bluuebunny/crossref_metadata_2025_split huggingface dataset:
Generation and Reaction of (N-Aryltrifluoroacetimidoyl)zinc Halide
Authors: Tamura Kenji , Yan Fengyang , Sakai Takashi , Uneyama Kenji 
Published: July 2006

Abstract
(N-Aryltrifluoroacetimidoyl)zinc halides were easily generated at room temperature by the oxidative addition of imidoyl halides to activated zinc powder. [N-(2,6-Dichlorophenyl)- and N-(2,6-dimethylphenyl)trifluoroacetimidoyl]zinc halides react with aldehydes to give the corresponding alcohols smoothly in good to excellent yields. These adducts could be readily transformed to the α-amino ketones.
A Convenient Method for Introducing Oxo Group into the β-Position of Cyclic Amines and Its Application to Synthesis of δ-Aminolevulinic Acid
Authors: Matsumura Yoshihiro , Takeshima Yo-ichiro , Okita Hideki 
Published: July 2006

Abstract
Oxo group could be introduced into the β-position of N-methoxycarbonylated cyclic amines by utilizing electrochemical oxidation and/or m-chloroperbenzoic acid oxidation, and this method was applied to the preparation of δ-aminolevulinic acid, an intermediate of chlorophyll biosynthesis.
The Reaction of N-Cyanocarbonimidate and Related Compounds with Hydroxylamine
Authors: Suyama Takayuki , Ozawa Nobuyuki , Suzuki Noriyuki 
Published: July 2006

Abstract
O-ethyl S-methyl N-cyanocarbonimidothioate reacted with hydroxylamine to give 5-amino-3-ethoxy-1,2,4-oxadiazole, whereas diethyl N-cyanocarbonimidate reacted to give 3-amino-5-ethoxy-1,2,4-oxadiazole. The reaction of ethyl N-cyanocarbamate or S-methyl N-cyanothiocarbamate with hydroxylamine afforded 3-amino-1,2,4-oxadiazol-5(4H)-one.
Calixarene-Catalyzed Permanganate Oxidation of Organic Compounds
Authors: Nomura Eisaku , Taniguchi Hisaji , Otsuji Yoshio 
Published: July 2006

Abstract
The calix[6]arene 1 bearing six trioxadecyl groups on the phenolic oxygens served as an effective catalyst for the oxidation of alkenes, alkynes, and alcohols with KMnO4 in CH2Cl2. The reaction of alkenes, alkynes, and primary alcohols gave carboxylic acids in high yields, but that of secondary alcohols gave ketones in high or moderate yields.
Characteristics of Monolayers of Ferrocene Derivatives and Estimation of Electrical Double Layers Formed in Langmuir Films
Authors: Kondo Toshihiro , Ahuja Ramesh C , Möbius Dietmar , Fujihira Masamichi 
Published: July 2006

Abstract
In order to estimate the potential difference of the electrical double layer formed in heterogeneous Sensitizer (S)/Electron Donor (D) Langmuir–Blodgett (LB) films, the surface potentials of the constituent monolayers were measured simultaneously with the π–A isotherms. The S monolayer was a mixed [Ru(bpy)3]2+ complex monolayer with a long alkyl fatty acid, while the D monolayer was one of three kinds of ferrocene monolayers with different signs of the hydrophilic head groups and with the same redox potential. The formation of the potential difference between the charged head group of the amphiphile and its counterion at the water-air interface was confirmed; those values were consistent with the electrical double-layer effect on the luminescent lifetime of [Ru(bpy)3]2+ in the S monolayer in contact with the D monolayer.
Fogwater Chemistry at a Mountainside in Japan
Authors: Hosono Tetsuya , Okochi Hiroshi , Igawa Manabu 
Published: July 2006

Abstract
Fogwater had been observed for 4.5 years from July 1988 to December 1992 at the midslope of Mt. Oyama at the southwest of the Kanto plains. Rainwater, aerosol, and gases had been also collected and analyzed at the fog sampling station to investigate the characteristics and acidification mechanism of fogwater. The pH of fogwater ranged from 2.61 to 7.00 and the fog with very low pH values and high ion and aldehyde concentrations were frequently observed in spring and summer. The fogwater at the site was acidified primarily by nitric acid gas absorbed in fogwater and the acid fraction of most of the fogwater ranged from 0.3 to 0.01. The acidity of fogwater is controlled by the amount of the acidic pollutants in the atmosphere, the concentrations of the neutralizing components for the acidic fogwater, primarily NH3 gas concentration, the liquid water content in air, and the distance between the sampling station and the lowest altitude of the fog in upslope fog.
Crystal Structure of Barium Tetrahydroxo Borate (Ba[B(OH)4]2)
Authors: Watanabe Koichi , Sato Shoichi 
Published: July 2006

Abstract
The crystal structure as well as the chemical and physical properties of a new compound, barium tetrahydroxoborate (Ba[B(OH)4]2), are described. The compound is prepared by the chemical reaction of BaCl2 + 2NaBO2 + 4H2O = Ba[B(OH)4]2 + 2NaCl in an aqueous solution. The crystal is monoclinic, space group P21/n with cell constants a = 8.332(2), b = 16.522(3), c = 10.216(3) Å, β = 106.63(2)°, V = 1347.51(6) Å3, Z = 8, Dm = 2.90(1), Dc = 2.85(4) g cm-3. Melting point=ca. 1075 °C; Transition point (γ- to β-form) = ca. 532 °C. Refraction indexes: α = 1.567(6), β = 1.547(6), and γ = 1.517(8).
Equilibrium and Kinetic Studies on the Formation of Triphenylmethanols from Triphenylmethane Dyes
Authors: Hagiwara Takuyuki , Motomizu Shoji 
Published: July 2006

Abstract
For five kinds of triphenylmethane dyes, the rate constants of hydration and dehydration reactions, and equilibrium constants in an aqueous solution were measured by a stopped-flow method. An increase in the number of dialkylamino groups caused a decrease in the rates and the equilibrium constants of the hydration, and the more the electron-donating effect of the dialkylamino groups, the slower the hydration rate became. The more protonated quinonoids were easily converted to the corresponding alcohols. On the basis of the equilibrium constants, Malachite Green was ascertained to be the best reagent of the five dyes for ion association with heteropolyacids in an aqueous medium.
Toluidine Blue Selective Plasticized Poly(vinyl chloride) Membrane Electrode for Colloidal Titration
Authors: Hattori Toshiaki , Kawanishi Teruhiko , Kato Masanao 
Published: July 2006

Abstract
A plasticized poly(vinyl chloride) membrane electrode was applicable to colloidal titration without selective substances. The change of potential in the end-point, however, was too small to measure accurately. We prepared a new type of electrode with toluidine blue as an indicator. It was found that the electrode was quite useful to the colloidal titration. At the end-point a large change of potential was observed, and a small amount of polyelectrolyte anion could be titrated directly. Potassium poly(vinyl sulfates) was titrated with errors not more than 0.7% of r.s.d. in the amount of several micro chemical equivalents. This method was used to measure some poly(isoplene sulfonates) used as a dispersant polymer and its results agreed with that of acid-base titration.
Solvent Extraction of Several Divalent Metal Ions with Benzoyltrifluoroacetone and 2-Thenoyltrifluoroacetone into Chloroform in the Presence of Tetrabutylammonium Ions
Authors: Sekine Tatsuya , Nguyen Thi Kim Dung , Noro Junji 
Published: July 2006

Abstract
The solvent extractions of manganese(II), iron(II), cobalt(II), nickel(II), copper(II), zinc(II), and cadmium(II) (M2+) in 0.1 mol dm−3 sodium nitrate solutions with benzoyltrifluoroacetone and 2-thenoyltrifluoroacetone (HA) into chloroform were studied in the absence and presence of tetrabutylammonium ions (tba+). The addition of tba+ enhanced the extraction, except that of copper(II). This enhancement could be explained in terms of the extraction of the ternary complex, MA3−tba+, in addition to the neutral complex, MA2. The data were treated on the basis of the formation equilibrium of the ternary complex from the neutral complex, MA2, with the extracted ion-pairs of the reagents, A−tba+, in the organic phase. It was concluded that the association constants of MnA2, FeA2, CoA2, NiA2, and CdA2 with the ion-pair, A−tba+, are not very much different from each other. However, that of ZnA2 is lower than those of the five divalent metal complexes. This trend is similar to that found among the adduct metal complexes of β-diketonates with trioctylphosphine oxide (TOPO) in synergistic extraction systems.
Carboxylation of Active Methylene Compounds Using Anilide, Potassium Carbonate, and Carbon Dioxide
Authors: Chiba Koji , Tagaya Hideyuki , Karasu Masa , Ishizuka Masahiko , Sugo Toshiyuki 
Published: July 2006

Abstract
Active methylene compounds were effectively carboxylated with carbon dioxide in the presence of anilide (acetanilide or formanilide) and potassium carbonate at 20—40 °C for 0.5—10 h. In the carboxylation of fluorene, a high yield (48%) was obtained at 20 °C for 4 h. The yield of carboxylic acid using 2,6-dimethylacetanilide was 8.9%, and smaller than 26.6% when using acetanilide at 20 °C for 2 h, indicating the interference of a methyl group for the carboxylation.
Synthesis and Solid-State Polymerization of ω-(1,3-Butadiynyl) Substituted 1-Alkanol and Alkanoic Acid
Authors: Okada Shuji , Matsuda Hiro , Otsuka Masaaki , Kikuchi Naoto , Hayamizu Kikuko , Nakanishi Hachiro , Kato Masao 
Published: July 2006

Abstract
ω-(1,3-Butadiynyl) substituted 1-alkanol and alkanoic acid were synthesized and their polymerization behavior in crystals and in Langmuir–Blodgett (LB) films were investigated. Polymerization, using UV or γ-ray irradiation or thermal treatment, resulted in red- or golden-colored polymers. Since the absorption edge in the visible spectra of these polymers appeared at shorter wavelengths than those of the well known blue-colored polydiacetylenes, π-conjugation is considered to be deteriorated to some extent. IR, X-ray diffraction, and solid-state 13C NMR measurements showed that the polymerization does not proceed in a single-crystal-to-single-crystal transition manner via regular 1,4-addition but with deterioration of the crystalline lattice.
Synthetic Study of Lipoteichoic Acid of Gram Positive Bacteria. II. Synthesis of the Proposed Fundamental Structure of Enterococcus hirae Lipoteichoic Acid
Authors: Fukase Koichi , Yoshimura Takuya , Kotani Shozo , Kusumoto Shoichi 
Published: July 2006

Abstract
The proposed fundamental structure of Enterococcus hirae lipoteichoic acid (LTA) was synthesized in order to elucidate the chemical structure responsible for the cytokine-inducing activity described for the natural LTA fraction of this bacteria. Synthesis was accomplished by coupling of the glycolipid part with the poly(glycerol phosphate) (PGP) part by using a phosphoramidite method. The glycolipid part was constructed by coupling of the phosphatidic acid moiety with a kojibiosyl diacylglycerol which had been prepared by stepwise glycosidation with glycosyl fluorides. α-Selective glucosidations were effected by virtue of the 2,2,2-trichloroethoxycarbonyl (Troc) group introduced at the 6-hydroxyl function. p-Nitrobenzyl (NPM) and p-pivaloylaminobenzyl (PAB) groups were successfully applied to temporary protection of hydroxyl functions.
Synthesis and Solid-State Polymerization of ω-(4-Aryl-1,3-butadiynyl) Substituted 1-Alkanol and Alkanoic Acid
Authors: Okada Shuji , Matsuda Hiro , Otsuka Masaaki , Nakanishi Hachiro , Kato Masao 
Published: July 2006

Abstract
The amphiphilic diacetylenes with directly-bound aromatic substituents, i. e. 27-aryl-24,26-heptacosadiyn-1-ols and -diynoic acids, were synthesized and the solid-state polymerization of these compounds upon γ-ray and UV irradiation was investigated. More than half of the compounds synthesized are polymerizable because the packing effect of the methylene chains makes the diacetylene moieties align into polymerizable stack. It is found that the bulkiness of hydrophilic and hydrophobic ends was an impotant factor for the polymerizability of this series of compounds.
Bridge Contraction of [4]Ferrocenophanes by Wolff Rearrangement and Synthesis of [34](1,2,3,4)Ferrocenophane via the Contraction Reaction
Authors: Hisatome Masao , Watanabe Jun , Yamashita Rin-ichi , Yoshida Shuichi , Yamakawa Koji 
Published: July 2006

Abstract
The bridge contraction of α-oxo[4]ferrocenophane via a Wolff rearrangement was examined; β-formylation with ethyl formate, diazotization with tosyl azide and then irradiation with a mercury lamp in ethanol gave α-ethoxycarbonyl[3]ferrocenophane. A sequence of the reactions was applied to di- and tribridged α-oxo[4]ferrocenophanes to afford the corresponding [3]ferrocenophanes. The same reaction of α-oxo[4][33](1,2,3,4)ferroceneophane yielded α-oxo[3][33](1,2,3,4)ferrocenophane (20), but no α-ethoxycarbonyl[3][33](1,2,3,4)ferrocenophane, which was an usual product in the Wolff rearrangement in ethanol. The production of an unexpected compound 20 is possibly brought about by the addition of dioxygen to an ketene intermediate in the rearrangement, followed by removal of carbon dioxide. Reduction of 20 has led to the first synthesis of 1, tetrabridged ferrocenophane with trimethylene chains in a C2v symmetric mode.
Silicon Effects. VI. β-Silicon Effect of Various Silyl Groups in Solvolysis for α-Alkylbenzyl and α-Silybenzyl Systems
Authors: Shimizu Nobujiro , Watanabe Sin-ichiro , Hayakawa Fumie , Yasuhara Sigefumi , Tsuno Yuho , Inazu Takahiko 
Published: July 2006

Abstract
The kinetic β-silicon effects of various silyl groups including Me3Si, Me3SiMe2Si, (C6H5)Me2Si, (i-PrO)Me2Si, and (CH3OCH2)Me2Si were measured in kc solvolysis of two different benzylic systems of the types, ArCH(OCOCF3)CH2R (3: Ar = phenyl or 3,5-dichlorophenyl, R = silyl group) and C6H5CH(Cl)SiMe2R (4: R = silyl group). The relative β-silyl accelerations were 1.0 : 5.57 : 0.309 for R = Me3Si; Me3SiMe2Si, and (C6H5)Me2Si, respectively, for the system 3, and 1.0 : 7.65 : 0.502 : 0.289 for R = Me3Si, Me3SiMe2Si, (i-PrO)Me2Si, and (CH3OCH2)Me2Si, respectively, for the system 4. The variation of the β-silicon effect with γ-substituents was interpreted as reflecting changes in hyperconjugating abilities of β-C–Si and β-Si–Si σ-bonds mainly due to the inductive effect of the γ-substituent groups.
Asymmetric Reduction of β-Keto Esters with an Enzyme from Bakers’ Yeast
Authors: Kawai Yasushi , Tsujimoto Munekazu , Kondo Shin-ichi , Takanobe Kousuke , Nakamura Kaoru , Ohno Atsuyoshi 
Published: July 2006

Abstract
Various β-keto esters have been reduced by one of β-keto ester reductases isolated from bakers’ yeast. The corresponding β-hydroxy esters have been obtained in excellent enantiomeric and diastereomeric excesses, respectively. It has also been elucidated that the reductase recognizes the stereochemistry not only at the β-carbon but also at the α-carbon affording one of the four possible diastereoisomers of α-substituted β-hydroxy esters predominantly. The stereoselectivity is excellent and chemical yields are moderate to good.
A Kinetic Analysis of Superoxide Adduct Formation in the Presence of Typical Scavengers
Authors: Mitsuta Keiichi , Hiramatsu Midori , Ohya-Nishiguchi Hiroaki , Kamada Hitoshi , Fujii Kanae 
Published: July 2006

Abstract
The superoxide dismutase (SOD) activity of Cu,Zn-, Mn-, and Fe-SODs, and the SOD-like activity of ferricytochrome c, nitro blue tetrazolium (NBT), epinephrine, pyrogallol, l-ascorbic acid, and hydroxylamine, were investigated by the method of kinetic competition against superoxide radicals (O2−•) using ESR spectroscopy with a nitrone spin-trap 5,5-dimethyl-1-pyrroline N-oxide (DMPO). These activities depended on the pH and/or kind of the O2−• generating system used. A comparison of the results obtained for two O2−• generating systems of KO2 and hypoxanthine–xanthine oxidase showed that the effective pH in the former system was 1 or more higher than that in the latter. A new competition kinetic theory which includes a parameter of the stoichiometric ratio has been developed. Consequently, the profile of the non-stoichiometric competition reaction between DMPO and scavengers for O2−• was theoretically clarified.
Hydrogenation of Carbon Dioxide over Cu–Zn–Cr Oxide Catalysts
Authors: Fujiwara Masahiro , Ando Hisanori , Tanaka Mutsuo , Souma Yoshie 
Published: July 2006

Abstract
The hydrogenation of carbon dioxide for methanol synthesis was studied over Cu–Zn–Cr oxide catalysts, which were prepared by using CrO3 as a source of chromium. From the results of improving this type of catalysts, a catalyst prepared by the addition of copper–zinc carbonate to an aqueous solution of CrO3 was confirmed to be the most effective in this study. The detailed reaction behaviors, such as the dependence on the pressure, temperature and space velocity, were studied using this catalyst.
Catalytic Reduction of Nitrogen Monoxide by Propene in the Presence of Oxygen over Cerium Ion-Exchanged Zeolites. I. General Characteristics of the Reaction and Effects of Alkaline Earth Metal Addition
Authors: Yokoyama Chikafumi , Misono Makoto 
Published: July 2006

Abstract
Catalytic reduction of dilute nitrogen monoxide by propene in the presence of excess oxygen was studied over various metal ion-exchanged zeolites. The presence of propene and oxygen was essential for the reaction. Ce–zeolites, particularly Ce–ZMS-5, showed a very high catalytic activity for the reduction of nitrogen monoxide. The high activity of Ce–ZSM-5 was attributed to its high selectivity (high efficiency of the use of propene for the reduction). The addition of alkaline earth metals to Ce–ZSM-5 enhanced the activity considerably and the Ce–ZSM-5 containing alkaline earth metals showed good performance even at a very high space velocity (GHSV = 105 h−1).
Synthesis of Heat-Resistant Polyester Containing Rigid Biphenyl Moiety by Palladium-Catalyzed Carbonylation-Polycondensation
Authors: Kubota Yoshihiro , Takeuchi Kazuhiko , Hanaoka Taka-aki , Sugi Yoshihiro 
Published: July 2006

Abstract
For the purpose of synthesizing heat-resistant polyesters, the one-step synthesis of a rigid biphenyl-containing polyester from dihalobiphenyl and diol by palladium-catalyzed carbonylation-polycondensation was examined. The reaction parameters, such as the base, solvent, palladium–phosphine catalyst and CO pressure in the reaction of 2,7-dibromo-9,10-dihydrophenanthrene and 4,4′-(1-methylethylidene)bisphenol (bisphenol A), were found to significantly affect the molecular weight of the resulting polyester. Under the optimum conditions, poly[oxy-1,4-phenylene(1-methylethylidene)-1,4-phenyleneoxycarbonyl(9,10-dihydro-2,7-phenanthrenediyl)carbonyl] (1) were obtained in 95% yield with high molecular weight (polystyrene equivalent Mw = 102600). By choosing the phosphine ligands and controlling the pressure of carbon monoxide, polymer 1 was obtained with a Mw of 10000—100000. The procedure was applied to various dihalobiphenyls and diols. Polycondensation with 1,10-decanediol gave poly[oxydecamethyleneoxycarbonyl(9,10-dihydro-2,7-phenanthrenediyl)carbonyl] (15) with a much lower molecular weight (Mw = 4900) than polyester 1. On the basis of a thermal analysis, a 5% weight-loss temperature (T5) and a 10% weight-loss temperature (T10) of 1 in air was 394 and 414 °C, respectively, whereas melting temperature (Tm), T5, and T10 of 15 were 148, 369, and 383 °C, respectively.
Pressure Effects on Equilibrium between Lactone and Zwitterion Forms of Rhodamine B in Primary Alcohols
Authors: Sueishi Yoshimi , Sugiyama Yukie , Yamamoto Shunzo , Nishimura Norio 
Published: July 2006

Abstract
The equilibrium between lactone and zwitterion forms of Rhodamine B was studied in primary alcohols and at high pressures. The effects of solvent polarity and pressure on the equilibrium constant were examined by using a Kirkwood-type equation.
A New Synthesis of 3-Isochromanone Derivatives Based on the Reaction of o-Acylbenzyllithiums with Ethyl Chloroformate
Authors: Kobayashi Kazuhiro , Mannami Tohru , Kawakita Masataka , Tokimatsu Junsuke , Konishi Hisatoshi 
Published: July 2006

Abstract
A new method for the preparation of 3-isochromanone derivatives is reported. The method consists of the ethoxycarbonylation of o-acylbenzyllithiums with ethyl chloroformate and the subsequent NaBH4 reduction of the resulting o-acylphenylacetic acid derivatives.
Indirect Electrochemical Radical Cyclization of Bromo Acetals by the Combined Use of Cobaloxime and Sacrificial Electrode
Authors: Inokuchi Tsutomu , Kawafuchi Hiroyuki , Aoki Kenji , Yoshida Akihito , Torii Sigeru 
Published: July 2006

Abstract
An improved procedure for the electrochemical radical cyclization of 2-bromoethyl 2-alkynyl ethers has been developed by the combined use of chloro(pyridine)cobaloxime(III) and a zinc plate as a sacrificial anode in an undivided cell. The reaction is feasible with 5 mol% of the cobalt catalyst and applicable to a variety of bromo acetals under neutral conditions.
Thermal Rate Constants for SiH4→← SiH3 + H and CH4→← CH3 + H by Canonical Variational Transition State Theory
Authors: Takahashi Junko , Momose Takamasa , Shida Tadamasa 
Published: July 2006

Abstract
The thermal rate constants for SiH4 SiH3 + H and CH4 CH3 + H are calculated by the Canonical Variational Transition State Theory (CVTST). The minimum energy path potential and the deformation path potential along the reaction coordinate are calculated by the MCSCF-CI and UHF methods, respectively. The transitional bending mode which connects the bending vibrations of the parent molecules with the translational and rotational motions of the products of the dissociation is treated in terms of a two-dimensional quantum hindered rotor. The saddle points and the CVTST rate constants are determined by the maximum free energy criterion. Comparative discussions are made for the two systems. The calculated association rate constants for the SiH4 system are 8.4 × 1010 l mol−1 s−1 at 300 K and 12.5 × 1010 l mol−1 s−1 at 2000 K, while those for the CH4 system are 12.5 × 1010 l mol−1 s−1 and 18.6 × 1010 l mol−1 s−1 at the two temperatures. At all the temperatures studied the rate constant of the former system is smaller by 30—35% than the latter. The dissociation rate constants are evaluated to be 7.2 × 105 s−1 at 2000 K and 1.2 × 109 s−1 at 3000 K for the SiH4 system, while the constant for the CH4 system at 2000 K is about one order of magnitude smaller. This difference diminishes at higher temperatures. The results are also compared with experimental and other theoretical studies.
Studies on Some Lanthanoid Complexes of Heterocyclic Ligands: Complexes of 2-Pyrazinecarboxamide with Hydrogen-Bonding
Authors: Rao Thatavarthi Ramalingeswar , Kumar Poluri Anjana 
Published: July 2006

Abstract
Lanthanoid complexes of 2-pyrazinecarboxamide (PYZA) of the composition, [LnCl3(pyza)3] (Ln = La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, and Y), were synthesized and the structures of the isolated complexes studied by elemental analyses, molar conductance, magnetic susceptibility, electronic, FT-IR and multinuclear NMR spectral techniques. Presence of intra- and intermolecular hydrogen bonding in the non-complexed (free state) PYZA and intramolecular hydrogen bonding in the complexed ligand (Ln(III) complex) was indicated by the FT-IR spectra (solution and solid states). Non-coordination through the &gt;C=O and –NH2 groups in the Ln(III) complexes was implied by the FT-IR (solution state) and 13C NMR spectra. The 139La NMR spectrum implied a predominantly ionic bond and low symmetry in the complexes. The hypersensitive band profile of the Nd(III) complex remained uneffected with respect to pH and temperature variations.