bluuebunny/crossref_metadata_2025_split huggingface dataset:
Light Induced Tritiation of Methyl Benzoate with Diethylamine-N-t and Triethylamine–Tritiated Water Mixture
Authors: Kitamura Akihide , Kaneko Hiroyuki , Morikawa Naotake , Oohashi Kunio , Sakuragi Hirochika , Tokumaru Katsumi , Umeda Mamoru , Yoshida Masayuki 
Published: July 2006

Abstract
Methyl benzoate was tritiated at both nuclear and methyl positions on irradiation with diethylamine-N-t in benzene and with triethylamine–tritiated water in acetonitrile.
5-Fluorouracil Derivatives. II. A Convenient Synthesis of 5-Fluoro-2′-deoxyuridine
Authors: Ozaki Shoichiro , Katakami Tsutomu , Saneyoshi Mineo 
Published: July 2006

Abstract
The reaction of 5-fluorouridine with propionyl bromide in acetonitrile afforded 3′,5′-di-O-propionyl-2′-bromo-5-fluoro-2′-deoxyuridine (2). Compound 2 was then hydrogenated, using Pd–C as the catalyst, to afford 3′,5′-di-O-propionyl-5-fluoro-2′-deoxyuridine (3). Compound 3 was deacylated with methanolic ammonia to give 5-fluoro-2′-deoxyuridine (FUDR). In this way, FUDR, a good antitumor agent, can easily be prepared from 5-fluorouridine by three steps in a 48.9% total yield.
Singlet Excitation Energy Transfer in the Vinyl Polymers with Pendant Carbazolyl Groups
Authors: Itaya Akira , Okamoto Ken-ichi , Kusabayashi Shigekazu 
Published: July 2006

Abstract
The migration of electronic excitation energy in films of poly(N-vinylcarbazole) (PVCz) prepared by the radical and cationic polymerizations(PVCz(r) and PVCz(c) respectively), poly[2-(9-carbazolyl)ethyl vinyl ether] (PCz-EVE), brominated PVCz(BPVCz), and poly(9-acryloylcarbazole) (PACz) has been studied by means of fluorescence-quenching experiments, using dimethyl terephthalate or perylene as a guest molecule. No clear difference in the concentration of the effective intrinsic trap sites was observed between PVCz(r) and PVCz(c) films. The concentration of the sandwich-like excimer site(cE) in a PVCz(r) film was nearly equal to that in a PVCz(c) film, while the concentration of the second excimer site (cS) in a PVCz(r) film was higher than that in a PVCz(c) film by a factor of about 1.6. The value of cE was much larger than that of cS for both films. The second excimer site seems to be a shallow trap. The number of carbazolyl chromophores covered by a singlet exciton during the lifetime was in the following order: PCzEVE&gt;PVCz(r)≈PVCz(c)&gt;PACz≈BPVCz. This order was explained by the concentration of the intrinsic trap sites depending on the distance between neighboring Cz chromophores, the lifetime of the singlet exciton, and the concentration of extrinsic trap sites.
The Efficient Oxidation of Thiols to Disulfides with Thallium(III) Acetate
Authors: Uemura Sakae , Tanaka Sakuya , Okano Masaya 
Published: July 2006

Abstract
The treatment of various kinds of alkane- and arenethiols with thallium(III) acetate in chloroform at 20–30 °C readily affords the corresponding disulfides almost quantitatively, without affecting other functional groups, such as the hydroxyl, amino, and carboxyl in the thiols. Under similar conditions, the reaction of thiobenzoic S-acid with thallium(III) acetate gives thallium(III) thiobenzoate, while that of thioacetic S-acid yields diacetyl disulfide and thallium(I) thioacetate.
Photo-induced Cycloaddition of 1-Nitrocyclooctene and Cyclopentadiene
Authors: Yokoyama Keiichi , Katô Masao , Noyori Ryoji 
Published: July 2006

Abstract
Irradiation of 1-nitrocyclooctene produces first the strained trans isomer, which in turn undergoes thermal Diels-Alder reaction with cyclopentadiene affording the tricyclic adduct.
Photolysis of Benzenesulfonic Acid
Authors: Ogata Yoshiro , Takagi Katsuhiko , Yamada Shin 
Published: July 2006

Abstract
Photolysis of benzenesulfonic acid(1) in an aqueous solution gave sulfurous acid, SO2, and/or sulfuric acid as inorganic products in a total yield of 38.6% based on the consumed 1 along with organic products. The organic products are mainly acidic tarry material containing sulfur(8.7%) together with a small amount of biphenyl (1%). Photolysis of an alkaline solution of 1 afforded a considerable amount of benzene (16%) and biphenyl(&lt;1%). The photolysis is started by the C–S bond fission of 1 to give Ph· and ·SO3H radicals. The quantum yield for decomposition of 1 in acidic conditions is 0.26.
14N Nuclear Quadrupole Resonances of the Molecular Complexes of Urea
Authors: Negita Hisao , Kubo Tsuneo , Maekawa Michio 
Published: July 2006

Abstract
The 14N nuclear quadrupole resonance (NQR) was studied on three kinds of molecular complexes of urea, such as the urea–hydrogen peroxide complex (H2O2 complex), the urea–sodium chloride–water complex (NaCl complex), and the urea–sodium bromide–water complex (NaBr complex). The 14N quadrupole coupling constants and asymmetry parameters are as follows: |e2Qq⁄h|=3493.8 kHz and η=0.3456 for the H2O2 complex; |e2·Qq⁄h|=3597 kHz and η=0.293 for the NaCl complex, and |e2Qq⁄h|=3636.7 kHz and η=0.2778 for the NaBr complex. From the temperature dependence of the resonance frequencies, it is considered that the hydrogen bonds in the H2O2 complex are stronger than those in the NaCl complex. The electron densities at nitrogen atoms in these complexes were derived from the corresponding NQR parameters, and were compared with those in urea.
Proton Transfer between Styrene Molecular Anion and Ethanol in Rigid Organic Matrices
Authors: Noda Shoji , Fujii Yasumi , Yoshida Hiroshi 
Published: July 2006

Abstract
The proton transfer from ethanol to styrene molecular anion was studied by examining the yield of the anion and α-methylbenzyl radical generated in γ-irradiated 2-methyltetrahydrofuran–ethanol mixed matrix at 77 K by means of optical absorption measurements. The radical yield was found to increase in proportion to the ethanol fraction at the expense of the anion yield. The maximum radical yield, 2.2, was identical with the yield of scavengeable electron in ethanol matrix where no anion was observed. Upon photobleaching the anion was transformed into the radical in the matrix. The transformation efficiency was constant, ca. 0.6, for the ethanol fraction 0.3–0.9. It is concluded that the radical arises from the anion through the proton transfer from ethanol to the β-carbon of vinyl group of the styrene anion. The proton transfer occurs readily only when a specific solvent site around the anion is populated by ethanol molecules. Otherwise, the proton transfer does not occur at all because of the restricted translational motion in the rigid matrix.
Ultrasonic and Volumetric Investigation of Aqueous Solutions of Amides
Authors: Kawaizumi Fumio , Ohno Makoto , Miyahara Yutaka 
Published: July 2006

Abstract
The ultrasonic velocity and density of aqueous solutions of N-methylformamide, N,N-dimethylformamide, and N,N-dimethyIacetamide have been measured at 25 and 35 °C over the entire concentration range. The compressibility, excess compressibility, partial molar compressibility, partial molar volume, and pressure dependence of the partial molar volume have been calculated. The concentration dependences of the velocity and density are highly nonlinear, and the velocity maxima are observed in all the amide solutions at ca. 20 mol%. Minima in the partial molar volume exist in solutions of DMF and DMAA, but not in that of MFA. On taking account of the results for viscosity, the velocity maxima are ascribed to the complex formation, and the minima in the partial molar volume, to the competition between the volume increase due to the complex formation and the volume decrease due to the breaking-down of the water structure. The pressure dependence of the partial molar volume shows that amides and water have strong interactions, even in the low-mole-fraction regions for each component.
Threshold Switching in Anthracene Thin Films
Authors: Sadaoka Yoshihiko , Sakai Yoshiro , Kishi Kohhei 
Published: July 2006

Abstract
Threshold switching was observed in anthracene thin films (&lt;3 μm) using a circuit with a high protective resistance. On the other hand, when the protective resistance was small, the switching was erratic and irreproducible. In the latter case, the switching was occasionally accompanied by filamentary damages caused by the excess current focused at the electrically weak spots, and the threshold voltage was poorly dependent on the protective resistance. The threshold-switching characteristics for thin films are interpretable in terms of the transition from the trap-limited SCLC to the trap-filled SCLC. The thermal breakdown model is not adaptable.
Surface Oxidation of the Thin Films of Polycyclic Aromatic Hydrocarbons Studied by X-Ray Photoelectron Spectroscopy
Authors: Yamada Masamichi , Ikemoto Isao , Kuroda Haruo 
Published: July 2006

Abstract
The oxidation of the surfaces of thin films of perylene, pentacene, violanthrene, and mesonaphthodianthrene on exposure to oxygen or to the air was studied by means of X-ray photoelectron spectroscopy. A perylene film was found to be the least reactive toward oxygen among the above four hydrocarbons. In the cases of pentacene and violanthrene films, a single, broad O 1s peak grew up with time over the period of a few months as the exposure to the air was prolonged. On exposure to oxygen, a mesonaphthodianthrene film exhibited the O 1s spectrum which apparently consisted of two peaks located at the binding energies, 531.0 and 532.9 eV respectively, and the peak at 532.9 eV reduced its intensity irreversibly on heating the film in a high vacuum, suggesting that it was the one associated with a loosely bound oxygen.
Vibration Spectra and Rotational Isomerism of Chain Molecules. VI. 2-Chloro-, 2-Bromo-, and 2-Iodoethyl Methyl Ethers
Authors: Matsuura Hiroatsu , Kono Motomichi , Iizuka Hiroshi , Ogawa Yoshiki , Harada Issei , Shimanouchi Takehiko 
Published: July 2006

Abstract
The Raman and infrared spectra of 2-chloro-, 2-bromo, and 2-iodoethyl methyl ethers, CH3OCH2CH2X (X=Cl, Br, and I), were measured for the liquid, glassy, and crystalline states. The gaseous-state spectra of the chloride were also measured. The vibrational frequencies of these molecules were calculated by the use of the force constants transferred directly from unbranched ethers and alkyl halides. The rotational isomerism was studied and the following conclusions were obtained. (1) In the crystalline state, the molecule takes the form having the trans conformation about the CO–CC axis and the gauche conformation about the OC–CX axis. (2) In addition to this form (TG), three other forms (GG, TT, and GT) exist in the gaseous, liquid, and glassy states. (3) In the liquid state, the TG form is the most stable and the GT form is the least stable. (4) The less polar TT and GT forms are more favored and the more polar TG and GG forms are less favored in the gaseous state than in the liquid state.
Chromium(III) Complexes with Amino Acids. III. Chromium(III) Complexes with Acidic, Basic and Carbamoyl Amino Acids
Authors: Oki Hisaya , Takahashi Yasuko 
Published: July 2006

Abstract
Syntheses by both the isothermal matrix in a solid state and by the usual solution method have been tried for chromium (III) complexes with l- and Dl-asparagine, l- and Dl-aspartic acid, l- and Dl-glutamine, l- and Dl-glutamic acid, l- and Dl-lysine, and l-ornithine. [Cr(l-aspNH2)3]·2H2O, [Cr(Dl-aspNH2)3]·3H2O, (NH4)2[Cr(l-asp)2][Cr(d-asp)2]·4H2O, and (+)[Cr(l-lys)2(NH3)(H2O)]Cl·4H2O were obtained by the matrix method in the solid state, while [Cr(l-aspNH2)3]·2H2O, [Cr(Dl-aspNH2)3]·2H2O, and (+)[Cr(l-lys)2(NH3)(H2O)]Cl·4H2O were prepared by the usual solution method. The preparation of chromium(III) complexes with other amino acids was not successful. A new type of complex of chromium(III) containing terdentate Dl-aspartic acid and a new mixed chromium(III) complex containing three different ligands (l-lysine, ammine, and aqua) were prepared.
Determination of Rubidium in Biological Materials Using Atomic Absorption Spectroscopy
Authors: Tanaka Gi-ichiro , Tomikawa Akeo , Kawamura Hisao 
Published: July 2006

Abstract
In order to establish a reliable and rapid method for the determination of rubidium in biological materials using atomic absorption spectroscopy, chemical interference as well as ionization interference due to co-existing elements and some organic substances was studied. In the presence of potassium of sufficient concentration, most of the interference was found to be negligible. The temperature of the sample solutions proved to be a possible source of error. The process of sample preparation was examined, including a determination of the loss of rubidium in dry ashing. The accuracy and precision of the method was tested by analyzing NBS SRM 1577 Bovine Liver. The rubidium contents of typical biological materials—foodstuffs, human tissues and urine— were determined by the present method and a possible relationship between the rubidium and potassium concentrations is indicated.
Synthesis of a Lividomycin B Analogue, 5-O-[3-O-(2-Amino-2-deoxy-α-d-grlucopyranosyl)-β-d-ribofuranosyl]-3′-deoxyparomamine
Authors: Watanabe Isamu , Tsuchiya Tsutomu , Takase Tsuneyuki , Umezawa Sumio , Umezawa Hamao 
Published: July 2006

Abstract
5-O-[3-O-(2-Amino-2-deoxy-α-d-glucopyranosyl)-β-d-ribofuranosyl]-3′-deoxyparomamine was prepared by two different routes. The first route involves glycosylation of a protected N : 6-O-carbonyl-3′-deoxyparomamine with a protected 3-O-(2-amino-2-deoxy-α-d-glucopyranosyl)ribofuranosyl bromide and subsequent removal of the protecting groups. In the second route, 1-N : 6-O-carbnyl-3′-deoxyparomamine was glycosylated with a protected ribosyl bromide having 3-O-benzylthiocarbonyl group to give a pseudotrisaccharide and, after de-3-O-benzylthiocarbonylation, the product was further condensed with a protected 1-bromide of 2-amino-2-deoxy-d-glucose. This synthesized lividomycin B analogue showed only very weak antibacterial activity and the role of the 6'″-amino group of lividomycin in the action was suggested.
Reduction by a Model of NAD(P)H. XV. Kinetics for the Reduction of Methyl Benzoylformate
Authors: Ohno Atsuyosi , Yamamoto Hiroyuki , Okamoto Tadashi , Oka Shinzaburo , Ohnishi Yutaka 
Published: July 2006

Abstract
Kinetics for the reduction of methyl benzoylformate (1) with N-α-methylbenzyl-1-propyl-1,4-dihydronicotinamide (2) in the presence of magnesium perchlorate in acetonitrile at 25 °C has been studied. The reaction follows first-order in 1, first-order in 2, and zero-order in magnesium ion when [2]&lt;&lt;[1], [Mg(ClO4)2]. When [2]= [Mg(ClO4)2]&lt;&lt;[1], the kinetics is best explained by Eqs. 6 and 7. The results indicate that 2 and magnesium ion form a complex, which reacts with 1 at the rate-determining step. It is concluded that magnesium ion activates 2 to promote the release of an electron.
Synthesis of α Substance-IB in Saccharomyces cerevisiae
Authors: Aoyagi Haruhiko , Izumiya Nobuo 
Published: July 2006

Abstract
Two hexapeptides, H–Arg–Gly–Pro–Phe–Pro–Ile–OH (1a) and H–Arg–Pro–Gly–Phe–Pro–Ile–OH (1b), have been proposed for a factor inducing sexual agglutination in the yeast and were synthesized by a conventional method. Compound 1a was completely identical with the natural peptide in thin-layer chromatography, mass spectrometric measurements, and biological assay on agglutination. Compound 1a showed the same biological activity as 1a though distinct differences in the chemical data were observed. Strong bitterness of the 1a and 1b was discovered.
New Method for Synthesis of Various Types of Substituted 2(5H)-Furanones
Authors: Iwai Kiyoshi , Kosugi Hiroshi , Uda Hisashi , Kawai Mikio 
Published: July 2006

Abstract
A combination of the reaction of dianions of (phenylthio) acetic acid and its homologs with epoxides, the conjugate addition reaction of 3-phenylthio-2-(5H)-furanones with carbanion species, and the α-alkylation reaction of α-phenylthio-γ-butyrolactones is shown to provide a general method for the synthesis of a variety of substituted α-phenylthio-γ-butyrolactones. Oxidation of these α-phenylthiolactones to the corresponding sulfoxides, followed by pyrolysis furnishes all the types of substituted (3-, 4-, and 5-mono-; 3,4-, 3,5- 4,5-, and 5,5-di-; 3,4,5-tri-) 2(5H)-furanones in good overall yields.
A Macrocyclic Enzyme Model System. Catalytic Properties of 10-Amino-[20]paracyclophane in the Deacylation of p-Nitrophenyl Carboxylates
Authors: Murakami Yukito , Sunamoto Junzo , Kondo Hiroki , Okamoto Hiroshi 
Published: July 2006

Abstract
The catalytic efficiency of 10-amino[20]paracyclophane in the deacylation of p-nitrophenyl carboxylates was investigated in 10.9 or 20.8% (v/v) aqueous ethanol at μ=0.10 (KCl). The present catalyst exhibited marked catalytic effects not only in the free amine but in the ammonium form. The observed saturation-type kinetics is consistent with a reaction mechanism which involves pre-equilibrium complexation between the aminoparacyclophane and the substrate at a 1 : 1 molar ratio, followed by pseudo-intramolecular catalysis effected by the amino group of the macrocycle. Studies on the inhibition effect by 1-dodecanol and the modification of the catalyst by 2,4-dinitrofluorobenzene confirmed the effective binding ability of the present paracyclophane toward hydrophobic substrates. The free amine form of the catalyst acted as an effective nucleophile to give the acylated aminoparacyclophane as confirmed by the product analysis. On the other hand, the protonated amine form also enhanced the ester degradation, retaining a turnover behavior. On the basis of the kinetic solvent isotope effect and the exceedingly minor kinetic effect of [10-oxo[20]paracyclophan-22(23)-ylmethyl]trimethylammonium chloride in the ester degradation in the neutral pH region, a plausible reaction mechanism has been discussed.
Emission Spectra of Phenol, Anisole, and Phenetole by Controlled Electron Impact
Authors: Tsuji Masaharu , Ogawa Teiichiro , Nishimura Yukio , Ishibashi Nobuhiko 
Published: July 2006

Abstract
Upon the impact of an electron beam (100–450 eV) on PhOH, PhOCH3, PhOC2H5, PhCOCH3, and (Ph)2CO at low pressures, the S1 emission of the parent molecule (not from PhCOCH3 and (Ph)2CO) and the photo-emissions from such fragments as H, CH, CO, CO+, and OH were observed in the 200–520 nm region. It was concluded that the S1 emission of the parent molecule originates through both the S0→S1 and S0→S2 (cascade)→S1 excitation processes and that the direct excitation into the lower vibronic levels of S1 is responsible for the appearance of the vibrational structures. Most excited species including CO+(A) from PhOH were confirmed to be primarily produced; however, CO+(A) from PhOCH3, PhOC2H5, and PhCOCH3, and CO(b) from PhCOCH3 were found to be produced competitively through one-electron and two-electron excitation processes in relation to the intensity measurements. The relative contribution of the two-electron excitation process in producing CO+(A) increased with a larger substituent, and it was larger than that for CO(b) in PhCOCH3.
The Formation of VOSO4 on the Surface of V2O5 in the Oxidation of SO2 as Studied by ESR
Authors: Kera Yoshiya , Kuwata Keiji 
Published: July 2006

Abstract
To obtain information on the arrangements of the VOSO4 phase in the surface layer of the V2O5 single crystal, the angular dependencies of an asymmetric ESR spectrum which has been found in the crystal under the conditions of SO2 oxidation and assigned to the VOSO4 phase were examined in detail. Two types of the angular dependency of the spectrum on the static magnetic field were clearly differentiated from each other. In the main spectrum, the direction of g⁄⁄ was completely consistent with the b-axis of the V2O5 crystal, while, on the other hand, in the minor spectrum, it took rather random orientations. From comparisons of the crystal structures between V2O5 and VOSO4, it was deduced, preliminarily, that the α-VOSO4 phase with a layer structure, was regularly aligned along the layer of the V2O5 lattice and that the β-VOSO4 phase without a layer structure took a relatively random orientation to the lattice.
Asymmetric Shape of Charge-transfer Absorption in Crystalline Ion Radical Salts
Authors: Iida Yôichi 
Published: July 2006

Abstract
Using the one-dimensional Hubbard model, we proposed an asymmetric band shape for the charge-transfer transition between ion radicals in crystalline ion radical salts. The charge-transfer band of the anion radical salts derived from 2,3-dicyano-p-benzoquinone was explained in terms of such a model.
13C-NMR-Spektren von mono- und disubstituierten Cyclohexenen
Authors: Nakagawa Kiyoshi , Sawai Michimasa , Ishii Yasutaka , Ogawa Masaya 
Published: July 2006

Abstract
13C-NMR-Spektren von mono- und disubstituierten Cyclohexenen werden vorgelegt. Für die 13C-chemischen Verschiebungen von disubstituierten Cyclohexenen gelten gute Additivitäten, sofern nicht sterische Wechselwirkungen auftreten und daraus einige Gesetzmässigkeiten abgeleitet werden können, die in der Konfigurations- und Konformationsanalyse von Bedeutung sind.
Para Tolylation of Pyridine by Photolysis of Di-p-Tolyl Sulfone and Related Compounds
Authors: Nakabayashi Takeshige , Horii Toyokazu , Kawamura Shunichi , Hamada Masayuki 
Published: July 2006

Abstract
Di-p-tolyl sulfone, sulfoxide and sulfide, p-toluoyl peroxide, and p-iodotoluene were respectively photolyzed in pyridine with a mercury arc lamp. It was found that all the compounds decompose photochemically to yield the isomeric p-tolylpyridines (α,β , and γ). The isomer distribution ratios (β&gt;α&gt;γ) obtained with the sulfone differ from those (α&gt;β&gt;γ) with the other compounds. The presence of acetone in the reaction system remarkably promoted the photochemical conversion of both the sulfone and sulfoxide.
Synthetic Zeolites as Catalysts for the Ring Conversion of γ-Butyrolactone into 1-Substituted 2-Pyrrolidinones
Authors: Hatada Kou , Ono Yoshio 
Published: July 2006

Abstract
Synthetic zeolites were found to be effective catalysts for the synthesis of 1-substituted 2-pyrrolidinone by the reaction of γ-butyrolactone with amines. 1-Propyl-2-pyrrolidinone was obtained in the equilibrium yield with practically 100% selectivity over copper exchanged Y-zeolite at 280 °C. The effects of reaction temperature, contact time and partial pressures of the reactants were examined. A reaction mechanism is proposed for the ring transformation based on the kinetic studies of the reaction of γ-butyrolactone with propylamine.
Studies of the Measurement of the Intermicellar Concentration of Surfactants by Gel Filtration
Authors: Sasaki Tsunetaka , Yasuoka Misako , Suzuki Hitoshi 
Published: July 2006

Abstract
Equations are derived which are used to calculate the intermicellar concentration (Cs) of a surfactant from measurements of the elution volumes of micelles, the elution front and the intermicellar monodisperse molecules or ions. These quantities are obtained by the gel filtration of a surfactant charged in band form through a gel column previously filled with the same surfactant at a lower concentration. The Cs values found are not constant, but increase and the increase becomes less pronounced with the concentration (C) of the surfactant, both for sodium dodecyl sulfate and α-dodecyl-ω-hydroxyhexa(oxyethylene). This confirms that the concentration C–Cs of the micelles which move during the gel filtration is smaller than the usually-employed concentration C–Cm of micelles in a stationary state, where Cm denotes the critical micelle concentration.