bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reforming of Ethanol –Dehydrogenation to Ethyl Acetate and Steam Reforming to Acetic Acid over Copper-Based Catalysts–
Authors: Iwasa Nobuhiro , Takezawa Nobutsune 
Published: July 2006

Abstract
The title reactions, 2CH3CH2OH→CH3COOC2H5+2H2 and CH3CH2OH+H2O→CH3COOH+2H2, were carried out over copper-based catalysts (Cu, Cu/SiO2, Cu/ZrO2, Cu/Al2O3, Cu/MgO, and Cu/ZnO). The selectivities to ethyl acetate and acetic acid markedly depended upon the supports used. Acetaldehyde was formed by the dehydrogenation of ethanol and transformed to either ethyl acetate or acetic acid through steps in which a nucleophilic addition of ethanol (or ethoxide ions) or water (or hydroxide ions) to acetaldehyde occurred. The rates of the transformation steps to ethyl acetate and acetic acid were appreciably affected by the kinds of supports used. The transformation steps proceeded slowly, compared with the dehydrogenation step.
Effect of Oxidants on the Oxidative Coupling of Methane over a Lead Oxide Catalyst
Authors: Asami Kenji , Shikada Tsutomu , Fujimoto Kaoru 
Published: July 2006

Abstract
Oxidative coupling of methane was studied over a PbO/MgO catalyst using a variety of oxidants such as N2O, NO, CO2, and SO2. While N2O showed both high activity and selectivity for the title reaction, NO produced CO2, exclusively. The coupling reaction was assumed to proceed via the redox cycle of Pb and PbO on each oxidant mentioned above. Carbon dioxide produced small amounts of C2 hydrocarbons and CO, while SO2, was inactive for the reaction. Oxygen, N2O, CO2 could oxidize the Pb/MgO which had been formed by the reaction of PbO/MgO with methane at 1023 K. Thus-prepared PbO/MgO produced C2 hydrocarbons from methane. Even NO, which gave no C2 hydrocarbons in the CH4–NO cofeed reaction, converted the Pb/MgO to PbO/MgO and the PbO/MgO gave C2 hydrocarbons exclusively upon reacting with CH4. NO seems to oxidize the methyl radical, which is an intermediate of the coupling reaction to CO2. The ineffectiveness of SO2 as an oxidant was attributed to the formation of PbS, which is inactive in the methane activation.
Solvatochromic Shift of Aromatic Ketyl Anions due to Hydrogen Bonding
Authors: Ichikawa Tsuneki , Ueda Ken-ichi , Yoshida Hiroshi 
Published: July 2006

Abstract
The electronic spectra of fluorenone radical anions generated by γ-irradiation at 77 K in glassy matrices of ethanol and ethanol–2-methyltetrahydrofuran mixtures have been measured for elucidating the mechanism of the spectral change due to solvation of the radical anions by alcohols. Three kinds of the radical anions are generated in the mixed solvent: the radical anions without hydrogen bond (ε=1.05×104 dm3 mol−1 cm−1 at λmax=568 nm), with one ethanol molecule (ε=0.67×104 dm3 mol−1 cm−1 at λmax=529 nm) and two ethanol molecules (ε=0.37×104 dm3 mol−1 cm−1 at λmax=448 nm) hydrogen-bonded through the π electron on the carbonyl oxygen. The spectral shift and the decrease of the molar extinction coefficient of aromatic ketyl radical anions are explained as due to the stabilization of a carbonyl antibonding n orbital by hydrogen bonding.
Surface and Subsurface Fluorometry under Normal Incidence Conditions
Authors: Wu Xing-Zheng , Kitamori Takehiko , Teramae Norio , Sawada Tsuguo 
Published: July 2006

Abstract
Laser induced fluorescence spectroscopy under normal incidence conditions has been applied to a thick film sample, and identification of surface and subsurface fluorescent components was demonstrated. A model film sample adsorbing different fluorescent compounds on its two sides was prepared. Fluorescence spectra from the surface and subsurface regions were separately obtained for observation angles larger and smaller than the critical angle, and it was shown that the same information as the conventional attenuated total reflection method can be obtained with the normal incidence conditions, which is anticipated by the reciprocal principle. Dependence of fluorescence intensity on observation angle agreed well with theoretical calculation results based on the reciprocal principle, which supports the methodology propriety.
Characteristics of Suspended Ru/Carbon Catalyst for 2-Propanol Dehydrogenation Applicable to Chemical Heat Pump
Authors: Yamashita Masaru , Kawamura Tokiji , Suzuki Minoru , Saito Yasukazu 
Published: July 2006

Abstract
Liquid-phase dehydrogenation of (CH3)2CHOH, (CH3)2CHOD and (CH3)2CDOH was performed at 82.4 °C with high activity and selectivity under refluxing conditions by heating the suspended solution at 100 °C with a carbon-supported ruthenium catalyst. Since the mixture of (CH3)2CHOH and (CD3)2CO(10 vol%) gave 2-propan-1,1,1,3,3,3-d6-ol at a rate 7.15-times higher than that of hydrogen evolution, hydrogen transfer from 2-propanol to acetone ought to proceed simultaneously with dehydrogenation. Relatively small kinetic isotope effects of 1.69 and 1.57, obtained from (CH3)2CHOD and (CH3)2CDOH, respectively, on the Ru/carbon catalyst for dehydrogenation, suggests that the slowest step is not a splitting of the methine C–H bond but, rather, the formation of molecular hydrogen from surface hydrogen species. Further improvements regarding easy desorption of both acetone and hydrogen are necessary for the catalyst most suitable for 2-propanol dehydrogenation in a chemical heat pump system.
Photochemical Reactions of Vinyl-, Styryl-, and Benzyl- Substituted Digermanes
Authors: Mochida Kunio , Kikkawa Haruhiko , Nakadaira Yasuhiro 
Published: July 2006

Abstract
Photochemical reactions of vinyl-, styryl-, and benzyl-substituted digermanes were investigated by chemical trapping experiments. Photolysis of vinylpentamethyldigermane afforded 1-trimethyl-2-(pentamethyldigermyl)ethane as a major product, and styrylpentamethyldigermanes gave mainly styryltrimethylgermane. On the other hand, photolysis of benzyl-substituted digermanes (benzylpentamethyldigermane and 1,2-dibenzyltetramethyldigermane) gave hydrogermanes and hydrodigermanes as main products, respectively. These products were derived from germyl radicals generated by photoinduced homolysis of the germanium–germanium bond. In carbon tetrachloride (CCl4), these germyl radicals were converted to the corresponding chlorogermanes by abstraction of a chlorine atom. Germylene species were also to be evolved from such photolyses.
Synthetic Photochemistry. LVII. Facile Photochemical Construction of Hexahydro-as-indacene Skeleton, a Carbon Framework of Ikarugamycin, from High-Pressure Diels–Alder Adducts of Tropones–Cyclopentenone
Authors: Li Zhi-Hong , Mori Akira , Kato Nobuo , Takeshita Hitoshi 
Published: July 2006

Abstract
The high-pressure Diels–Alder reaction of tropones with 2–cyclopenten-1-one afforded isomeric mixtures of adducts. Upon UV irradiation, these adducts isomerized to hexahydro-as-indacene, via [1,3] acyl migration, and tetracyclo[7.3.0.03,7.06,8]undecene derivatives through a ketene intermediate via a di-π-methane rearrangement. The former tricyclic system corresponds to the carbon skeleton of ikarugamycin. An “exo [6+4] adduct” of tropone and 1,4-cyclopentadien-1-ol, an enol form of 2-cyclopentenone, was obtained as a by-product.
High-Pressure Fourier Transform Infrared Spectroscopy Study of the Diels–Alder Reaction of Isoprene and Maleic Anhydride in Supercritical Carbon Dioxide
Authors: Ikushima Yutaka , Saito Norio , Arai Masahiko 
Published: July 2006

Abstract
A high-pressure FTIR spectroscopy was used to make an in situ study on the Diels–Alder reaction of isoprene and maleic anhydride catalyzed with aluminum chloride in supercritical carbon dioxide at 306 K and 7.45 and 7.85 MPa, suggesting a two-step mechanism and showing a pressure effect.
Dielectric Properties of Poly(methylphenylsilylene) under Humidity in the Kilohertz Range
Authors: Awano Hiroshi , Iwai Takayoshi , Ohigashi Hiroji 
Published: July 2006

Abstract
The capacitance and dielectric loss tangent of poly(methylphenylsilylene) thin films were measured under various humidities over the frequency range 0.1–1000 kHz. In the high-humidity range, both the quantities increase with decreasing frequency. The existence of an anomalously low-frequency relaxation (lower than 0.1 kHz) is suggested in which the adsorbed water molecules are involved.
Glucose-Sensing Electrode Based on Carbon Paste Containing Ferrocene and Polyethylene Glycol-Modified Enzyme
Authors: Mizutani Fumio , Yabuki Soichi , Okuda Atsushi , Katsura Tatsuo 
Published: July 2006

Abstract
An amperometric glucose-sensing electrode is constructed by the use of a carbon paste containing 1,1′-dimethylferrocene and a polyethylene glycol-modified glucose oxidase. The polymer-modified enzyme is soluble in organic solvents (e. g., hexane) as well as in water, and exhibits a much higher activity than native enzyme does on the surface of a hydrophobic carbon paste eletrode. The higher enzyme activity results in an enhanced electrode response: the current response to glucose on the modified enzyme-based electrode is several times as large as that obtained on a native enzyme-based electrode.
Photoinduced Cyclization of 2-Acetonyl-3-alkoxy-1,4-naphthoquinones: Formation of 2-Alkyl-Substituted 4-Methylnaphtho[2,3-d]-1,3-dioxepin-6,11-diones
Authors: Nakagawa Katsuhiko 
Published: July 2006

Abstract
Irradiation of 2-acetonyl-3-alkoxy-1,4-naphthoquinones in benzene gave 2-alkyl-substituted 4-methylnaphtho[2,3-d]-1,3-dioxepin-6,11-dione and 2-acetonyl-3-hydroxy-1,4-naphthoquinone via intramolecular hydrogen-abstraction reaction. Irradiation of quinones in methanol, however, gave the latter product exclusively.
The Synthesis and Thermal Reorganization of Lithium Heptasodium cyclo-Octaphosphate
Authors: Watanabe Makoto , Honda Tomohiko , Furuta Shinsaku 
Published: July 2006

Abstract
Lithium heptasodium cyclo-octaphosphate hexahydrate, LiNa7P8O24·6H2O, has been prepared by heating lead cyclo-tetraphosphate tetrahydrate at 340°C for 20 min, dissolving the thermal product in a 3% aqueous solution of tetrasodium ethylenediammetetraacetate, and then crystallizing by the addition of lithium chloride and methanol to the solution. When the cyclo-octaphosphate was heated above 180°C, it decomposed to produce phosphates with chain lenghts shorter and longer than that of the cyclo-octaphosphate. The thermally produced phosphates were reorganized to sodium cyclo-triphosphate and a small amount of insoluble polyphosphates by heating at about 300 to 350°C. The phosphates melted at about 620°C.
Synthesis and Fluorescence Properties of Selectively Metallated Diporphyrins with Electron-Accepting Moieties
Authors: Nagata Toshi 
Published: July 2006

Abstract
Synthesis of selectively metallated diporphyrins with electron-accepting moieties is described. Steady-state fluorescence spectra of these compounds snowed substantial quenching of the fluorescence of the free-base porphyrin. A possible “superexchange” mechanism of long-range electron transfer is discussed.
Hydrates of Organic Compounds. XVI. Determination of the Melting Points and Hydration Numbers of the Hydrates of Tetrabutyl(or Tetraisopentyl)ammonium Alkanesulfonates
Authors: Nakayama Haruo , Yamanobe Masashi , Baba Kei 
Published: July 2006

Abstract
The solid-liquid phase diagrams of binary mixtures of water with tetraisopentylammonium alkanesulfonates, [(i-C5H11)4N][n-CnH2n+1SO3] (n=1–8), bis(tetrabutylammonium) alkanedisulfonates, [(n-C4H9)4N]2[O3S(CH2)nSO3](n=2–5), and with bis(tetraisopentylammonium) alkanedisulfonates, [(i-C5H11)4N]2[O3S(CH2)nSO3] (n=2–5), were examined in order to confirm the formation of hydrates. For all of the sulfonates examined the formation of hydrates has been newly confirmed. The hydrates of the tetraisopentylammonium alkanesulfonates have hydration numbers of around 37–40 and fairly high melting points (lie between 13 and 19°C). The typical hydrates formed by the bis(tetrabutylammonium) alkanedisulfonates have hydration numbers of around 52 and those by the bis(tetraisopentylammonium) alkanedisulfonates around 76. The former disulfonate hydrates have low melting points (between 1.0 and 10°C). However, the latter disulfonate hydrates have fairly high melting points (between 13 and 18°C). A salt with n=4 forms the most stable hydrate for both series of alkanedisulfonates. Judging from the hydration numbers and melting points, these hydrates seem to be clathrate-like.
A Further Modification of the Born Equation
Authors: Abe Takehiro 
Published: July 2006

Abstract
By considering the distance-dependent relative permittivity of a solvent, the Born equation has been modified for a diatomic ion in which the charge is located on an atom deviating from the center of a spherical cavity. The new equation has been successfully applied to the diatomic ions of OH−, SH−, and CN−.
Structural, Magnetic, and Spectroscopic Characterization of the Pyridine Complexes of Copper(II) Triphenylacetate: A Dimeric Copper(II) Triphenylacetate–Pyridine Complex with Distorted Trigonal Bipyramidal Geometry Around Copper
Authors: Steward Omar W , Kato Michinobu , Chang Shih-Chi , Sax Martin , Chang Chong-Hwan , Jury C Frederick , Muto Yoneichiro , Tokii Tadashi , Taura Toshiaki , Pletcher James F , Yoo Chung Soo 
Published: July 2006

Abstract
The synthesis and characterization of three copper(II) triphenylacetate-pyridine complexes are reported along with their magnetic and spectral properties: [Cu2(O2CCPh3)4(py)2]·C6H6 (1), [Cu2(O2CCPh3)4(py)2] (2), and Cu(O2CCPh3)2·2py (3). Crystal structure analyses of 1 and 3 have revealed unusual geometries around copper: 1, triclinic, space group P\bar1 with a=19.558(7) b=16.605(6), c=14.997(5) Å, α=14.55(2)°, β=97.11(2)°, γ=111.65(2)°, and Z=2; 3, monoclinic, space group P21⁄c with a=8.931(1), b=12.602(1), c=19.578(1) Å, β=118.17(0.4)°, and Z=2. The coordination sphere around each copper in the dimeric complex 1 is a highly distorted trigonal bipyramid with bridging triphenylacetato ligands spanning the apical and equatorial positions, resulting in a long Cu–Cu distance of 3.086(1) Å. Temperature-dependent magntic susceptibility measurements on 1 indicate that the two coppers are antiferromagnetically coupled with −2J=187 cm−1. The structure of the monomeric complex 3 is unusual in that the out-of-plane carboxylate oxygen is twisted 12° from the normal. Two solid modifications are observed for 2. The magnetic and spectral properties of 2a (−2J=173 cm−1) resemble those of 1, and 2b (−2J=321 cm−1) those of copper(II) acetate monohydrate. Magneto-structural correlations are presented. The novel structural features of these complexes are suggested to arise from steric effects resulting from the spatial relationships both between and within the molecules in the crystal environment.
Chromium(VI) Complexation with Triisooctylamine in Organic Solvents
Authors: Huang Yaou-Huei , Chen Chuh-Yung , Kuo Jen-Feng 
Published: July 2006

Abstract
Liquid–liquid extraction of chromium(VI) from chromic acid solutions with triisooctylamine (tris(6-methylheptyl)amine, abbrev. to TIOA) dissolving in various organic solutions has been studied. The reaction between chromium(VI) and TIOA in o-xylene has been discussed in detail. It has been found that dichromate ion and hydrogen chromate ion coexist in the system, based on the extraction data and the IR and UV-visible spectra of the TIOA-chromium salt. The chromium extraction equilibria can be expressed as:
‾TIOA+H++HCrO4−\ightleftarrows‾(TIOAH)HCrO4
2‾TIOA+2H++CR2O72\ightleftarrows‾(TIOAH)2CR2O7
The extraction constants are obtained.
Spectrophotometric Determination of Trace Amounts of Selenium Based on Catalytic Reduction of Toluidine Blue by Sulfide Ion
Authors: Parham Hooshang , Shamsipur Mojtaba 
Published: July 2006

Abstract
A simple, rapid, and sensitive kinetic method for the determination of trace selenium (0.03–1.5 μg cm−3) based on its catalytic effect on the reduction reaction of toluidine blue and sodium sulfide is reported. The reaction is monitored spectrophotometrically by measuring the decreasing absorbance of toluidine blue at 605 nm by the variable time method. The detection limit is 8 ng cm−3 and the relative standard deviation for 1 μg cm−3 selenium is 1.4%. The procedure was successfully applied to the determination of selenium in real samples.
Oxidation of Primary Alcohols over Hydrous Zirconium(IV) Oxide
Authors: Kuno Hideyuki , Shibagaki Makoto , Takahashi Kyoko , Matsushita Hajime 
Published: July 2006

Abstract
The oxidation of primary alcohols with quinone or benzophenone was carried out by catalysis with hydrous zirconium(IV) oxide in both batch and flow reaction systems. As a result, it was elucidated that a lot of primary alcohols can be efficiently oxidized over hydrous zirconium(IV) oxide.
Disproportionation of Carbon Monoxide on the Surface of Titanium and Vanadium Clusters
Authors: Srivastava Arun Kumar , Tewari Kamla Kant , Kojima Isao 
Published: July 2006

Abstract
In the framework of CNDO (Complete Neglect of Differential Overlap method) VOIP (Valance Orbital Ionization Potential) has been evaluated using the method of Anno and Sakai and for exchange integrals Wolfsberg–Helmholtz approximation has been used. The method has been used for studying the disproportiontion of carbon monoxide on titanium and vanadium clusters having two atoms respectively. A large number of theoretical models were designed, based upon various mechanistic possibilities. The bond energies between different atoms have been plotted against the distance, for the purpose of studying the formation and desorption of CO2. The present studies suggest that the disproportionation of CO on titanium cluster may follow a dissociative path while in case of vanadium cluster this reaction may follow a disproportionation, where disproportionation involves a reaction between a ‘bridge site’ adsorbed CO molecule with a gas phase CO molecule.
Effect of Proteins on the Zeta Potential of Dispersed Vesicular Globules in W/O/W Emulsions
Authors: Ueda Koichi , Matsumoto Sachio 
Published: July 2006

Abstract
The zeta potential of dispersed vesicular globules in W/O/W emulsions was found to be reduced systematically at neutral pH by increasing the isoelectric point of proteins immobilized in the inner aqueous phase of the globules. We considered the effect of proteins on the total interactions between vesicular globules.
1H and 13C NMR Relaxation Study of Iron(III) Tetraphenylporphyrin–Imidazole Complexes
Authors: Yamamoto Yasuhiko , Nanai Norishige , Chûjô Riichirô , Inoue Yoshio 
Published: July 2006

Abstract
1H and 13C nuclear relaxation of paramagnetic iron(III) tetraphenylporphyrin–imidazole complexes has been investigated in order to gain insight into the relationship between the paramagnetic relaxation rate and the electron-nucleus distance. The analysis of the nuclear spin–lattice relaxation time (T1) in terms of the distance indicated that, for the iron porphyrin complexes used, the contribution of the electron-nucleus dipolar coupling no longer contributes significantly to the relaxation process of a proton located at more than 0.75 nm away from the iron. For the complexes studied, the electron spin–lattice relaxation time (T1e) of 6.4 ps was calculated from the T1 values measured at 26°C.
Thermal Decomposition Studies on Amine Complexes of Copper(II) Nitrate in Solid State
Authors: Mathew Suresh , Nair C G R , Ninan K N 
Published: July 2006

Abstract
Thermal decomposition of tetraamminecopper(II) nitrate and bis(ethylenediamine)copper(II) nitrate has been studied using TG, DTG, and DTA. The kinetic parameters for the thermal deamination of the former were evaluated. The thermal decomposition of bis(ethylenediamine)copper(II) nitrate involves the concurrent deamination and the oxidation of the liberated amine by the decomposition products of Cu(NO3)2.
Estimation of Angles between the Ground- and Excited-State Dipole Moments from Solvent Spectral Frequency Shifts
Authors: Abe Takehiro 
Published: July 2006

Abstract
A method for estimating the angle between the ground- and excited-state dipole moments is presented on the basis of Abe’s improved expressions for the solvent frequency shifts of absorption and fluorescence spectra (Bull. Chem. Soc. Jpn., 54, 327 (1981); 58, 3415 (1985); 61, 3797 (1988)). Applications of the method to N,N-dimethylaniline and aniline give angles of 39.5° and 40.0°, respectively; the excited-state dipole moments are both smaller than the corresponding ground-state dipole moments.
Asymmetric Transformations of Proline and 2-Piperidinecarboxylic Acid via Formation of Salts with Optically Active Tartaric Acid
Authors: Shiraiwa Tadashi , Shinjo Kazuyuki , Kurokawa Hidemoto 
Published: July 2006

Abstract
The rates of racemization of optically active proline [Pro] and 2-piperidinecarboxylic acid [Pia] by using aldehydes as a catalyst tended to increase with a decrease in the acidity of the carboxylic acid used as solvent. Based on these results, the asymmetric transformations of Dl-Pro and (RS)-Pia were carried out via formation of salts with (2R, 3R)-tartaric acid to give optically pure l-Pro in over 80% yield and (R)-Pia in 70% yield. The asymmetric transformation of l-Pro was more successfully achieved by using (2S, 3S)-tartaric acid to give optically pure d-Pro in 85% yield based on the starting l-Pro.
Synthesis of Allyl 3-Deoxy-d-manno-2-octulopyranosidic Acid 4- and 5-Phosphates
Authors: Fukase Koichi , Kamikawa Takashi , Iwai Yukari , Shiba Tetsuo , Rietschel Ernst Theodor , Kusumoto Shoichi 
Published: July 2006

Abstract
Allyl glycosides (ketosides) of pyranosidic 3-deoxy-d-manno-2-octulosonic acid (Kdo), phosphorylated at either positions 4 or 5 were synthesized with the aim to study the biological properties of phosphorylated Kdo. The α and β-allyl glycosides prepared from a pyranosidic fluoride of diisopropylidene Kdo were protected at the 7- and 8-positions, and then O-phosphorylated at the 4- or 5-position by the phosphoramidite procedure. Separation of the positional isomers followed by deprotection afforded four compounds in pure states.
Preparation of New Nitrogen-Bridged Heterocycles. 28. First Syntheses of 1,3-Oxazino[6,5-b]indolizine Derivatives
Authors: Kakehi Akikazu , Ito Suketaka , Sakurai Tosio , Urushido Kunio , Hatanaka Susumu , Sugiura Kouji 
Published: July 2006

Abstract
The reactions of 2-[mercapto(methylthio)methylene]-2(3H)-indolizinones with alkyl isothiocyanates in the presence of potassium t-butoxide in N,N-dimethylformamide afforded new heterocycles, 3-alkyl-2H-1,3-oxazino[6,5-b]indolizine-2,4(3H)-dithione derivatives, in moderate yields. On the other hand, their reactions with phenyl isothiocyanate did not afford the corresponding 2H-1,3-oxazino[6,5-b]indolizine-2,4(3H)-dithiones, although the reaction of 2-[mercapto(methylthio)methylene]-1-methyl-2(3H)-indolizinone with phenyl isothiocyanate gave 10-methyl-3-phenyl-2-phenylimino-2,3-dihydro-4H-1,3-oxazino[6,5-b]indolizine-4-thione in a very low yield (10%). The structures of these 2H-1,3-oxazino[6,5-b]indolizine-2,4(3H)-dithiones and the 2-phenylimino analogue were determined by inspections of their physical and spectral data and by a single crystal X-ray analysis of one of these compounds.
Stereoselectivity in the Hydrogenation of 4-t-Butylcyclohexanone with Catalytically-Active Powder Electrodes
Authors: Senda Yasuhisa , Tateoka Minako , Itoh Hiroki , Ishiyama Jun-ichi 
Published: July 2006

Abstract
The electrocatalytic hydrogenation of the title compound was examined over Raney Ni, Raney Co, Pt-carbon and Pd-carbon as hydrogen-active powder electrodes. A high conversion of ketone to alcohol was observed on the Raney catalysts when the pKa values of the proton sources employed were around 5. The metal-on-carbon catalysts showed a relatively low conversion of ketone regardless of the proton sources. The stereochemistry of the reaction was examined.