bluuebunny/crossref_metadata_2025_split huggingface dataset:
Photochemistry in Micellar System. II. Photochemical Reduction of β-Arylquinonesulfonates in the Presence of Cationic Surfactants.
Authors: Kano Koji , Takada Yuzo , Matsuo Taku 
Published: July 2006

Abstract
The photochemical reduction of sodium 9,10-phenanthraquinone-3-sulfonate (PQ) and sodium 1,2-naphthoquinone-4-sulfonate (NQ) to the corresponding diols has been studied in water containing cationic surfactants. Photoreduction of PQ was markedly accelerated in the presence of cationic surfactants whereas that of NQ, was highly retarded. Both the acceleration and retardation of the photoreaction of these quinonesulfonates in the presence of cationic surfactants are explained as due to the formation of association complexes betwen the quinones and the surfactants.
Kinetics of the Thermal Decompositions of Diaryl and Dialkyl Disulfides
Authors: Miyashita Tokuji , Matsuda Minoru , Iino Masashi 
Published: July 2006

Abstract
A kinetic study of the thermal decomposition of diphenyl disulfide, its p-methoxy, p-methyl, and p-chloro derivatives, and di-n-butyl and di-t-butyl disulfides in tetralin was made. The rate of decomposition was followed by the decrease of disulfide and the spontaneous first-order rate constants for these disulfides at 196, 207, and 217 °C and the activation parameters were obtained. It was observed that the rates of the decompositions for diaryl disulfides are increased by p-substituents (CH3O&gt;Cl\simeqCH3&gt;H) and that that of di-t-butyl disulfide is comparable to diaryl disulfides, whereas, di-n-butyl disulfide shows no decomposition under these conditions. A reaction scheme of the decomposition including induced decomposition is proposed from the kinetic results and product analysis. Moreover, the properties of a thiyl radical in relation to the above results are discussed from the electronic and ESR spectra of the aryl thiyl radicals generated from the photolysis of corresponding thiols in a glass of 2-methyltetrahydrofuran at −196 °C.
The Asymmetric (Enantioface Differentiating) Hydrogenation of the C=O Double Bond with Modified Raney Nickel. XXIX.
Authors: Harada Tadao 
Published: July 2006

Abstract
In the asymmetric (enantioface differentiating) hydrogenation of methyl acetoacetate with modified Raney nickel catalysts, the effects of the modifying pH on the amounts of the modifying reagents adsorbed and the enantioface differentiating abilities of the catalysts were studied using glycolic acid, mandelic acid, and 2-hydroxy-3-phenylpropionic acid as the modifying reagents. The results indicate that the modifying pH governs the adsorption mode of the modifying reagent. Thus, the change in the adsorption mode of the modifying reagent with the change in the modifying pH results in changes in the amount of the modifying reagent adsorbed and in the enantioface differentiating ability of the catalyst.
Novel Synthesis of Anhydronucleosides via the 2′,3′-O-Sulfinate of Purine Nucleosides as Intermediates
Authors: Sowa Tsuneo , Tsunoda Kozo 
Published: July 2006

Abstract
The synthesis of 8,2′-O-anhydro(9-β-d-arabinofuranosyl)-8-hydroxyadenine (3c) and 8,2′-S-anhydro(9-β-d-arabinofuranosyl)-8-mercaptoadenine (3a) is described. The active intermediates, 2′,3′-O-sulfinyl 8-bromoadenosine (2a), 2′,3′-O-sulfinyl-8-hydroxyadenosine (2c), and 2′,3′-O-sulfinyl-8-bromoguanosine (2d), were prepared from the corresponding nucleosides (1a, 1c or 1d) by successive treatment with thionyl chloride in the presence of pyridine in acetonitrile and with water. The anhydronucleosides, 3a and 3c, were formed in good yields by heating the intermediates (2a or 2c) in n-butanol in the presence of thiourea or in N,N-dimethylformamide in the presence of sodium acetate. All attempts at the cyclization of Compound 2d failed. The reaction product of 8-mercaptoadenosine (1b) with thionyl chloride was identified as the bis(2′,3′-O-sulfinyl adenosin-8-yl) disulfide (2b), which could not be transformed to Compound 3a.
Azafulvenes. 2. Formation of Iminium Salt from Pyrrole- and Indolecarbaldehyde and Its Reaction with Bases
Authors: Kobayashi Takashi , Kajigaeshi Shoji , Kanemasa Shuji 
Published: July 2006

Abstract
Pyrrole- and indolecarbaldehyde reacted with secondary ammonium perchlorate to produce the corresponding iminium perchlorate, which did not afford azafulvene, but instead its dimer, in good yield by deprotonation. These results indicate that the iminium perchlorate from pyrrole- and indolecarbaldehyde appears to be a convenient precursor of azafulvene.
Ethylation and Transethylation of Naphthalene
Authors: Shimada Keizo , Nagahama Shizuo 
Published: July 2006

Abstract
Transethylation of naphthalene by ethylxylenes and ethylbenzene in the presence of AlCl3 as a catalyst was studied and compared with ethylation by ethyl bromide. When ethylxylenes were used, it was observed that the β-isomer of ethylnaphthalene initially formed (96.8%) was isomerized to the α-isomer. This was attributed to steric hindrance of the α-position in the transition state of reactions proceeding by the hydride abstraction mechanism. However, the formation of considerable proportion of the α-isomer (25%) was observed in the case of transethylation by ethylbenzene, as well as of ethylation with ethyl bromide (60% α-isomer). Thus, the SN2 mechanism should be operative, at least partly, in the transethylation by ethylbenzene. The rates of transethylation by ethylxylenes were found to be in the order: 1,2-diMe-4-Et-\overset·\underset·≈1,3-diMe-4-Et-&gt;1,4-diMe-2-Et-&gt;&gt;1,3-diMe-5-5-Et-benzene. The equilibrium composition of ethylnaphthalene was found to contain 8.7–8.8% α-isomer.
Low-temperature NMR Studies of the Conformations of 3-Aryl-1,2,3-oxathiazolidine 2-Oxides
Authors: Yamada Fukiko , Nishiyama Tomihiro , Samukawa Hiroshi 
Published: July 2006

Abstract
A complete iterative NMR spectral analysis has been carried out for twelve 3-aryl-1,2,3-oxathiazolidine 2-oxides at several low temperatures over a range of 111 °C. The magnitudes of the two vicinal coupling constants either increased or decreased markedly with a decrease in the temperature. On the basis of the resulting vicinal coupling constants, the correlations between the ratios of the vicinal coupling constants and the corresponding torsion angles were obtained and made it possible to assign their twist-envelope conformations. From the experimental data, the parameters of the Karplus equation could be given:
Jvic=5.3-cos(135±θ)+4.3cos2(135±θ)
+45°≥θ≥-45°
Cyclic Dimerization of Ethyl 1-Arylethylidenecyanoacetates with Grignard Reagents
Authors: Hayashi Shoji , Anii Takami , Tamano Taizo 
Published: July 2006

Abstract
The treatment of ethyl 1-arylethylidenecyanoacetates (I) with Grignard reagents, especially mesitylmagnesium bromide, gave ethyl 2,4-diaryl-5-cyano-5-ethoxycarbonyl-6-imino-4-methyl-1-cyclohexenecarboxylates (II), a dimer of I.
Anomeric Effect Involving Carboxyl and Ethynyl Group in Sulfur-Containing Heterocycles
Authors: Arai Kazutaka , Iwamura Hiizu , Oki Michinori 
Published: July 2006

Abstract
Normal anomeric effect is found in 1,3-dithiane-2-carboxylic acid, 1,3,5-trithiane-2-carboxylic acid, and their esters, in contrast to a report that oxane-2-carboxylic acid derivatives exhibit reverse anomeric effect. The results are interpreted from the difference in bond lengths between oxanes and polythianes which affects the extent of 1,3-diaxial interaction. The anomeric effect is found to be larger in 1,3-dithianes than in 1,3,5-trithianes. The differences is discussed on the ground of the energy levels of available electrons. Phenylethynyl derivatives also show small but definite anomeric effect.
X-Ray Photoelectron Spectroscopy of EDTA—Metal Chelates
Authors: Yoshida Tooru , Sawada Shigemasa 
Published: July 2006

Abstract
Photoelectron spectra of metal chelates of ethylenediaminetetraacetic acid (EDTA) were measured. A nearly linear relationship holds between the chemical shifts of the N(ls) electron binding energies and the charge on the nitrogen atoms of the chelates, calculated by means of Pauling’s electronegativity concept.
The Catalytic Reduction of Nitric Oxide by Carbon Monoxide over a Fe2O3 Catalyst
Authors: Sugi Yoshihiro , Todo Naoyuki , Sato Toshio 
Published: July 2006

Abstract
When nitric oxide was admitted during the course of the reduction of N2O by CO, a discontinuous increase in the N2O pressure and a decrease in the NO pressure were observed. The reduction of N2O stopped completely, and only the reduction of NO to N2O proceeded.
Nuclear Magnetic Resonance Studies of Bicyclic Thiophene Derivatives. III. Through Space H–F Coupling over Seven Bonds
Authors: Hirohashi Toshiyuki , Inaba Shigeho , Yamamoto Hisao 
Published: July 2006

Abstract
Bicyclic thiophene derivatives, 1,5-dimethyl-(1) and 3,5-dimethyl-4-(o-fluorophenyl)-l,2-dihydrothieno[2,3-d]-pyrimidin-2-ones (3), 2-acetylamino-3-(o-fluorobenzoyl)-4-methylthiophene (5), and some derivatives (2, 4, 6, 7), have been prepared. 1H, 19F Spin couplings over seven bonds, 7JHF, attributable to a through-space mechanism have been observed in the 1H NMR spectra of these compounds.
Electronic Absorption Spectra of the Disulfone Radical Anion. Conjugative Effect of the Sulfone Group
Authors: Ito Osamu , Matsuda Minoru 
Published: July 2006

Abstract
Disulfone radical anions produced by γ-irradiation show a characteristic absorption band at a longer wavelength region (655–695 nm) than that of the monosulfone radical anion (ca. 400 nm). The former band is attributed to the charge-resonance originated from the delocalization of an unpaired electron between the linked two sulfone moieties.
Dipole Moments of the Iodine Compounds Complexed with Some Aliphatic Amines
Authors: Toyoda Koichi , Imai Motoo 
Published: July 2006

Abstract
The dipole moments of some iodine compounds complexed with some aliphatic amines in benzene solution were obtained: 6.81D for EtH2N–I2; 6.78D for Et2HN–I2; 6.72D for Me3N–ICl; 7.22D for Me3N–IBr; 6.46D for Me3N–ICN.
Reactions of Diazomethyl-1,3,5-triazines with Cyclohexane
Authors: Kumagai Akio , Sekiguchi Shizen , Matsui Kohji 
Published: July 2006

Abstract
Diazomethyl-1,3,5-triazines reacted with cyclohexane thermally and photochemically to give cyclohexylmethyl-1,3,5-triazines as the major product. The reactions took place via a carbene intermediate; however, the hydrogen abstraction products (methyl-triazines) were not obtained in these cases.
Iron Carbonyl-catalyzed Reactions of Allyl Ethers and Amines Involving Claisen-type Rearrangement
Authors: Kiji Jitsuo , Nishimura Satoshi , Yamamoto Kazuyoshi , Furukawa Junji 
Published: July 2006

Abstract
The iron carbonyl-catalyzed reaction of diallyl ether with morpholine gives 1,4-dienylamine. Diallylamine isomerizes to 4-aza-6-methyl-1,4-nonadiene.
The Fries Rearrangement of Acetoxybenzofuran Derivatives and the Synthesis of Furochromenonecarboxylic Acids
Authors: Nanbu Mutsumu , Yamaguchi Seiji , Sugimasa Yasuo , Miyaura Tatsuya , Kawase Yoshiyuki 
Published: July 2006

Abstract
The Fries rearrangement of 4-, 5-, 6-, and 7-acetoxy-2,3-dimethylbenzofurans was studied and the o-hydroxy-ketones obtained were converted to dimethylfuro derivatives of 4H-chromen-4-one-2-carboxylic acid.
An INDO Molecular-orbital Interpretation of the NMR of Several Protonated Heteroaliphatic Compounds
Authors: Ohkubo Katsutoshi , Tsughihashi Kohji , Yoshida Toshiaki , Okada Masahide 
Published: July 2006

Abstract
Several protonated alcohols, acids, and esters were investigated by means of the INDO-MO theory and in connection with their proton and carbon-13 NMR results. The relative stability of the protonated conformers as detected by the NMR spectroscopy, had a good coincidence with the MO-theory and the experimental results. The proton or carbon-13 chemical shifts and coupling constants also showed satisfactory linear correlations between the theory and the experiment; the proton and isotropic (13C) chemical shifts could be well explained by the linear correlation between the diamagnetic shielding constant and the electron density on the proton of the O–H bond and between the calculated paramagnetic shielding effect and the observed isotropic chemical shifts. The observed coupling constants of the proton and carbon-13 NMR had good overall parallelisms with those evaluated by means of the Fermi contact effect.
The Infrared Absorption Spectra of Nickel Metal Surfaces Modified with Optically Active α-Alanine from Its Aqueous Solution
Authors: Hatta Aritada , Moriya Yoshihiro , Suëtaka Wataru 
Published: July 2006

Abstract
The infrared absorption spectra of thin films of α-alanine formed on pure nickel and “Raney nickel” surfaces, modified with its aqueous solution, were measured by the high-sensitivity reflection method. From the infrared dichroism in the reflection spectra, the molecular orientations in the thin films were derived. In the thin film formed on pure nickel modified at 5 °C, the CO2− group of α-alanine is oriented nearly vertical to the metal surface and the O···O axis is inclined to the surface. On the other hand, when the “Raney nickel” film is modified at 5 °C, the Cα–Co(carboxylate) bond is oriented obliquely to the surface. When the “Raney nickel” film is modified at 100 °C, the Ni-alanine chelate is formed on the surface: the Cα–Co bond and the NH2 group are nearly parallel to the substrate surface, while the O···O axis is vertical to that surface.
The Adsorption of α- and β-Cyclodextrins on the Dropping Mercury Electrode in an Aqueous Solution
Authors: Matsui Yoshihisa , Sawada Hiroshi , Mochida Kazuo , Date Yoshio 
Published: July 2006

Abstract
The adsorption of α- and β-cyclodextrins on the surface of the dropping mercury electrode was examined in a phosphate buffer solution by means of voltammetry with a triangular potential sweep. The α- and β-cyclodextrins gave two capacitive peaks corresponding to the adsorption and desorption processes respectively. The α-cyclodextrin additionally gave two cathodic peaks and an anodic peak, probably due to reorientation processes. The effects on the peak heights were investigated in terms of the sweep rate, the cyclodextrin concentration, the temperature, the ionic strength, and the pH. The adsorption of both cyclodextrins followed the Langmuir isotherm, and the equilibrium constants for the adsorption were evaluated to be 1.2×104 M−1 for α-cyclodextrin and 1.0×105 M−1 for β-cyclodextrin at 25°C and pH 6.5.
The X-Ray Photoelectron Spectroscopy of o-Hydroxy Aromatic Azo Metal Complexes
Authors: Yoshida Tooru , Sawada Shigemasa 
Published: July 2006

Abstract
The photoelectron spectra of azo metal complexes were measured. There was no significant change in the profile or the binding energy of the N(ls) peak upon coordination. It was deduced that, in the bond between the azo-group and the metal, there is a contribution of a π-bonding.
Chemical Effects of 31P(n,γ)32P Reaction in Phosphate Glass—A Radiation Chemical Approach to Hot Atom Chemistry
Authors: Lin Tsing-Ko , Matsuura Niro 
Published: July 2006

Abstract
Sodium metaphosphate glass, with a polymerization degree of 50–100, was used as target material for the study of the chemical effects of (n, γ) reaction. Mean oxidation number of 32P was introduced as a new parameter to elucidate the oxidation reaction brought on the recoil product. The mean oxidation number of 32P from (n, γ) recoil in such glassy polyphosphate was about +4. More than 90% of the 32P set free was reattached as an end group in the newly formed radioactive polyphosphate. The recoiled monoatomic 32P species (less than 10% of the total 32P) defficient in oxygen kept a low mean oxidation number ca. +3. Ionizing radiation produced color center (with λmax at 510 nm) which seemed partially to oxidize the 32P product. The effect was very weak, and could be suppressed by the hold scavengers. Thermal annealing showed that the mean oxidation number of 32P rapidly attained +5 (the valence of target) by 300 °C; however, it seems very difficult to raise the mean oxidation number of 32P to +5 by γ-ray annealing. The oxidation of 32P through thermal annealing is considered to be a diffusion process, with an activation energy of ca. 7×103 cal/mol. Possible reaction between the hot-zone and the radiation spurs is discussed.
The Mechanism of Amine Sensitization of the Emission of Tris(dibenzoylmethano)europium(III)
Authors: Fukuzawa Tadashi , Ebara Nozomu , Katayama Mikio , Koizumi Hideaki 
Published: July 2006

Abstract
The mechanism of enhancement of emission quantum yield of the methanol solution of tris(dibenzoylmethano) europium (III) by triethylamine has been investigated. Lifetime of Eu3+ resonance emission of the chelate did not change remarkably when triethylamine was added. The aspect of temperature dependence of the emission intensity was similar for both the chelate itself and the chelate-amine adduct under direct excitation of the metal level, but differed under excitation of the ligand. It was suggested that the sensitization is mainly due to a suppression of nonradiative process in the ligand triplet state.
The Additions of Acetic Acid to Limonene over Solid Acid Catalysts
Authors: Yamanaka Tohr 
Published: July 2006

Abstract
The addition of acetic acid (AcOH) to limonene (IV) over 111–333 g/1 of solid acid catalysts, at 28–92 °C and in an excess of AcOH (19–100 times of IV in molarity), were studied in terms of the kinetic data, at a total conversion of IV less than 10 mol%, and in terms of acid strength distributions of the catalysts. In the reaction medium, a leveling of the acid strength on solids was observed. For the formation of α- and β-terpinyl acetates (I and II) and a mixture of the isomeric p-menthadienes (III) as by-products, (1) the rates are proportional to the square root of the initial concentrations of IV; (2) the apparent activation energies are 18.3 kcal/mol for all the catalysts, and (3) the pre-exponential factors are roughly proportional to the square root of the highest acidity (h0,max) of the catalyst surface in the medium. The effects of the acid properties of the catalyst on the catalytic activity and the selectivity are different from those in a homogeneous liquid acid-catalyst system.
A Temperature-Jump Study of Electron-Transfer Reactions Involving Ion Radicals: Reactions of the Cation Radicals of Phenothiazine and Aromatic p-Diamines
Authors: Yamagishi Akihiko 
Published: July 2006

Abstract
The reversible one-electron-transfer reactions of the following cation radicals were studied by temperature-jump and stopped-flow methods: phenothiazine (PhZ)/N,N,N′,N′-tetramethyl-p-phenylenediamine cation (TMPD\underset.+), PhZ/N,N-dimethyl-p-phenylenediamine cation (DMPD\underset.+), DMPD/TMPD\underset.+ and DMPD/N,N,N′,N′-tetramethylbenzidine cation (TMBZ\underset.+). The solvent used was either 1 : 3 ethanol-water or acetonitrile. For PhZ/TMPD\underset.+, PhZ/DMPD\underset.+ in ethanol-water and also for DMPD/TMPD\underset.+ in acetonitrile, the backward reaction corresponding to the negative free energy change of reaction (ΔF°&lt;0) proceeds almost at the diffusion controlled rate. The backward rate constant for DMPD/TMPD\underset.+ in ethanol-water, (6±1)×108 M−1 s−1, is slightly less than a diffusion controlled one even for ΔF°&lt;0. The results are discussed as compared with the previous study on 7,7,8,8-tetracyanoquinodimethane/substituted-p-benzoquinone anions.
Stability Constants of Several Aliphatic Uranyl Carboxylates
Authors: Kim Bong-il , Miyake Chie , Imoto Shosuke 
Published: July 2006

Abstract
The stability constants of uranyl carboxylates were determined spectrophotometrically; for butyrate, they were logK1=2.96, logK2=2.66, logK3=2.43, and logK4=2.23; for isobutyrate, logK1=2.74, logK2=2.20, and logK3=1.66; for valerate, logK1=2.91, and logK2=2.52, and for isovalerate, logK1=2.90 and logK2=1.91.
Solution Properties of Phycocyanin. III. Studies of the Sedimentation Equilibrium of Phycocyanin
Authors: Mizuno Haruo , Saito Takahide , Iso Naomichi 
Published: July 2006

Abstract
The dissociation-association behavior of phycocyanin has been studied by sedimentation-equilibrium measurements under various pH and ionic-strength conditions. The weight-average molecular weight of phycocyanin changed according to the changes in concentration of the solute. From the concentration dependence of the molecular weight, it has been claimed that the dissociation-association equilibrium system of phycocyanin is trimer\ightleftharpoonsmonomer at pH 6.8 in the relatively low concentration region and hexamer\ightleftharpoonsmonomer at pH 5.4. However, the coexistence of the trimer\ightleftharpoonsmonomer and hexamer\ightleftharpoonsmonomer systems is in evidence in the concentration region larger than 0.06 g/dl. This dissociation-association behavior of phycocyanin is supported by the experimental results obtained from sedimentation-transportation and osmotic-pressure measurements.
Long-range Interaction between a Hydrogen Atom and a Hydride Ion
Authors: Yamabe Tokio , Tanaka Kazuyoshi , Ueno Hiroshi , Fukui Kenichi 
Published: July 2006

Abstract
The long-range force between a hydrogen atom and a hydride ion has been studied by means of the second-order perturbation theory. This H–H− system has been chosen as the simplest example of a system composed of a neutral atom and an anion. The results seem to suggest that the analytical closed form of the second-order energy is desirable for any discussion of the long-range interaction between H and H− in place of the usual multipole expansion. According to the multipole expansion until the R−12 term, the nature of the long-range interaction operating in this system seems to be dispersive, and it seems to become inductive at a much larger R because of the existence of the leading R−4 term.
Tantalum Carbide Formed by the Carbonization of Ta2O5 in an Argon Plasma Arc
Authors: Matsumoto Osamu , Saito Michio 
Published: July 2006

Abstract
The formation of tantalum carbide by the carbonization of Ta2O5 with graphite by heating in an argon plasma arc was studied. Chemical and X-ray analyses showed that the product obtained was either stoichiometric or a defect carbide with the formula of TaC1−X. The products were found to be superconductors.
The Formation of the Rhodium Carbonyl Complexes from Chlorotris-[triphenylphosphine]rhodium with Alcohols in the Presence of Diene and Olefin
Authors: Yamada Akira , Fukuda Takashi , Yanagita Masaya 
Published: July 2006

Abstract
The decarbonylation of alcohols using chlorotris[triphenylphosphine]rhodium in the presence of diene or olefin occurs with the formation of the rhodium carbonyl complex and a hydrocarbon originating from the alcohol. The most suitable reaction system is rhodium compound/methanol/butadiene. The results suggest catalysis by a rhodium species.
The Inductive Susceptance Observed with Electrode Reaction of Water at Far Negative Potentials
Authors: Takahashi Katsuo , Matsuda Kiyoshi , Tamamushi Reita 
Published: July 2006

Abstract
The admittance of various electrodes/dilute aqueous electrolyte solution systems was measured at far negative potentials in the frequency range of 22–500 Hz, and the experimental results were discussed in terms of the mechanism of the electrochemical reduction of water molecules. The frequency dependence of the conductance- and susceptance-components was analyzed by assuming possible equivalent circuits. It was concluded that, in the systems which give inductive susceptances at low frequencies, the reduction of water proceeds according to the electrochemical mechanisms;
H_2O+e→H_ad+OH^-, H_ad+H_2O+e→H_2+OH^-
where the current density due to the second reaction path is proportional to the product of θ and (1–θ), θ being the coverage of the electrode surface by adsorbed hydrogen atoms, Had. At some metal electrodes in solutions of alkali-metal cations, no inductive susceptance was observed; this suggests that the hydrogen evolution proceeds according to other mechanisms.