of the following segments: (L-Phe-L-Pro)-thiazole residue, L-Phe-L-Pro-OMe, and L-Ile-L-aThr-OMe. Macrolactamization of 8, followed by cyclization to an oxazoline ring, provided cis,cis-ceratospongamide 1a along with its diastereomer 1c, which was different from the reported trans,trans-ceratospongamide 1b. The structural determination of 1c and its conversion to 1a were successfully achieved.
  • Firouz Matloubi Moghaddam, Mohammad G. Dekamin, Mohammad S. Khajavi, S ...
    原稿種別: Introduction
    専門分野: OB
    2002 年 75 巻 4 号 p. 851-852
    発行日: 2002年
    公開日: 2002/04/15
    ジャーナル 認証あり
    Aryl and alkyl isocyanates have been efficiently converted into symmetrical trisubstituted aryl and alkyl isocyanurates, catalyzed by sodium p-toluenesulfinate on its own or in the presence of tetrabutylammonium iodide (TBAI), in a solvent-free condition. The latter has been shown to have a higher catalytic activity.
  • Hideki Yorimitsu, Koichiro Oshima
    原稿種別: Introduction
    専門分野: OB
    2002 年 75 巻 4 号 p. 853-854
    発行日: 2002年
    公開日: 2002/04/15
    ジャーナル 認証あり
    Some triethylborane-induced radical reactions were found to proceed in ionic liquids. The reactions include atom transfer radical cyclization, hydrostannylation of alkyne, and atom transfer radical addition. Benzyl bromoacetate participated in the bromine atom transfer addition reaction to 1-octene in 1-ethyl-3-methylimidazolium tetrafluoroborate to afford the corresponding adduct in excellent yield. The facile bromine atom transfer addition in the ionic liquid indicates that the ionic liquid may have a highly polar nature. The ionic liquid used was recyclable in one case, but was not in the other case.
  • Masanori Terasaki, Shinya Nomoto, Hajime Mita, Akira Shimoyama
    原稿種別: Introduction
    専門分野: OB
    2002 年 75 巻 4 号 p. 855-856
    発行日: 2002年
    公開日: 2002/04/15
    ジャーナル 認証あり
    When a hydrogen-oxygen flame was blown against an aqueous solution of urea and maleic acid, N-carbamoylaspartic acid was generated. This compound seemed to be formed by the addition of an amidinoxyl radical to a C–C double bond of the acid, followed by a thermal rearrangement of an amidinoxy to a ureido group.
  • Yo Miyagi, Noriko Banjyo, Emiko Yamamura
    原稿種別: Introduction
    専門分野: OB
    2002 年 75 巻 4 号 p. 857-858
    発行日: 2002年
    公開日: 2002/04/15
    ジャーナル 認証あり
    Good yields of 3,3′,5,5′-tetra-t-butyl-4,4′-diphenoquinone were obtained by the reaction of 2,6-di-t-butylphenol with N,N′-bis(ethoxycarbonyl)-1,4-benzoquinone diimine, which had been shown to undergo addition with aniline derivatives and phenols. The reaction was followed with 1H NMR spectroscopy to deduce the reaction intermediates.
  • Lingaraj Sahoo, Jitendra Sarangi, Pramila K. Misra
    原稿種別: Others
    専門分野: AM
    2002 年 75 巻 4 号 p. 859-865
    発行日: 2002年
    公開日: 2002/04/15
    ジャーナル 認証あり
    The advantage of a change in the vibrational structure of the emission spectra of pyrene as a function of the concentration of a series of polyoxyethylated alkyl ethers and alkylsulfonates has been utilized to explore the co-operative association of ionic and nonionic amphiphiles into micelles, the micropolarity of these micelles and the solubilization site of pyrene in micelles. The results indicate that the micropolarity of the environment experienced by pyrene is alcohol-like. Pyrene preferably resides in the palisade layer of a nonionic micelle, while in the interior of an anionic micelle. A multiple equilibrium model for micelle formation has been suggested and the existence of pre-micellar aggregates has been evidenced from the excimer characteristics of pyrene.
  • Shujiro Hayashi, Yoshiyuki Yokogawa, Takatoshi Kinoshita
    原稿種別: Others
    専門分野: AM
    2002 年 75 巻 4 号 p. 867-870
    発行日: 2002年
    公開日: 2002/04/15
    ジャーナル 認証あり
    LB films consisting of stearic acid (SA) multilayers and silicon substrates without heavy metal were prepared using a computer-controlled LB film deposition apparatus. Using dimethyldioctadecylammonium bromide as the first (or first and second) monolayer(s), up to 70 layers were deposited, and the interference color was expressed. This indicated that the surface charge of the substrate needed to be canceled in order to successfully deposit a multilayer. Moreover, it was demonstrated that LB multilayers of fatty acid could be prepared using a computer-controlled apparatus even without using a heavy metal salt.
  • Fuminori Akiyama
    原稿種別: Others
    専門分野: AM
    2002 年 75 巻 4 号 p. 871-875
    発行日: 2002年
    公開日: 2002/04/15
    ジャーナル 認証あり
    Degradation of char from poly(vinyl chloride) (PVC) or chars from mixtures of PVC and polyethylene glycol (PEG) with potassium carbonate in supercritical water was performed. Degradation of chars from a mixture of PVC and PEG prepared by heating at 250 °C in nitrogen atmosphere with potassium carbonate at 500 °C for 3 h in supercritical water gave a mixture of hydrocarbons in the yield of 11 wt%, in which the content of benzene was only 5%, accompanied by formation of oil in the yield of 16 wt%. The main reaction products in this degradation reaction were water soluble products. The facts that these water-soluble products did not any absorption in 1H NMR and 13C NMR spectra and that these water-soluble products show FT-IR absorptions at 1378 and 1622 cm-1 suggest that these water soluble products are potassium salts of carbon oxides.
  • Ken-ichiro Ota, Katsuya Toda, Shigenori Mitsushima, Nobuyuki Kamiya
    原稿種別: Others
    専門分野: AM
    2002 年 75 巻 4 号 p. 877-881
    発行日: 2002年
    公開日: 2002/04/15
    ジャーナル 認証あり
    The high-temperature corrosion of stainless steels (SUS316L and SUS310S) in the presence of lithium-potassium eutectic carbonate and lithium-sodium eutectic carbonate has been studied by thermogravimetry and the metal consumption method under a carbon dioxide–oxygen atmosphere in the temperature range of 773–1123 K. Although the corrosion of SUS310S obeyed the parabolic rate law for all reaction conditions, the corrosion of SUS316L significantly depended on the reaction conditions. At or above 923 K, the corrosion of SUS316L obeyed the parabolic rate law, even with a carbonate coating. The corrosion rates were accelerated during the initial period of corrosion tests below 923 K, especially around 823 K with a lithium-sodium carbonates coating. The initial accelerated corrosion was a local corrosion, which produced through holes in the metal specimens, and occurred more clearly at higher carbon dioxide partial pressures with the lithium-sodium carbonate coating than with the lithium-potassium carbonate coating.
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