bluuebunny/crossref_metadata_2025_split huggingface dataset:
Anomalous Near Infrared Emission Observed in High Energy Electron Excited Xe and Xe–Ar
Authors: Tanaka Masako , Sasaki Susumu , Katayama Meiseki 
Published: July 2006

Abstract
The near infrared emission spectra of Xe and Xe–Ar which were excited by the pulsed irradiation of electrons by using a 45 MeV linear accelerator were investigated. A new broad band, probably due to the transition between the upper molecular states, was observed at 1200 to 1400 nm. The effects of O2 and SF6 on this band were studied.
The Osmotic and Activity Coefficients of Quaternary Phosphonium Halides in Aqueous Solutions at Freezing Point
Authors: Wakabayashi Toshiki , Takaizumi Katsuko 
Published: July 2006

Abstract
The osmotic and activity coefficients have been obtained cryoscopically for (n-Bu)4−nPhnPX(n=0–4, X=Cl, Br) in aqueous solutions at freezing point. The γ± decreases with increasing n, for both the chloride and the bromide salts. With the chloride salts, γ±’s for the salts of n from 0 to 2 show positive deviation from the Debye-Hückel limiting law as concentration increases, whereas γ±’s for others show negative deviation. Replacement of the anion from Cl− to Br− results in lower γ±’s for the salts of n from 0 to 2, but this elevates the other γ±’s. These results were interpreted qualit tively in terms of the cosphere overlap model by Desnoyers et al., by assuming a hydrophilic character of the present phenyl group. An attempt was made to evaluate the pairwise interaction coefficients(B*) and to estimate the contributions to B* from the interactions, butyl-Cl− and phenyl-Cl−.
Reactions of Azepine, Diazepine, Tropone, and Cyclopentadienone Derivatives with Some Chlorosilane Derivatives in the Presence of Magnesium
Authors: Saito Katsuhiro , Kojima Hisashi , Okudaira Tsuguo , Takahashi Kensuke 
Published: July 2006

Abstract
The reaction of 1-ethoxycarbonyl-1H-azepine with chlorosilane derivatives in HMPA in the presence of magnesium afforded the silanol derivatives, which upon heating gave the corresponding siloxane derivatives. In the same manner, tropone and 2,5-dimethyl-3,4-diphenylcyclopentadienone afforded the reduced dimers of them. However, tetraphenylcyclopentadienone and 2,5-dimethoxy-3,4-diphenylcyclopentadienone were reduced to the corresponding cyclopentenones under the reaction conditions. These reactions are considered to proceed via the corresponding radical anions which are formed by electron transfer from magnesium.
A Route from 1,1,1,3-Tetrachloro-3-phenylpropane to Ethynyl Phenyl Ketone Involving Elimination of Hydrogen Chloride and 1,3-Proton Transfer
Authors: Akiyama Takeo , Yoshida Yasuki , Hanawa Tokiko , Sugimori Akira 
Published: July 2006

Abstract
The treatment of 1,1,1,3-tetrachloro-3-phenylpropane with alkali in ethanol affords ethynyl phenyl ketone and its acetal in good yields. This reaction proceeds through the elimination of hydrogen chloride and an efficient 1,3-proton transfer catalyzed by base. Ethyl cinnamate is obtained in only 2% yield.
Kinetics of Oxidative Coupling of Phenols. Oxidation of Guaiacol by Alkaline Hexacyanoferrate(III)
Authors: Singh Sukham Nabakishwar , Bhattacharjee Mitra , Mahanti Mahendra Kumar 
Published: July 2006

Abstract
The reaction between guaiacol and alkaline hexacyanoferrate(III), at constant ionic strength, gave a coupled product, 3:3′-dimethoxydiphenoquinone. The rate of the reaction was dependent on the first orders of the concentrations of substrate, oxidant, and alkali. The rate determining step involved the formation of a radical intermediate, which was detected by ESR spectroscopy.
Solid State Reactions of 2,4-Dinitrotoluene. Detection and Semiquantitative Determination of Indole, Diphenylamine, and p-Dimethylaminobenzaldehyde
Authors: Nabi Syed Ashfaq , Mohammad Ali , Qureshi Pushkin Mohammad 
Published: July 2006

Abstract
Solid state colour reactions of 2,4-dinitrotoluene have been used for the selective detection of organic compounds and semiquantitative determination of indole, p-dimethylaminobenzaldehyde and diphenylamine in a glass capillary. Phloroglucinol and tryptophan do not interfere with the determination of indole. A glass wool plug modification makes the selective test almost specific for indole.
Direct Measurement of the Interaction Energy between Solids and Gases. X. Acidic Properties of Hydroxyl Sites of H–Y Zeolite Determined by High-temperature Calorimetry
Authors: Mitani Yoshio , Tsutsumi Kazuo , Takahashi Hiroshi 
Published: July 2006

Abstract
Differential heats of adsorption of bases on H–Y zeolite were measured at 473 K and separated into those evolved at 3640 and 3550 cm−1-OH sites respectively by a combined use of calorimetric and IR measurements, and then the acid strength of two OH sites was compared each other. In case of pyridine, heats of adsorption were larger on OH sites at 3640 cm−1 than 3550 cm−1, which was in agreement with the results obtained by many authors by IR measurements. However, heats of adsorption on 3640 cm−1-OH sites were only slightly higher than those on 3550 cm−1-OH sites in case of ammonia, and almost the same in case of piperidine. The difference in heats of adsorption between the OH sites was explained by positional difference between the two OH sites, molecular size of the titrated bases and proton mobility induced by a strong base. The order of the strength of bases was determined by replacing a base molecule with another one on H–Y zeolite as follows; piperidine&gt;pyridine&gt;ammonia. This differs from the order expected from their pKa values in solution.
Competitive Effects in Polymer Adsorption and Exchangeability of Adsorption Layer
Authors: Furusawa Kunio , Yamamoto Kazuaki 
Published: July 2006

Abstract
Critical experimental data on competitive adsorption and exchangeability of adsorbed polymer are produced under the various conditions using the gel permeation chromatography technique. It is apparent that the competitive effects and the exchangeability were found to depend not only on the molecular weight of the polymer, but also on the concentration of each component at which the corresponding adsorption is carried out. This can be explained as follows; the conformation of the adsorbed polymer would be influenced extensively by the polymer concentration in bulk. The polymer molecules adsorbed from a dilute solution would take on a flat conformation being rich in train segments, but the polymer layer formed under a concentrated solution would occupy a small of sites and adopt an extended loop configuration which would be desorbed more easily than the flat one. Also, in the mixed sample the effects of adsorption Kinetics play an important role on the structure of the adsorption layer, because at first the surface is convered by an adsorption layer of small components due to its rapid adsorption rate.
Crystal and Molecular Structure of (+)-(3R,4S,8R,9S)-Quinidinium Δ-(−)546-Bis(oxalato)(1,10-phenanthroline)chromate(III) Monohydrate and Its Implication in the Pfeiffer Effect of the Corresponding System
Authors: Ohbo Hiroyuki , Okazaki Hiroshi , Miyoshi Katsuhiko , Yoneda Hayami 
Published: July 2006

Abstract
The crystal structure of the title compound d-quinidinium (−)546-[Cr(ox)2(phen)]·H2O has been determined by a single-crystal X-ray analysis and refined to R=0.078 for 2172 reflections. The crystals are orthorhombic, space group P212121 with unit cell dimensions of a=9.943(2), b=11.265(2), c=30.716(6) Å, and Z=4. The known configurations of d-quinidinium ion revealed that (−)546-[Cr(ox)2(phen)]− has a Δ configuration in accord with the earlier assignment based on its CD spectrum. Following characteristics were noted with regard to intermolecular interactions in the crystal; i) complex anions are linked with one another through the hydrogen bonds to intervening water molecules, to form chains along two-fold screw axes parallel to the a-axis, ii) intermolecular hydrogen bonds connect the complex anion closely with d-quinidinium cation which is further hydrogen-bonded to each other forming infinite chains along two-fold axes parallel to the b-axis, and iii) partial stacking is observed between aromatic phen and quinoline rings. These interaction modes were discussed in relation to the Pfeiffer Effect of the corresponding system in water.
Synthesis of Some New Aza Tricyclic Compounds with a Cyclopropane Ring via Photolysis of Dihydromayurone Oximes and the Related Compounds
Authors: Takahashi Hajime , Ito Masaaki 
Published: July 2006

Abstract
Oximation of dihydromayurone and 6,10,10-trimethyltricyclo[4.4.0.01,3]decan-4-one gives new isomeric oximes, respectively. The Beckman rearrangement of (Z)- or (E)-dihydromayurone oxime and (Z)- or (E)-6,10,10-trimethyltricyclo[4.4.0.01,3]decan-4-one oxime with polyphosphoric acid takes place prior to the Z-E equilibration of these isomers, respectively. Photolysis of the oximes gives two pairs of the isomeric lactams, 4-aza-8,12,12-trimethyltricyclo[6.4.0.01,3]dodecan-5-one, 5-aza-8,12,12-trimethyltricyclo[6.4.0.01,3]dodecan-4-one, 4-aza-7,11,11-trimethyltricyclo[5.4.0.01,3]undecan-5-one, and 5-aza-7,11,11-trimethyltricyclo[5.4.0.01,3]undecan-4-one. The reaction of either dihydromayurone or 6,10,10-trimethyltricyclo[4.4.0.01,3]decan-4-one with hydroxylamine-O-sulfonic acid in acetic acid affords only the lactam arising from the migration of the less substituted carbon.
Double Cycloaddition Reaction of Imidazolium Methylides. Intermolecular 1,3-Dipolar and Intramolecular Diels-Alder Cycloaddition Reactions
Authors: Tsuge Otohiko , Kanemasa Shuji , Takenaka Shigeori 
Published: July 2006

Abstract
Such imidazolium methylides as imidazolium dicyanomethylide and bis(ethoxycarbonyl)methlide react with the methylenecyclopropenes with unsaturated substituents at the 4-position in the fashion of double cycloaddition reaction, leading to the novel cage compounds, which involves an intermorecular 1,3-dipolar cycloaddition reaction and an intramolecular Diels-Alder reaction.
Pseudo-sugars. X. Synthesis of Several Branched-chain Unsaturated Cyclitols and Their Derivatives
Authors: Ogawa Seiichiro , Hattori Takao , Toyokuni Tatsushi , Suami Tetsuo 
Published: July 2006

Abstract
Some racemic (hydroxymethyl)cyclohexenepolyols and their derivatives of biological interest have been synthesized from Dl-1,2,3-tri-O-acetyl-(1/2,3)-4-methylene-5-cyclohexene-1,2,3-triol derived from the corresponding dibromide by treatment with sodium acetate in hexamethylphosphoric triamide.
IR Spectra of Solid State Reaction Products of TTF and Iodine
Authors: Matsuzaki Susumu , Koga Naoto , Moriyama Ichiro , Toyoda Koichi 
Published: July 2006

Abstract
IR spectra of the mixture of tetrathiafulvalene (TTF) and iodine showed that the two components react with each other in the solid state. Spectral changes with an increase in iodine content were analyzed on the basis of the spectra of TTF and the cations, and it was found that TTF is oxidized by iodine up to the dication in the solid state in contrast to the reaction in solution.
Oxygen Evolution Reaction on Composite Cobalt Borides
Authors: Osaka Tetsuya , Iwase Yoshio , Kitayama Hiroshi , Ichino Toshihiro 
Published: July 2006

Abstract
The Oxygen evolution reaction on cobalt borides and composite cobalt borides was investigated in a 6M KOH solution (1 M=1 mol dm−3) using the factor of the magnetic properties. In the system of cobalt borides (Co:B=3:1) prepared at various sintering temperatures, the boride having a higher saturation magnetization revealed a higher activity of the oxygen evolution reaction. In the system of composite cobalt borides which have various magnetic moments, μB, a clear correlation between the activity of the oxygen evolution reaction and the saturation magnetization (or magnetic moment, μB) was observed for several composite cobalt boride species (i.e., Co–Fe–B, Co–Ni–B, Co–Mn–B, and Co–B). Among the composite cobalt boride species, the cobalt iron boride (Co:Fe:B=1:2:1) sintered at 450 °C showed the highest activity of oxygen evolution reaction in a 6 M KOH solution. The conditions of oxide formation on Co–Fe–B(1:2:1) and on Co–B(3:1) in a 6 M KOH solution were compared with those on cobalt by means of voltammetry and chronopotentiometry. It was concluded that the ease and stability of oxide films in higher oxidation states are strongly correlated to the activity of the oxygen evolution reaction which occurs on more highly oxidized oxide films.
Crystal and Molecular Structure of Methyl d-Tetronitroside
Authors: Hirayama Noriaki , Kasai Masaji , Shirahata Kunikatsu , Ohashi Yuji , Sasada Yoshio 
Published: July 2006

Abstract
The structure of the novel sugar, methyl d-tetronitroside [methyl 2,3,4,6-tetradeoxy-4-(methoxycarbonylamino)-3-C-methyl-3-nitro-d-xylo-hexopyranoside], was determined by X-ray analysis. This compound is a structural component of the antitumor antibiotics, tetrocarcins. The space group is P21 with a=11.782(3), b=10.271(2), c=11.636(3) Å, β=105.12(4)°, and Z=4. The structure was solved by direct methods, and least-squares refinement using 2503 reflexions gave the final R value of 0.079. Both the two independent molecules take a 4C1 chair conformation and they are connected together through two hydrogen bonds. Although the average C–C distance in the rings is 1.527 Å, the C(2)–C(3) distance is significantly long (average 1.546 Å) due to the steric hindrance by the nitro groups.
The Structure of Liquid Formamide Studied by Means of X-Ray Diffraction and ab Initio LCGO-MO-SCF Calculations
Authors: Ohtaki Hitoshi , Funaki Atsushi , Rode Bernd M , Reibnegger Gilbert J 
Published: July 2006

Abstract
The molecular and liquid structures of formamide have been studied by means of X-ray diffraction. Relative stabilities of aggregates of formamide molecules have been calculated by using the ab initio LCGO-MO-SCF procedure and minimal basis sets. The atomic distances within a formamide molecule and the intermolecular N···O distance between the hydrogen–bonded molecules are determined by the X-ray diffraction experiment as follows: C=O: 1.24(1) Å, C–N: 1.33(1) Å, N···O (intramolecular): 2.25(2) Å, and N···O (intermolecular): 3.05(5) Å. The intermolecular (Remark: Graphics omitted.) bond angle (Θ) is about 120°. It is concluded from the X-ray diffraction experiment that liquid formamide mainly consists of the chain-like hydrogen–bonded structure of formamide molecules by combining through –NH2···O=CH– interactions. The conclusion is supported by the ab initio calculations. Formation of ring-dimers in the liquid formamide has not been confirmed by the X-ray diffraction study, although a possibility of the formation of the ring-dimer structure as another constituent of liquid formamide is suggested from the ab initio calculations.
Determination of Diffusion Coefficients of Metals Dissolved in Mercury by Double Potential Step Chronoamperometry at Hanging Mercury Drop Electrodes
Authors: Park Sang Yun , Aoki Koichi , Tokuda Koichi , Matsuda Hiroaki 
Published: July 2006

Abstract
Double potential step chronoamperometry at the hanging mercury drop electrode is proposed for determination of diffusion coefficients of metals dissolved in mercury. The expression for chronoamperometric curves is obtained, from which the algorithm is derived for evaluating diffusion coefficients of metals. The diffusion coefficients of lead, zinc, and cadmium in mercury at 25 °C were determined by the present technique.
Polarography of Pb(II) Complexes with N,N′-Bis(2-hydroxyethyl)ethylenediamine-N,N′-diacetic Acid
Authors: Matsuo Tsutomu , Masuda Yoshitaka , Sekido Eiichi 
Published: July 2006

Abstract
The electrochemical behaviour of the Pb(II)–N,N′-Bis(2-hydroxyethyl)ethylenediarnine-N,N′-diacetic acid(H2bhedda=H2L) system has been examined by means of d.c. polarography. Two well-defined polarographic reduction waves were observed. The mechanisms of the electrode reaction for the two waves were elucidated. The kinetic parameters of the irreversible reduction of the complexes have been evaluated; kj1=3.80×10−5 cm/s and kj2=5.25×10−16 cm/s. The stability constant of the PbHL+ species is calculated to be 104.45.
Preparation and Properties of Polymers Anchoring Biphenyl-2-ol
Authors: Ishikawa Tomomichi , Asai Satoshi 
Published: July 2006

Abstract
The monomer, 2-biphenylyl acrylate (BPA), was prepared and was polymerized and copolymerized with vinyl acetate (VAc), styrene and N-vinylpyrrolidone. The reactivity ratios of BPA (M1) with VAc were evaluated as r1=4.6+0.4 and r2=0.37+0.08. The polymers were hydrolyzed in methanol–phosphate buffer solution(pH 6 and 8), and the release rate of biphenyl-2-ol from the polymer was investigated.
NMR Study of Protonated Halothiophenes. I. 1H NMR Study of Chlorothiophenium Ions
Authors: Yokoyama Yukihiro , Yamashita Yukihide , Takahashi Kensuke , Sone Tyo 
Published: July 2006

Abstract
Well-resolved 1H NMR signals of the cations formed from chlorothiophenes were observed in the HSO3F or AlCl3–HCl–CH2Cl2 system. Chlorothiophenes are protonated exclusively at the position adjacent to sulfur, either with or without substituents. The protonation of 2-chloro-5-methylthiophene occurs at the 5-position, and, in the HSO3F system, the cation 5H-2-chloro-5-methylthiophenium ion thus formed undergoes an irreversible 2,5-hydrogen shift.
Reaction of 1,8-Naphthalenediamine with Dimethyl and Diethyl Acetylenedicarboxylates
Authors: Honda Koichi , Nakanishi Hiroshi , Yabe Akira 
Published: July 2006

Abstract
1,8-Naphthalenediamine reacted with dimethyl and diethyl acetylenedicarboxylates, giving rise to tetrahydronaphtho[1,8-ef]diazepinones (2), dihydroperimidines (3) and bis(enamino)fumarates (4). The relative yields of 3 and 4 depended on the reaction conditions, while products 2 were always very minor. Products 4, the yields of which increased considerably in the presence of a large excess of the acetylenes, underwent cyclization at 230 °C leading to quinolinoquinolinediones.
Behavior of Trajectory with Stable and Unstable Limit Cycles in the Oregonator Model for the Belousov-Zhabotinskii Reaction
Authors: Sakanoue Shinji , Murase Chiaki , Endo Mitsuo 
Published: July 2006

Abstract
Computer simulations and a theoretical analysis of the Oregonator model of the Belousov-Zhabotinskii reaction are made based on Tyson’s equation. The behavior of the amplitudes of the unstable limit cycle near the transition point, pc, can be explained theoretically fairly well by the Landau theory. The global behavior of one stable limit cycle and one unstable limit cycle is examined by means of simulations. The existence of a triple point at which three different global states coexist has been suggested.
Acid-Base and Catalytic Properties of ZrO2–SnO2
Authors: Wang Gong-Wei , Hattori Hideshi , Tanabe Kozo 
Published: July 2006

Abstract
The acid-base properties of ZrO2–SnO2 with different compositions have been measured by the indicator method and the adsorption with NH3 and CO2 and the catalytic activities studied. The ZrO2–SnO2 (atomic ratio=9 : 1) catalyst which was found to have the highest acid strength and the maximum acid amount exhibited the highest activities for the isomerization of cyclopropane and the dehydration of 2-butanol. The activities of the catalysts with different compositions for the two reactions correlated with the acidic properties. On the other hand, the activities for the isomerization of 1-butene and the decomposition of diacetone alcohol (4-hydroxyl-4-methyl-2-pentanone) correlated with the basic properties. The activity for the dehydrogenation of 2-butanol was found to increase with an increase of the SnO2 content. The active sites on the ZrO2–SnO2 catalysts are discussed.
Emission Spectra of Toluidines by Controlled Electron Impact
Authors: Ogawa Teiichiro , Oomori Takayuki , Kawazumi Hirofumi 
Published: July 2006

Abstract
The spectra of o-, m-, and p-toluidines show an intense band of the S1-S0 transition of the parent molecule, and lines and bands of fragment species such as H, CH, C2, CN, and NH.
The Heats of Solution of Optically Active Amino Acids, the Corresponding Racemic Amino Acids, and Their Derivatives in Water
Authors: Matsumoto Masayuki , Amaya Kazuo 
Published: July 2006

Abstract
The heats of solution of normal and branched α-amino acids and of their derivatives in water were measured at 298.15 K. The experimental results show that the racemates are more stable than optically active compounds, except for glycylleucine, and that the differences in the heat of solution between the two species for branched compounds are nearly constant, about 2 kJ mol−1, while those for the normal compounds are dependent on the number of carbon atoms in the alkyl chains.
Thermally Derived Dimers of o-Vinylphenol: trans- and cis-2′-Hydroxy-4-methylflavans
Authors: Chen Yen-Yuan , Oshima Ryuichi , Kumanotani Ju 
Published: July 2006

Abstract
o-Vinylphenol dimerizes thermally to yield quantitatively two isomers, trans- and cis-2′-hydroxy-4-methylflavans. The analysis of the dimers of o-vinylphenol-O-d suggests that a quinone-methide intermediate is responsible for the formation of these flavanoid compounds.
Enrichment and Determination of Trace Amounts of Iron as the Colored Complex on the Thin Layer of Ion-exchange Resins
Authors: Ohzeki Kunio , Satoh Yuhko , Kawamura Yoshito , Kambara Tomihito 
Published: July 2006

Abstract
A trace amount of iron was extracted as the complex with 4,7-diphenyl-1,10-phenanthrolinedisulfonic acid from aqueous solution using finely divided anion and cation exchange resins. The mixed resins were collected on a filter paper as the disk of thin layer. The colored complex in the resin phase was determined with the use of a densitometer at 540 nm. The calibration graph was linear over the range 0.1–0.5 μg of iron(II). The relative standard deviation for 0.5 μg of iron(II) in 50 ml of the test solution was 2.1% (n=5). The method was applied to the trace determination of total iron in water samples.
The Synthesis and Reaction of Spiro[oxolane-2,2′-piperazine]-3′,6′-diones with N-Bromosuccinimide in the Presence or Absence of Water
Authors: Shin Chung-gi , Sato Yoshiaki , Honda Seiji , Yoshimura Juji 
Published: July 2006

Abstract
The compound 3-(3-hydroxy)propylidene-piperazine-2,5-dione, derived from ethyl 4-ethoxycarbonyl-2-chloroacetylamino-2-butenoate, was treated with N-bromosuccinimide (NBS) in chloroform to give the spiro[oxolane-2,2′-piperazine]-3′,6′-dione derivative. The spiro compound was further treated with NBS in water to give the corresponding spiro[oxolane-2,2′-piperazine]-3′,5′,6′-trione and -3′,6′-dione-5′-ol. The latter compound and a new spiro-5′,6′-dione-3′-ol derivative were also obtained by the reduction of the spiro-3′,5′,6′-trione. The structural confirmation of all the new products is discussed.
Asymmetric Hydrogenations of N-Pyruvoyl-(S)-amino Acid Esters
Authors: Harada Kaoru , Munegumi Toratane 
Published: July 2006

Abstract
N-[(R)-Lactoyl]-(S)-amino acid isobutyl esters were obtained with a diastereoisomeric purity up to 34%, through the catalytic hydrogenations of N-pyruvoyl-(S)-amino acid (alanine, valine, and leucine) isobutyl esters over palladium on charcoal. It was found that a linear correlation exists between the dielectric constant of the solvent and the diastereoisomeric purity of the product obtained by catalytic hydrogenation. The ratio of N-[(S)-lactoyl]-(S)-amino acid isobutyl ester to N-[(R)-lactoyl]-(S)-amino acid isobutyl ester increased with the decrease of the dielectric constant of the solvent. This solvent effect could be explained by the chelation mechanism. The temperature effect on the asymmetric catalytic hydrogenation was also studied.