bluuebunny/crossref_metadata_2025_split huggingface dataset:
Generalized Graph-theoretical Formula for London Diamagnetism
Authors: Aihara Jun-ichi 
Published: July 2006

Abstract
The previous graph-theoretical formula for London diamagnetism was improved so as to include all kinds of cyclic conjugated systems. Bicyclo[6.2.0]decapentaene was then found to be diatropic but antiaromatic even though the central π bond was elongated.
The Transition-metal Catalyzed Dehalogenation of Aromatic Halides by NaOH–Alcohols. A Facile Method of Destroying Aromatic Polyhalides
Authors: Okamoto Tadashi , Oka Shinzaburo 
Published: July 2006

Abstract
Aromatic halides are dehalogenated by heating with NaOH in alcoholic solvents in the presence of transition metal salts, such as rhodium(III) chloride or palladium(II) acetate and triphenylphosphine. Bis(pentabromophenyl) ether was converted into diphenyl ether in 2-propanol when treated for 5 h at 355 K with a catalytic cycle of more than 80.
Neutron Diffraction Study of Aqueous Hydrochloric and Hydrobromic Acid Solutions
Authors: Ohtomo Norio , Arakawa Kiyoshi , Takeuchi Makoto , Yamaguchi Toshio , Ohtaki Hitoshi 
Published: July 2006

Abstract
The structure factors Sm(Q) over a wide range of Q(1.7–25 Å−1) for aqueous solutions of DC1 and DBr (ca. 1 M) at room temperature have been determined by means of LINAC-TOF neutron diffraction. The intramolecular structures of D2O and D3O+ in the solutions are found to be identical with those in the “revised watery model” for water. Applying the subtraction method of analysis to diffraction data for the solutions, we have obtained the following results with respect to the structure of the nearest hydration shell around ions in the DCl and DBr solutions: (a) D3O+ is tetrahedrally coordinated with four water molecules and Cl− and Br− are octa-hedrally coordinated with six ones, (b) the O–O distances between the central oxygen atom and that of hydrated water molecules for D3O+ are 2.88±0.05 Å, (c) the anion-oxygen distances are 3.10±0.05 Å for Cl− and 3.21±0.05 Å for Br−, and (d) around cations (D3O+) water molecules take the configuration to orient the axis of one of the two lone-pair hybrids on a straight line joining an oxygen atom and the cation, while around anions (Cl− and Br−) those take the configuration to orient the vector which bisects the D–O–D angle on a straight line joining an oxygen atom and the cation.
Determination of Hyperoxide in Dimethyl Sulfoxide by Photometric Titration with Iodine
Authors: Kitamura Katsumi , Hasegawa Koichi , Mochizuki Katsura , Imamura Taira , Fujimoto Masatoshi 
Published: July 2006

Abstract
The concentration of hyperoxide, O2−, in dimethyl sulfoxide (DMSO) was determined by photometric titration with iodine. The validity of the method was confirmed on the basis of stoichiometry by use of the standardized hyperoxide solution in the reaction of the complex, MoO(tpp)NCS, with methanol, where TPP denotes α,β,γ,δ-tetraphenylporphyrin.
The Cycloaddition of Nitrilimines with 1,2-Dibenzoylethylenes
Authors: Oida Tatsuo , Shimizu Tomio , Hayashi Yoshiyuki , Teramura Kazuhiro 
Published: July 2006

Abstract
The cycloaddition of nitrilimines with 1,2-dibenzoylethylenes gave an unexpected 1,3-diaryl-4-benzoylpyrazole and benzoic acid, along with an expected cycloadduct, 1,3-diaryl-4,5-dibenzoyl-2-pyrazoline, and its dehydrogenated product, 1,3-diaryl-4,5-dibenzoylpyrazole. The elimination of the benzoyl group from the pyrazoline followed by dehydrogenation was shown to be the course of the unusual reaction.
Esterification of Carboxylic Acids by Alcohols with 2-Chloro-1,3,5-trinitrobenzene as Condensing Agent
Authors: Takimoto Seiji , Inanaga Junji , Katsuki Tsutomu , Yamaguchi Masaru 
Published: July 2006

Abstract
When mixtures of carboxylic acids or their sodium salts and alcohols were treated with 2-chloro-1,3,5-trinitrobenzene in the presence of pyridine under mild conditions, the corresponding carboxylic esters were formed. The yields and the rates of the ester formation depended on the types of the acids and the alcohols used.
The Magnetic Circular Dichroism of the Conjugated O- and S-Heterocycles
Authors: Igarashi Nobuko , Tajiri Akio , Hatano Masahiro 
Published: July 2006

Abstract
The MCD spectra of the monobenzo and dibenzo derivatives of thiophene and furan are reported; especially in dibenzofuran, two electronic origins are revealed in its lowest energy absorption band. The quantum-mechanical calculations of the transition energies and the Faraday parameters elucidate the experimental data to a fair extent, suggesting similarities in the electronic structures of the lower-lying excited states of furan and thiophen derivatives.
Structure of the Complex of Neodymium Nitrate with Pentaethylene Glycol
Authors: Hirashima Yoshiyuki , Kanetsuki Koji , Shiokawa Jiro , Tanaka Nobuo 
Published: July 2006

Abstract
Crystals of the complex, Nd(NO3)3–HO-(CH2CH2O)5H, are monoclinic. The Nd atom is coordinated by ten oxygen atoms, four from two bidentate nitrate ions and six from a pentaethylene glycol. The pentaethylene glycol forms a ring-like structure similar to that of crown compounds.
Synthesis and Reactions of Perylenecarboxylic Acid Derivatives. X. Synthesis of N-Alkyl-3,4-perylenedicarboximide
Authors: Nagao Yukinori , Misono Takahisa 
Published: July 2006

Abstract
N-Alkyl-3,4-perylenedicarboximides (alkyl=methyl, ethyl, propyl, butyl, isobutyl, pentyl, hexyl, and octyl) were prepared by the decarboxylation of N-alkyl-3,4:9,10-perylenetetracarboxylic monoanhydride monoimides (same alkyls) in potassium hydroxide solution.
The Characteristic Behavior of Recoil Tritium Atom in Solid Neopentane at 77 K. The Application of a Hot Zone Model
Authors: Aratono Yasuyuki , Tachikawa Enzo , Miyazaki Tetsuo , Sakurai Masayuki , Fueki Kenji 
Published: July 2006

Abstract
The behavior of recoil tririum atoms in solid neopentane containing a small amount of alkane has been studied at 77 K by means of ESR spectroscopy and radio-gas chromatography. Though it was reported that the H (or D) atoms produced in the radiolysis and photolysis of solid neopentane react selectively with the solute alkane, the T atoms neither diffuse into the matrix at 77 K nor react selectively with the solute alkane. Most of the recoil T atoms react in their own track. The results are explained by a hot-zone model. The radius and the duration time of the hot zone are estimated to be ≈60 Å and ≈10−10 s respectively.
A New Method for Conformational Analysis by Photoelectron Spectroscopy with Application to Alkyl-substituted Styrenes
Authors: Kobayashi Tsunetoshi , Arai Tatsuo , Sakuragi Hirochika , Tokumaru Katsumi , Utsunomiya Chikatoshi 
Published: July 2006

Abstract
A new method for molecular conformational analysis using photoelectron spectral data was developed and applied to alkyl-substituted styrenes as an example. The dihedral angle between the phenyl ring and the olefinic group planes, θ, in each molecule is evaluated by comparing the observed difference between the first and the third vertical ionization energies, ΔEiv1.3, with the empirically estimated ΔEiv1.3 vs. θ curve, the alkyl substituent effect being taken into account by the first order perturbation theory. The new method gives reasonable results consistent qualitatively with those given by other former methods.
Mechanism of the Current Doubling Effect. I. The ZnO Photoanode in Aqueous Solution of Sodium Formate
Authors: Fujishima Akira , Kato Tamihiko , Maekawa Etsuro , Honda Kenichi 
Published: July 2006

Abstract
Current doubling mechanism of the photoanodic reaction of sodium formate at the ZnO electrode is re-examined. Quantitative analysis of the reaction products revealed that ZnO electrode corroded during the current doubling reaction, which has not been previously reported. However, zinc ions were formed with about 50% of current efficiency. Carbon dioxide, instead of oxygen, was formed during the reaction. These experimental observations strongly suggested mechanism proposed by earlier workers were incorrect. A new mechanism is proposed.
The IR Spectra of CsxV2O5 (x=0–0.66)
Authors: Kera Yoshiya 
Published: July 2006

Abstract
The IR spectra of Cs–vanadates (C=[Cs]/[V]=0–0.332) were recorded in the 650–1200 cm−1 region. In the V2O5, which had cautiously been purified, the V=O stretching band was found at 1022 cm−1, and the V–O–V stretching band, at 815 cm−1. Upon the addition of Cs, sharp new bands began to appear at 965 cm−1 at C=0.0042 and also at 1000 cm−1 at C=0.0120, and a shift in the 815-cm−1 band was found. Finally, at C=0.332 the original 1022-cm−1 band was replaced by the 965 and 1000 cm−1 bands, the intensity ratio (I965⁄I1000) of which was 2.0. The X-ray diffraction pattern of the last sample was in agreement with that of CsV3O8. The IR and the X-ray results suggest that the CsV3O8 phase appears at around C=0.004. Based on the band shifts of 1022→965 and 1000 cm−1, the force constant and the bond strength of V=O in CsV3O8 were discussed. With respect to the band shift in the 815-cm−1 region with the increase in the Cs content, the corretion of Δ\ ildeν to C1⁄3 is shown in C&lt;0.020.
Preparation and Properties of Monoalkylnickel(II) Complexes NiR(NR1R2)L2 Having Imido, Imidazolato, or Methyl Phenylcarbamato-N Ligand
Authors: Yamamoto Takakazu , Kohara Teiji , Yamamoto Akio 
Published: July 2006

Abstract
Reactions of dialkylnickel(II) complexes NiR2L2 1 (R=CH3, C2H5; L=1/2 bpy(2,2′-bipyridine), 1/2 dpe (1,2-bis(diphenylphosphino)ethane), PEt3) with compounds having acidic N–H bonds (succinimide, phthalimide, diacetamide, pyromellitimide (1,2 : 4,5-benzenebis(dicarboximide)), imidazole) gave corresponding monoalkylnickel(II) complexes having Ni–N bond formulated as NiR(NR1R2)L2. A reaction of NiMe2(PEt3)2 with CH3OH and phenyl isocyanate gives NiMe(N(Ph)COOMe)(PEt3)2. The IR, NMR, and visible spectroscopic studies of the complexes indicate that the electronegativity of Ni is enhanced by the replacement of one of the two R groups in 1 with the NR1R2 ligand. NMR spectra of complexes of a type NiMe(NR1R2)(PEt3)2 show that they have trans-configurations. Thermolyses of the monoalkylnickel(II) complexes start at temperatures higher by 80–100 °C than those of 1, liberating RH, R–R, and olefin R(–H). Exposure of monoethylnickel(II) complexes to air releases ethylene as the main gaseous product. Reactions of the complexes of a type NiR(phthalimido)L2 with R′X (R′=C6H5, C6H5CH2) and C6H5COCl produce N-alkyl- or N-arylphthalimide and ketone C6H5COR, respectively.
Catalysis by Mixed Oxide Perovskites. II. The Hydrogenolysis of C3–C5 Hydrocarbons on LaCoO3
Authors: Ichimura Kenji , Inoue Yasunobu , Yasumori Iwao 
Published: July 2006

Abstract
The catalytic hydrogenolysis of C3–C5 alkanes on LaCoO3 perovskite oxide was found to show a highly selective formation of methane in the temperature range of 350–620 K. The reaction order with respect to the hydrocarbon pressure was unity in every hydrogenolysis, whereas the hydrogen order increased from zero for propane to 1.0 for butane and isobutane and to 2.0 for pentane, isopentane, and neopentane. The activation energies of the reactions ranged from 120 for propane to 32 kJ mol−1 for butane. The reaction of propane or butane with D2 on LaCoO3 provided large fractions of methane [D3] and [D4], but a negligible amount of deuterium-exchanged alkanes. An equilibrium among the gaseous H2, HD, and D2 was reached. These hydrogenolyses are described by a mechanism involving the almost concurrent repture of all the carbon-carbon bonds in the alkanes by the attack of adsorbed hydrogen atoms, and were proposed to be catalyzed by a synergetic effect; the CO3+ ion is effective in breaking the C–C bond, whereas the La3+ and O2− ions serve to supply hydrogen atoms to the decomposed species. The reaction of propene or butenes with hydrogen produced the corresponding alkanes and methane. The kinetic analyses showed that the fractions of methane produced consecutively via the alkanes amounted to 16% for propene and to more than 93% for butenes. The observed pressure dependence and deuterium distributions in the alkene hydrogenation were interpreted in terms of the associative mechanism. The correlation between the structures of the reactant molecules and of the active sites present on LaCoO3 was briefly discussed.
The Structure of Liquid Water by Neutron Scattering
Authors: Ohtomo Norio , Tokiwano Kazuo , Arakawa Kiyoshi 
Published: July 2006

Abstract
A comprehensive analysis of the structure of liquid water was performed by combining neutron and X-ray diffraction data. A formula expressing the structure factor of fluids composed of small molecular clusters was obtained and applied to the analysis. In the interpretation of the diffraction data, the tetrahedral pentamer model as an aggregate of the regular tetrahedral pen tamers is considered to be the best structure model of liquid water from the excellent agreement between calculated structure factors and experimental data. Some critical discussions about other structure models were made.
Optical Resolution of Heterohelicenes by High Performance Liquid Chromatography
Authors: Nakagawa Hiroko , Ogashiwa Susumu , Tanaka Hisao , Yamada Koh-ichi , Kawazura Hiroshi 
Published: July 2006

Abstract
Heterohelicenes up to 15 rings were resolved by high performance liquid chromatography (HPLC) on silica gel covalently linked with a chiral charge transfer complexing agent 2-(2,4,5,7-tetranitro-9-fluorenylideneaminooxy)propionic acid(TAPA). The efficiency of resolution was discussed in terms of the helical structure of heterohelicenes.
ESR Spectra of Six-coordinate Cobalt(III) Tetraphenylporphyrin Cation Radicals Generated by Electrochemical Oxidation
Authors: Ohya-Nishiguchi Hiroaki , Khono Masahiro , Yamamoto Kiyoko 
Published: July 2006

Abstract
The ESR spectra of the paramagnetic species generated electrochemically from α,β,γ,δ-tetraphenylporphinatocobalt(II), [CoII(tpp)], have been observed under the conditions of low-temperature, in chlorinated or nonchlorinated solvents, and in the presence of various supporting electrolytes. From the ESR parameters obtained, three different paramagnetic species, [CoIII(tpp)]2+(X−)2, [CoIII(tpp)]2+(Y−)2, and [CoIII(tpp)]2+(X−)(Y−), have been confirmed. The ESR spectrum of thermally and optically accessible paramagnetic species in the solution of chlorotetraphenylporphinatocobalt(III) has been reproduced by the pertinent combination of solvent and supporting electrolyte, and well interpreted by assuming the formation of [CoIII(tpp)]2+(Cl−)2. Arguing from a correlation between the hfcc of cobalt and nitrogen nuclei in this species, a spin-polarization mechanism is proposed to interpret the cobalt hfcc.
Chloride-35 NMR Studies of the Ion Pairing of the Chloride Ion in Water and Aqueous Acetone
Authors: Yudasaka Masako , Sugawara Tadashi , Iwamura Hiizu , Fujiyama Tsunetake 
Published: July 2006

Abstract
The chloride-water mixture and the chloride-water-acetone mixtures were studied by measuring the 35Cl NMR spectra. From the line-width analyses, it has been concluded that the line-widths of the chloride solutions are affected only by the nearest neighbours of the chloride ions, which makes it possible to study the interaction between the chloride ion and the solvent molecules microscopically. The problem concerning the ion pair formation in solutions was discussed. It has been shown that the observation of the concentration dependence of line-widths can be very powerful method for the detection of contact ion pairs formed in the solutions.
Paramagnetic Cobalt(III) Complexes with Organic Ligands. VI. An X-Ray Photoelectron Spectroscopic Study
Authors: Yamamoto Yoshihisa , Mori Masayasu , Konno Hidetaka 
Published: July 2006

Abstract
Paramagnetic tetraammine-5-nitrosalicylato cobalt complex, paramagnetic μ-hyperoxo-dicobalt complexes and related diamagnetic compounds have been studied by X-ray photoelectron spectroscopy. In all these compounds, the binding energies of Co 2p electrons and their spin-orbit separation were those of usual Co(III) complexes. In the spectrum of paramagnetic tetraammine-5-nitrosalicylatocobalt salt, satellites appeared near the Co 2p peaks showing certain spin density at the cobalt atoms. At the same time, the C ls spectrum showed that considerable portion of carbon atoms has high binding energy suggesting delocalization of electron hole over the organic ligand. The O ls peaks in μ-hyperoxo complexes were ca. 0.6 eV higher than those in μ-peroxo complexes. Deconvolution of the O ls peak in the μ-OOH complex gave OH, =O–, and H2O peaks at the 1:1:1 ratio, supporting the μ-OOH formulation.
The Gibbs Energies, Enthalpies, and Entropies of the Dilution of Aqueous Sodium Chondroitin-4-sulfate and -6-sulfate
Authors: Yonese Masakatsu , Tsuge Hideya , Kishimoto Hiroshi 
Published: July 2006

Abstract
The osmotic coefficients of a solvent, φ, in aqueous solutions of sodium chondroitin-4-sulfate (NaChS-A) with a relatively low molecular weight and -6-sulfate (NaChS-C) with various molecular weight were measured by means of vapor-pressure osmometry. The molar Gibbs energes of dilution, ΔdilG were determined from the thermodynamic analysis of the φ values. The molar entropies of dilution, ΔdilS were calculated through the substitution of the molar dilution enthalpies, ΔdilH which had been measured previously, into ΔdilG. These thermodynamic quantities of dilution were discussed by taking Manning’s limiting law into consideration. The concentration and temperature dependencies of the observed ΔdilH agreed well quantitatively with those of the electrostatic ΔdilH calculated by Manning’s limiting law, when the distance between the neighboring charges of the polyion, b, was assumed to be 4.8 Å, whereas the observed ΔdilG and ΔdilS values did not agree quantitatively with the theoretical ones based on electrostatic interactions. From a comparison of the experimental ΔdilS values with the theoretical ones, the non-electrostatic dilution entropy was evaluated and discussed.
Preparation and Properties of Monoalkylnickel(II) Complexes Having a Phenoxo, Benzenethiolato, Oximato, β-Diketonato, or Halo Ligand
Authors: Yamamoto Takakazu , Kohara Teiji , Yamamoto Akio 
Published: July 2006

Abstract
Thirteen complexes of a type NiR(Y)Ln (R=CH3 (Me), C2H5 (Et); Y=OC6H5, p-cyanophenoxo, 8-phenylphenoxo, 8-quinolinolato, OCOEt, OCOPh, acetophenone oximato, acetylacetonato, benzoylacetonato, Cl; L=trie thy lphosphine (PEt3), 2,2′-bipyridine (bpy)) have been prepared by reactions of dialkylnickel(II) complexes NiR2L2 (1) with the corresponding active hydrogen compounds HY. Reactions of 1 with R′COY (Y=OC6H5, OCOC6H5, Cl) also afford the NiR(Y)Ln type complexes with formation of unsymmetrical ketones RCOR′. Reactions of 1 with alcohols lead to dehydrogenation of alcohols to afford aldehydes or ketones. The NiR(Y)Ln type complexes have been characterized by elemental analysis and spectroscopies (IR, NMR, visible). NMR spectra of trans-NiMe(OCOPh)(PEt3)2, NiMe(acetophenone oximato)(PEt3) (11), NiMe(benzoylacetonato) (PEt3) show temperature dependence, indicating occurrence of rapid dynamic reactions on NMR time scale in these complexes. The acetophenone oximato ligand in 11 is proposed to serve as an oxa-, aza-π-allylic ligand on the bases of IR and NMR spectroscopies. NiEt(OCOC2H5)(bpy) (8), NiEt(OCOC6H5)(bpy), and NiEt(Cl)(bpy) (14) undergo disproportionation reaction to give NiEt2(bpy) and NiY2(bpy) type complexes. Diethyl ketone is also produced during the disproportionation of 8. Reactions of 14 with olefins having electron-withdrawing substituents afford NiCl2(bpy) and Ni(olefin)2(bpy).
The Polarographic Behavior of Bis(acetylacetonato)nickel(II) and Bis(hexafluoroacetylacetonato)nickel(II) in Dimethyl Sulfoxide
Authors: Kudo Setsuko , Iwase Akio , Tanaka Nobuyuki 
Published: July 2006

Abstract
The d.c. polarographic reduction of Ni(acac)2 and Ni(hfac)2 was studied in detail in dimethyl sulfoxide. Two kinds of tetraalkylammonium perchlorates and sodium perchlorate were used as supporting electrolytes. Ni(acac)2 gave three waves in all the supporting electrolytes, while Ni(hfac)2 gave two waves in the presence of tetraalkylammonium perchlorate. These waves were explained on the basis of the polarographic properties, molecular weights, and conductivities. The electrode reaction mechanism of Ni(acac)2 can be expressed by:
(Remark: Graphics omitted.)
where the second wave includes a kinetic current. The first wave of Ni(hfac)2 is due to the reduction of Ni(hfac)+ and Ni(hfac)2 themselves; the second wave corresponds to that of free hexafluoroacetylacetonate.
Applications of Homogeneous Water-gas Shift Reaction. III. A Further Study of the Hydrocarbonylation. A Highly Selective Formation of Diethyl Ketone from Ethene, CO, and H2O
Authors: Murata Kazuhisa , Matsuda Akio 
Published: July 2006

Abstract
The hydrocarbonylation of ethene with CO and H2O produces diethyl ketone with a high selectivity of 99±1%(propanal 1±1%); a Co2(CO)8–phosphine system is used as an efficient catalyst, which is also active for the homogeneous water-gas shift reaction. The effects of the reaction parameters(CO pressure, temperature, and ethene and H2O concentrations) on the selectivity and activity are examined for the Co2(CO)8–1,2-bis(diphenylphosphino)ethane (diphos) system; the selectivity to yield the ketone is fairly high under the variety of conditions studied here. Evidence suggests that the active species which catalyze the water-gas shift reaction participate in the hydrocarbonylation of ethene.
Stereospecific and Stereoselective Reactions. V. Alkylation of Active Methylene Compounds by the Use of Alcohols, Diethyl Azodicarboxylate, and Triphenylphosphine
Authors: Kurihara Toshio , Sugizaki Masaru , Kime Itaru , Wada Makoto , Mitsunobu Oyo 
Published: July 2006

Abstract
The reagent formed by the reaction of diethyl azodicarboxylate (1) and triphenylphosphine (2) reacted with alcohols and ethyl cyanoacetate (6) to give alkylated products in 30–80% yields. When ethyl acetoacetate, 1,3-cyclopentanedione, or 1,3-cyclohexanedione was used in place of 6, the corresponding O-alkylated products were obtained. The reaction of either (S)-(−)-ethyl lactate or (S)-(−)-ethyl 2-hydroxy-3-phenylpropionate with 1, 2, and 6, followed by hydrolysis resulted in the formation of (S)-(−)-methylsuccinic acid or (S)-(−)-benzylsuccinic acid. The results indicate that nearly complete inversion of the configuration takes place in the alkylation step.
Asymmetric Reactions. X. Asymmetric Hydrogenation Catalyzed by Bis(dimethylglyoximato)cobalt(II)–Chiral Cocatalyst (Amino Alcohol) System
Authors: Ohgo Yoshiaki , Takeuchi Seiji , Natori Yukikazu , Yoshimura Juji 
Published: July 2006

Abstract
The catalytic asymmetric hydrogenations of α-diketones, α-keto carboxylates, α-(acylamino)acrylates, α-phenylacrylophenone, and α-phenylacrylate were examined with bis(dimethylglyoximato)cobalt(II)–chiral cocatalyst (amino alcohol) and with simple achiral base coordinated bis(dimethylglyoximato)cobalt(II)–chiral cocatalyst (amino alcohol) systems. These gave corresponding optically active reduction products, and in some cases, optically active reductive dimerization products. High degrees of enantioselectivities (≈78%) are achieved in the hydrogenation of α-diketones. Evidence for non-binding of chiral base to cobalt complexes was presented in the case of latter system, i.e., it was shown that the catalytic site and the enantioselectivity-determining site are separated in this system, as in enzymes. The importance of protonated chiral bases for enantioselection was also shown. Based on these results and the stereochemical correlations between structures of the chiral bases and those of the products, a mechanism for this asymmetric hydrogenation was proposed.