bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gas Sensitivities of Polypyrrole Films to Electron Acceptor Cases
Authors: Hanawa Tetsuro , Yoneyama Hiroshi 
Published: July 2006

Abstract
Electropolymerized polypyrrole films exhibited noticeable gas sensitivities to electron acceptor gases such as PCl3, SO2, and NO2 at room temperature only when they were reduced electrochemically, and the resistance decrease was larger with the gas of larger electron affinity. It was also found that the resistance decrease obeyed the Elovich equation in an early stage of the gas exposure.
Light-Induced Oxidative Deposition of Polypyrrole on the Back Surface in the Dark of n-Type Silicon Wafer Photocatalysts
Authors: Yoneyama Hiroshi , Shoji Yoshihiro , Suzuki Kei-ichi 
Published: July 2006

Abstract
A variety of surface conditions of n-type Si wafers were prepared by etching for different time damaged surfaces that were prepared by lapping with emery papers, and the effect of flaws in the wafer surfaces on photocatalytic deposition behaviors of polypyrrole and silver from acetonitrile containing pyrrole and AgClO4 was investigated. It was found that if the front surface of the wafer to be illuminated contained a fairly high amount of defects and the back surface in the dark was defect-free, oxidative polymerization of pyrrole occurred on the back surface in the dark with the simultaneous deposition of silver on the front surface as long as the diffusion length of positive holes is greater than the thickness of Si wafers.
Ionic Partial Molar Volumes of Alkali Halides in Methanol as Evaluated from the Sedimentation Potentials
Authors: Hirakawa Hiromitu , Nomura Hiroyasu , Kawaizumi Fumio 
Published: July 2006

Abstract
Sedimentation potential (SP) measurements were carried out for solutions of alkali halides dissolved in methanol. With the SP data thus obtained, the partial molar volumes V2∞ of alkali halide MX, V2∞ (MX), were divided into cationic V2∞ (M+) and anionic V2∞ (X−) parts. The ionic partial molar volumes evaluated showed a reasonable agreement with each other. These values of V2∞ (M+) and V2∞ (X−) are numerically compatible with those reported earlier by Kawaizumi and Zana using the ultrasonic vibration potential method and those given more recently by French and Criss based on the apportionment of the estimated V2∞ value for the large complex [Ph4PBPh4] (J. Solution Chem., 11, 625 (1982).) The magnitude of the concentration dependence of SP was evaluated theoretically by expressing the apparent molar volume, the transport number, and the density of a solution as functions of the solute concentration.
The Syntheses of Ortho-, Meta-, and Paracyclophane-Type Thiacrown Compounds and Their Characteristics as Extractive-Spectrophotometric Reagents for Class b Metals–Silver and Copper
Authors: Muroi Motoho , Kamiki Teruo , Sekido Eiichi 
Published: July 2006

Abstract
Ortho-, meta-, and paracyclophane-type thiacrown compounds bearing 4-(4-nitrophenylazo)phenol as a chromogenic group were synthesized, and their characteristics as extractive-spectrophotometric reagents for the class b metals, consisting of soft Lewis acids such as silver and copper(I), were examined. Silver and copper(I) were well extracted into chloroform with all of three reagents, though especially with the metacyclophane-type reagent. The absorption maxima of silver and copper(I) complexes with the orthocyclophane-type reagents are at the longest wavelengths among the three reagents. The orthocyclophane-type reagent is adequate for the extraction and spectrophotometric measurement of copper(I), and the metacyclophane-type reagent is suitable for that of silver. The extraction behavior of copper(II) with these three reagents has been studied in order to know if the hydroxyl group participates in the formation of the metal–thiacrown complexes.
Design of the Synthetic Route for Helical Peptides. Synthesis and Solubility of Model Peptides Having a Helical Structure
Authors: Narita Mitsuaki , Kojima Yoshihisa , Isokawa Shizuko 
Published: July 2006

Abstract
Fragment condensations between amino- and carboxyl-components of hydrophobic decapeptides, which have a β-sheet structure in the solid state and are insoluble in DMF, NMP, and DMSO, were examined in a mixture of CH2Cl2 and TFE (4/1, v/v) using various coupling reagents. By the use of DCC and HOBt as coupling reagents, the reaction proceeded smoothly in moderate yield to give eicosapeptides. These have a stable helical structure in the solid state and are easily soluble in a variety of organic solvents. The hydrophobic eicosapeptides obtained were subjected to a successive coupling reaction in CH2Cl2 alone to give helical tetracontapeptides in high yield, which also have high solubility in various organic solvents of low polarity. The solubility of hydrophobic helical peptides presents a solubility feature of helical peptides which are obtained as peptide intermediates in protein synthesis. The synthetic strategy for helical peptides and proteins is discussed in connection with the solubility prediction method.
Aldol Addition of Butyraldehyde over Solid Base Catalysts
Authors: Zhang Geng , Hattori Hideshi , Tanabe Kozo 
Published: July 2006

Abstract
Aldol addition of butyraldehyde was investigated on alkaline earth oxides, zirconium oxide, and lanthanum oxide to compare the active site and mechanism with those for aldol addition of acetone. It is found that the active site is the surface O2− and the rate-determining step is α-H abstraction.
Asymmetric Oxidation of Alkyl Aryl Selenides under Sharpless Oxidation Conditions
Authors: Shimizu Toshio , Kobayashi Michio , Kamigata Nobumasa 
Published: July 2006

Abstract
Optically active alkyl aryl selenoxides were synthesized by the asymmetric oxidation of corresponding selenides under Sharpless oxidation conditions. The absolute configurations of the optically active alkyl aryl selenoxides prepared were estimated by comparisons of their circular dichroism spectra with those of the optically active sulfoxides.
1H NMR Conformational Study of Viologen-Linked Porphyrins
Authors: Yamamoto Yasuhiko , Noda Sumio , Nanai Norishige , Okura Ichiro , Inoue Yoshio 
Published: July 2006

Abstract
Novel porphyrins to which the viologen is linked (m-PCnV) were synthesized. The linkage methylene chain between the porphyrin and the bipyridine moieties was systematically changed from (CH2)3 to (CH2)6. The molecular structure of m-PCnV was characterized by 1H NMR in some detail. The orientation of the viologen with respect to the porphyrin plane in m-PCnV was semiquantitatively estimated from the porphyrin ring current induced chemical shift changes on the resonances from the viologen moiety. The NMR conformational analyses on m-PCnV in dimethyl sulfoxide and acetonitrile clearly revealed the effect of the solvent on its molecular structure.
Cyclohepta[b][1,4]benzoxazines 3. The Reaction of 6-Bromocyclohepta[b][1,4]benzoxazine with o-Aminophenol
Authors: Nozoe Tetsuo , Okai Harue , Wakabayashi Hidetsugu , Ishikawa Sumio 
Published: July 2006

Abstract
The reaction of 6-bromocyclohepta[b][1,4]benzoxazine (19) and o-aminophenol (3) was studied and compared with that of 3-bromo-2-methoxytropone (2) with 3. 14H-[1,4]Benzoxazino[3′,2′:3,4]cyclohepta[1,2-b][1,4]benzoxazine, 10-(o-hydroxyanilino)cyclohepta[b][1,4]benzoxazine (D), 1- and 4-formylphenoxazines and their Schiff bases (C and X) were obtained in very good yields by modifying the conditions of the reaction of 19 with 3. Structures of D, C, and their isomers were determined and the possible reaction pathways for the formation of various products are discussed.
Lanthanoid(III) Trichloride–Tin(II) Chloride Mediated Cydoaddition Reaction of α,α′-Dibromo Ketones with 1,3-Dienes or Enamines
Authors: Fukuzawa Shin-ichi , Fukushima Masakazu , Fujinami Tatsuo , Sakai Shizuyoshi 
Published: July 2006

Abstract
The reaction of α,α′-dibromo ketones with 1,3-dienes in the presence of CeCl3–SnCl2 in tetrahydrofuran is found to give the corresponding [3+4] cycloadduct in fair to good yields under mild conditions. Furan and cyclopentadiene serve as highly efficient receptors of the oxyallyl intermediate to give bicyclic cycloadducts. The reaction of 2,4-dibromo-3-pentanone with isoprene gives both [3+4] and [3+2] cycloadducts. [3+2] Cycloaddition proceeds similarly with enamines to afford 2-cyclopenten-1-ones after treatment with 3% ethanolic NaOH solution.
The Molecular Structure of a Schiff Base Complex, [N,N′-Ethylenebis(1-phenyl-2-imino-1-butanonato)](acetonitrile)manganese(III) Perchlorate
Authors: Xu Duanjun , Chen Banglin , Chen Ke , Chen Chaorong , Miki Kunio , Kasai Nobutami 
Published: July 2006

Abstract
The molecular structure of a novel Schiff base complex, [N,N′-ethylenebis(1-phenyl-2-imino-1-butanonato)](acetonitrile)manganese(III) perchlorate has been determined by X-ray diffraction method. The molecule has an elongated octahedral geometry around the metal atom.
Shift References in High-Resolution Solid-State NMR
Authors: Hayashi Shigenobu , Hayamizu Kikuko 
Published: July 2006

Abstract
The high-resolution solid-state 13C, 29Si, 31P, 23Na, 27Al, and 11B NMR spectra of several compounds have been measured using magic-angle sample spinning. Their isotropic chemical-shift values have been determined accurately to use as shift references in solid-state NMR; this makes comparison between literature shift data possible.
Mass Spectrum and Thermal Behavior in Solid State of N,N-Di(1-hydroxyalkyl)-2-imidazolidinone
Authors: Shimasaki Choichiro , Nakajima Kyoko , Sugimori Yuka , Tsukurimichi Eiichi , Yoshimura Toshiaki 
Published: July 2006

Abstract
1,3-Bis(1-hydroxyalkyl)-2-imidazolidinones (1) were prepared by the reaction of imidazolidinone with propyl-, butyl-, isobutylaldehyde. They were unstable and moisture-sensitive substances, except for 1,3-bis(1-hydroxybutyl)-2-imidazolidinone (1c). In the decomposition by the electron impact of 1 and the dimer of 1c, the molecular ion peak of 1 was not detected. The fragmentation of the imidazolidinone ring was considered to take place after a successive cleavage of the two side chains of 1. The pyrolysis reaction of 1 was found to be a thermal decomposition via a molten state after a condensation reaction. The order of the pyrolysis was calculated on the basis of DSC curves. The condensation stage for 1c apparently obeyed 1/2-order kinetics. From the dependence of the velocity on the temperature in DTA and the thermogravimetric analysis, the activation energy of decomposition was calculated; the value for the former was 67 and the latter 73 kJ mol−1. The mechanism of pyrolysis was supported by the results of the IR spectrum and chemical analysis.
Environmental Effects on the Absorption and Fluorescence Spectral Characteristics of Benzimidazole-2-carboxylic Acid and Its Ester
Authors: K. Sinha Hemant , K. Dogra Sneh 
Published: July 2006

Abstract
The absorption and fluorescence spectra of benzimidazole-2-carboxylic acid (BIA) and 5-chlorobenzimidazole-2-carboxylic acid (CBIA) have clearly indicated that benzimidazole (BI) ring and –COOH group are coplanar to each other and are held together in a rigid frame by intramolecular hydrogen-bonding. Dual fluorescence in observed in polar and hydrogen bonding solvents. The short wavelength fluorescence band is assigned to a structure where the –COOH group is perpendicular to the BI moiety and the long wavelength fluorescence band to the planar configuration. This is further manifested from the spectral characteristics of the ester of 5-chlorobenzimidazole-2-carboxylic acid (CBIM). Various prototropic reactions taking place in S0 and S1 states for all the three molecules are studied in the H0/pH/H− range of −10 to 16. All the dissociation constants are determined, both in the S0 and S1 states and are discussed.
The Synthesis of C-Nucleoside Precursors. II. Synthesis and Conformational Analysis of 3-(Pentahydroxypentyl)-6-phenyl-1,2,4-triazolo[3,4-a]phthalazines
Authors: A. E. Shaban Mohammed , A. M. Taha Mamdouh 
Published: July 2006

Abstract
Reaction of 1-hydrazino-4-phenylphthalazine with aldohexoses (d-galactose, d-glucose, d-mannose, and d-talose) and 6-deoxyaldohexoses (l-fucose and l-rhamnose) gave the colored aldehydo-sugar (4-phenyl-1-phthalazinyl)hydrazones or the colorless 3-(pentahydroxypentyl)-6-phenyl-1,2,4-triazolo[3,4-a]phthalazines. The former can be cyclized to the latter by catalytic dehydrogenation. Structure elucidation of the prepared compounds was made on the basis of their various spectral properties. The C-nucleoside precursors were further characterized as their O-acetyl derivatives and the configurational–conformational correlation of these acetates was studied. Some of the prepared compounds were screened for insectidicidal, nematicidal, and herbicidal activities and found to be inactive. They showed, however, good corrosion inhibition of aluminium in acid solutions.
Hydrothermal Synthesis of Gallium Orthophosphate Crystals
Authors: Hirano Shin-ichi , Kim Pan-chae 
Published: July 2006

Abstract
Synthesis and crystal growth of GaPO4 have been carried out in order to elucidate the properties of gallium orthophosphate. Single crystals were hydrothermally grown in the low temperature range from 150 to 180 °C. Solubility of GaPO4 was measured under hydrothermal conditions, and the temperature coefficient of solubility was found to be negative in H3PO4 solution. Single crystals have morphologies bounded by the major rhombohedral (10\bar1 1) faces under lower temperature and pressure conditions. Polymorphs of GaPO4 exist corresponding to low quartz type, low and high cristobalite types.
Redox Behaviors of Glassy Carbon Electrodes Modified with [Fe4X4(YC6H4-p-t-C4H9)4]2− (X, Y=S and Se) in Water
Authors: Tanaka Koji , Nakamoto Masami , Taru Yoshihisa , Tanaka Toshio 
Published: July 2006

Abstract
Cyclic voltammograms of glassy carbon electrode modified with iron–sulfur and iron–selenium clusters (Bu4N)2[Fe4X4(YC6H4-p-t-C4H9)4] (X, Y=S, Se) show the stable (2−/3−) redox couple in water, and the peak potentials of those redox waves are shifted by the change of pH due to reversible protonations not only of the oxidized but also of the reduced clusters. The electron transfer between the cluster and the glassy carbon plate is also influenced by the protonation equilibrium. A retardation of the electron transfer caused by the protonation of the cluster may be associated with a reorganization energy required in the redox reaction of the protonated cluster.
Determination of Individual Partial Molar Volumes of Ions in Water from Measurements of Ultrasonic Vibration Potentials
Authors: Takenaka Nobuo , Arakawa Kiyoshi 
Published: July 2006

Abstract
A new apparatus for measurements of ionic vibration potentials generated by the propagation of ultrasonic waves through electrolyte solutions was constructed, and used for the determination of partial molar volumes of ions in aqueous solutions of uni-univalent electrolytes. The apparatus, based on the method of ultrasonic vibration potentials (Zana and Yeager), was improved in two points through the introduction of the Doppler effect: a small measuring cell (about 50 cm3) and very low noises (50 nV). Then, measurements of temperature variation of ultrasonic vibration potentials have become possible. Partial molar volumes of hydrogen, alkali metal, and halide ions in water were determined in the range of temperature, 15–45 °C.
Formation of Magnesium and Chloroaluminium Phthalocyanine Thin Films Exhibiting an Intense Near-Infrared Absorption by Electrolysis of Surfactants with Ferrocenyl Moiety
Authors: Saji Tetsuo 
Published: July 2006

Abstract
Magnesium or chloroaluminium phthalocyanine (1 and 2) was dispersed to the micellar solution formed by a non-ionic surfactant with ferrocenyl moiety (3). The thin films prepared by the controlled-potential electrolysis of the micellar solution exhibited an intense nearinfrared absorption.
Photoreactions of Polyhalobenzenes in Benzene. Formation of Terphenyls
Authors: Nakada Masahiro , Miura Chihiro , Nishiyama Hideaki , Higashi Futoshi , Mori Toru , Hirota Minoru , Ishii Tetsuo 
Published: July 2006

Abstract
Polychlorobenzenes, polybromobenzenes, and polychloropolybromobenzenes (C6H6−nXn) were photolyzed in benzene solutions; the products were analyzed by the GC/MS method. Both dehalogenation and phenylation were shown to take place competitively, producing (poly)halobenzenes bearing one less halogen atom (C6H7−nXn−1) and (poly)halobiphenyls (C6H6−nXn−1–C6H5) as the major products. Besides these products, terphenyl was produced by a consecutive phenylation of the halobiphenyl formed. Polychlorobenzenes were shown to form the corresponding terphenyls only when a pathway via 2-chlorobiphenyl is possible; however, polybromobenzenes can produce terphenyls through any of the isomeric bromobiphenyls intermediarily formed. Isomerization through m-migration of a chlorine atom was also shown to occur to a considerably lesser extent.
The Electronic Spectra of Jet-Cooled Tropolone. Vibrational Assignment for the \ ildeA1B2–\ ildeX1A1 Transition
Authors: Sekiya Hiroshi , Nagashima Yusuke , Nishimura Yukio 
Published: July 2006

Abstract
The laser fluorescence excitation spectrum and the single vibronic level fluorescence spectra from the \ ildeA1B2 state of tropolone have been measured in a supersonic free jet. Some vibronic bands observed in the region of 270–450 cm−1 from the 000 band have been assigned. A tunneling doublet separation for the ν′14 in-plane ring deformation mode has been measured to be 30 cm−1, which is significantly larger than 19 cm−1 for that for the zero-point level, suggesting that the average geometry of the ν′14 mode deviates significantly from that of the zero-point level.
Synthetic, Spectroscopic and X-Ray Crystallographic Studies of Bivalent Metal Complexes with Amino Acids Having a Thiazolidine Ring. III. The Properties of Bivalent Metal Complexes with Racemic 2-Thiazolidinecarboxylic Acid and the Structure of trans-Diaquabis(2-thiazolidinecarboxylato)zinc(II)
Authors: Nagase Makoto , Yukawa Yasuhiko , Inomata Yoshie , Takeuchi Toshio 
Published: July 2006

Abstract
Several complexes with the formula of ML2·2H2O (HL=racemic 2-thiazolidinecarboxylic acid, (Remark: Graphics omitted.)–COOH, M=Co, Ni, Zn), anhydrous CdL2 and CdCl2(HL) were synthesized and characterized by means of their infrared absorption and reflection spectra, magnetic susceptibility, thermal analyses, and powder X-ray patterns. In addition, the crystal structure of ZnL2·2H2O was also determined. Crystals of this complex are monoclinic, with the space group P21⁄n with a=7.224(1), b=18.246(4), c=5.306(1) Å, and β=104.57(1)° and Z=2. The structure was solved by the heavy atom technique and refined by a block-diagonal least-squares method to a final R value of 0.056 for 1774 unique reflections. The zinc environment consists of two carboxylic oxygen atoms and two thiazolidine nitrogen atoms from two centrosymmetrically related organic ligands in a square-planar arrangement. Two water molecules in the axial positions complete a tetragonal bipyramidal coordination around the metal atom. No sulfur atom is coordinated to the zinc atom. The infrared absorption spectra and the structure of this zinc(II) complex are discussed in comparison with those of zinc(II) complexes with (S)-4-thiazolidinecarboxylic acid and racemic 4-thiazolidinecarboxylic acid.
Formation of (η-Cyclopentadienyl)(1,2-ethylenedithiolato, 1,2-ethylenediselenolato, and 2-selenolatoethylenethiolato-S,Se)cobalt(III) Complexes in a One-Pot-Reaction of (η-Cyclopentadienyl)(1,5-cyclooctadiene or dicarbonyl)cobalt(I) with Alkyne and a Mixture of S8 and Se8
Authors: Kajitani Masatsugu , Ochiai Ryuji , Dohki Kakushi , Kobayashi Norikazu , Akiyama Takeo , Sugimori Akira 
Published: July 2006

Abstract
A one-pot-reaction of (η-cyclopentadienyl)(1,5-cyclooctadiene or dicarbonyl)cobalt(I) with alkyne (diphenylacetylene and phenylacetylene) and a mixture of S8 and Se8 gives (η-cyclopentadienyl)(2-selenolatoethylenethiolato-S,Se)cobalt(III) complex in addition to the corresponding dithiolato and diselenolato complexes. When phenylacetylene was used as an alkyne, a (2-phenyl-2-selenolatoethylenethiolato-S,Se)cobalt(III) complex was formed preferentially rather than the (1-phenyl-2-selenolatothiolato-S,Se)cobalt(III) complex. The separation of the diselenolato and selenolatothiolato complexes from the dithiolato complex was successfully done by utilizing the difference in how these complexes form adducts with tributylphosphine. The dithiolato complexes have more negative reversible half-wave potentials (for reduction) than the diselenolato complexes; the selenolatothiolato complexes have intermediate half-wave potentials.
Photochemical Reaction of Benzophenones with Allylic Silanes
Authors: Takuwa Akio , Fujii Naomi , Tagawa Hiroyuki , Iwamoto Hidetoshi 
Published: July 2006

Abstract
Photocycloaddition and hydrogen abstraction reactions between benzophenones and allylic silanes have been investigated. The high regioselective oxetane formations were explained in terms of an additional stability due to the σSi–C–pπ hyperconjugation of β-silyl radicals in diradical intermediates. Allyl radical substituted by a trimethylsilyl group, which was generated from a hydrogen abstraction reaction, recombined with benzophenone ketyl radical at the γ position. No electron transfer products were observed in the reactions.
Synthesis of Ceratiolin, a Constituent of Ceratiola ericoides
Authors: Obara Heitaro , Onodera Jun-ichi , Yusa Katsuhiro , Tsuchiya Mitsuhiro , Matsuba Shigeru 
Published: July 2006

Abstract
Ceratiolin, a constituent of Ceratiola ericoides was synthesized by the methylation of 2′,3′,4′,6′-tetrahydroxydihydrochalcone, prepared by the Hoesch reaction of 1,2,3,5-benzenetetrol with 3-phenylpropionitrile. Furthermore, it was proved that ceratiolin easily forms by the oxidation of 2′,4′,6′-trihydroxy-3′,5′-dimethyldihydrochalcone.
Photoinduced Intramolecular Cyclization Reaction of 3-Substituted 2-Alkenoyl-1,4-benzoquinones
Authors: Iwamoto Hidetoshi 
Published: July 2006

Abstract
Irradiation of 3-alkoxy-2-alkenoyl-1,4-benzoquinones in solution gave tricyclic compounds (5H-pyrano[4,3,2-de][1,3]benzodioxin derivatives) and 3-alkylthio-2-alkenoyl-1,4-benzoquinones gave similar products (5H-pyrano[4,3,2-de][3,1]benzoxathiin derivatives). Each reaction initiates via γ-hydrogen abstraction by photoexcited quinone to produce diradical intermediates which intramolecularly cyclize to give the products.
Preparation and Properties of Tetrathia[n](1,1′)ferrocenophanes with Pd(BF4)2. The Metal–Metal Interaction Controlled by the Size of the Thiamacrocycles
Authors: Sato Masaru , Akabori Sadatoshi 
Published: July 2006

Abstract
1,4,7,10-Tetrathia[10]-, 1,4,8,11-tetrathia[11]-, 1,5,8,12-tetrathia[12]-, and 1,5,9,13-tetrathia[13](1,1′)ferrocenophanes reacted with (CH3CN)4Pd(BF4)2 to give the corresponding 1/1 complexes in good yield. The 1H NMR spectra of the Pd(II) complexes were not rigid at room temperature, except for the complex of 1,4,7,10-tetrathia[10](1,1′)ferrocenophane. The 1H and 13C NMR spectra at low temperature showed that the Pd(II) complex of 1,5,9,13-tetrathia[13]ferrocenophane was a single compound, while the other three complexes were a mixture of two isomers. In the electronic spectra of the above series, the low-energy band shifted to the long-wavelength region and increased its absorbance according to the decrease in the size of the thiamacrocycle.