bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Spectroscopic Observation of the Selective Volatilization of Metal Solid Samples in a Nitrogen Plasma Flame
Authors: Oku Masaoki , Hirokawa Kichinosuke 
Published: July 2006

Abstract
Some metal solid samples were burned in a nitrogen plasma flame, and the spectrum intensity-time curves were spectrographically observed. The curves indicated that the fractional distillation of alloying elements was caused by the reactions of the solid-alloy sample and nitrogen gas. The fractional distillation was explained in terms of the difference in the stabilities of the metal nitrides. The distribution of the emission species and the temperature of the flame suggested that there were few chemical reactions in the flame or that the chemical reactions in the flame had little effect on the spectrum intensities. In an appendix, the method of line-pair selections for obtaining the correct temperature is considered.
Photon-Activation Analysis for Zirconium with Molybdenum Used as the Internal-Reference Element
Authors: Pung Tong-Chuin , Kato Toyoaki , Oka Yoshinaga 
Published: July 2006

Abstract
A method for the determination of zirconium has been studied by activation analysis with bremsstrahlung photons, with molybdenum used as the internal-reference element. This method is based on the γ-ray spectrometric measurement of the 89Zr activity produced by the 90Zr(γ,n) reaction and on the comparison of this activity with the 88Zr activity formed by the (γ,α) reaction on molybdenum. The reaction products and their rates of production in zirconium and in molybdenum have also been examined as functions of bremsstrahlung maximum energies up to 60 MeV, and the best conditions for the determination of zirconium are proposed. When the maximum energy was set at 20 MeV, no interfering reactions occurred; under the present experimental conditions, a zirconium content down to about 18 μg can be determined accurately. The reliability and the versatility of this method are demonstrated.
Studies of Ethylenediamine-N,N′-diacetatocobalt(III) Complexes. I. The Preparation and Some Properties of Ethylenediamine-N,N′-diacetatocobalt(III) Complexes, with Chloride, Water, Ammonia, Ethylenediamine, 1,10-Phenanthroline, and 2,2′-Dipyridyl as the Additional Ligands
Authors: Kuroda Kashiro , Watanabe Kiyokatsu 
Published: July 2006

Abstract
A series of cobalt(III) complexes containing the tetradentate ethylenediamine-N,N′-diacetate anion (EDDA) and chloride, water, ammonia, ethylenediamine, 1,10-phenanthroline, and 2,2′-dipyridyl as the ligands occupying the residual coordination positions have been prepared, and some of their physical and chemical properties have been examined. Two isomers have been isolated in the cases of the phenanthroline and dipyridyl complexes; they have been inferred to be the α-cis(pink) and the β-cis(red) isomers on the basis of their electronic absorption spectra. A new convenient route for the preparation of the series has been presented, a route which passes through the dichloro, chloroaquo, and diaquo complexes.
Synthesis and Properties of Two α-Phenylazostilbenes. A New Method for the Elimination of Water and p-Toluensulphonate Ion from Substituted Phenylhydrazones
Authors: Caglioti Luciano , Giumanini Angelo G 
Published: July 2006

Abstract
The synthesis of a linear azoalkene, α-phenylazostilbene (1), not conjugated to strong electron withdrawing groups is reported. α-(p-Methoxyphenylazo)stilbene (3) was prepared by a direct method. The mass spectra of 1 and 3 showed a rearrangement yielding positive ions of benzonitrile and benzaldehyde anils (7).
Anodic Reaction of 5-Alkyl-2-furoic Acids in Protic Solvents
Authors: Torii Sigeru , Tanaka Hideo , Ogo Hitosi , Yamasita Siro 
Published: July 2006

Abstract
Anodic oxidation of 5-alkyl-2-furoic acids (4 and 10) in protic solvents has been studied. The major products were 1-butenolides (12, 13, 16, and 17) and γ-keto esters (11 and 15) and their acids (14 and 18). Methyl 5-n-hexyl-2,5-dimethoxy-2,5-dihydro-2-furoate 19 was converted into γ-keto ester 11 and its acid 14 by hydrolysis with alkali and into 1-butenolide 12 by electrolysis of the alkaline solution. A possible mechanism of the anodic oxidation of 5-alkyl-2-furoic acids has been discussed.
Photochemical Reduction of Nitrobenzene and Its Reduction Intermediates. IX. The Photochemical Reduction of 4-Nitropyridine in a Hydrochloric Acid-Isopropyl Alcohol Solution
Authors: Hashimoto Shizunobu , Kano Koji , Ueda Kazuo 
Published: July 2006

Abstract
The photochemical reduction of 4-nitropyridine has been investigated in hydrochloric acid-isopropyl alcohol solutions. 4-Nitropyridine was not photoreduced in isopropyl alcohol, whereas when the photolysis was carried out in hydrochloric acid-isopropyl alcohol solutions, the photoreduction of 4-nitropyridine proceeded from its n,π* triplet state to give 4-hydroxylaminopyridine in a quantitative yield. The quantum yields for the disappearance of 4-nitropyridine in hydrochloric acid-isopropyl alcohol solutions increased with the concentration of hydrochloric acid up to 3.6×10−2 mol l−1 (Φ=0.27–0.94). These results suggest that the hydrogen abstraction of photoexcited 4-nitropyridine proceeds electrophilically because of the decrease in the electron density of the nitro group, in decrease resulting from the protonation of heterocyclic nitrogen and the n,π* excitation of the nitro group.
Oligomerization of Isoprene by Vanadium Catalysts
Authors: Uchida Yasuzo , Furuhata Ken-ichi , Ishiwatari Hisayasu 
Published: July 2006

Abstract
Oligomerization of isoprene by the catalyst system consisting of VO(OEt)3 and organoaluminum compounds was studied. Isoprene was oligomerized to a mixture of dimers, trimers and higher oligomers by VO(OEt)3–Et2AlCl catalyst system. 2,6-Dimethyl-1,trans-3,6-octatriene was the main dimer of isoprene in this reaction. The addition of tetrahydrofuran, dioxane, triphenylphosphine, bis-diphenylphosphinoethane, triethylamine or tetramethylethylenediamine to this catalyst system raised the reaction rate and the selectivity for the dimer at lower donor/VO(OEt)3 molar ratios but suppressed the reaction at higher molar ratios. By VO(OEt)3–Et3Al catalyst system, isoprene was converted to a liquid polymer and by VO(OEt)3–EtAlCl2 catalyst system, it was cyclopolymerized to an insoluble polymer. Structures of two new oligomers of isoprene were also reported.
The Reactions of Dihalogenoalkanes with Dimethyltin Bis-(N,N-dimethyldithiocarbamate) and Related Compounds
Authors: Tanaka Toshio , Tanaka Koji , Yoshimitsu Tokio 
Published: July 2006

Abstract
Dimethyltin-bis(N,N-dimethyldithiocarbamate), (CH3)2Sn[S2CN(CH3)2]2, reacts with dihalogenoalkanes to give 1,3-dithiacycloalkyl-2-dimethylimminium dimethyltin halides, (Remark: Graphics omitted.) (n=1 or 2; m=2, 3, or 4; X=Cl, Br, or I). On the other hand, the reactions between dimethyltin bis(N-methyl-N-phenyldithiocarbamate), (CH3)2Sn[S2CN(CH3)(C6H5)]2, and dihalogenoalkanes yield preferentially alkylene bis(N-methyl-N-phenyldithiocarbamate). The difference in reactivity between the two types of complexes is discussed. The infrared and NMR spectra indicate that the positive charge on the dithiacycloalkylimminium ions is more delocalized in the higher homologues. The configurations of dimethyltin trihalide and tetrahalide anions in the solid state and in solution are also presented on the basis of the infrared spectra; the results suggest that, in solution, dimethyltin trihalide anions are more likely to be formed than are dimethyltin tetrahalides.
The Pyrolysis of Halocyclopropanes at High Temperatures
Authors: Asahara Teruzo , Ono Katsumichi , Tanaka Kazuki 
Published: July 2006

Abstract
The pyrolysis reactions of dihalocyclopropanes and monohalocyclopropanes were carried out at 200–400°C. Bromo-substituted cyclopropanes were readily decomposed in this temperature range. In all cases, the pyrolysis products were ring-opened olefinic hydrocarbons. As for the monohalocyclopropanes, the reactions proceed in a stereospecific manner. The possible mechanism was discussed in terms of the requirements of the electrocyclic ring opening.
A Theoretical Study of the Possible Interaction between Sulfonium Salts and Molecular Oxygen
Authors: Ohkubo Katsutoshi , Yamabe Tokio 
Published: July 2006

Abstract
The interaction between sulfonium salts and molecular oxygen was studied by the ASMO SCF method. Firstly, the results of the ASMO SCF calculation of trimethylsulfonium chloride suggested that the bond between the sulfonium cation and the anion was constituted mainly of the bonding (d-p)π-type overlaps (made by 3dyz-(or 3dxz-) of S and 3py (or 3px) of Cl) and of the antibonding (d-p)σ-type overlaps (made by 3dz2 (or 3pz) of S and 3pz (or 3dz2) of Cl). Secondly, the sulfonium salt interacts with molecular oxygen mainly through a (d-p)σ-type overlap between the 3dyz-(or 3dxz-)orbital of the former and the (1πg)z-orbital of the latter. Thirdly, a maximum overlap formed between 3d-sulfur orbitals and 1πg-orbitals of O2 is established at the O2-rotation angle of π/4 to the direction of the d-orbital expansion. Finally, the change in the energy state of O2 caused by the sulfonium-salt interaction was discussed.
Kinetics and Mechanism of Aquation and Anation of Some Amino Acid Pentamminecobalt(III) Complexes in Acid Aqueous Solutions
Authors: Murakami Tasuku , Ogino Kazuko , Kobayashi Hiromi , Yamazaki Hiroshi , Saito Kazuo 
Published: July 2006

Abstract
Kinetics of aquation has been studied with pentamminecobalt(III) complexes containing aliphatic amino acids (γ-aminobutyric acid, ε-aminocaproic acid, α-amino-isobutyric acid, ornithine, and proline), aromatic acids (benzoate, anthranilic, and p-aminobenzoic acid), and α-substituted acetates (monochloroacetate and glycolate). Anation rate constants were obtained for glycine, β-alanine, and ε-aminocaproic acid, and equilibrium constants between [CoH2O(NH3)5]3+ and [Co(NH3)5amH]3+ (amH=amino acid), Keq were calculated. The free energy plot logkaq vs. logKeq gave a straight line with a gradient 0.6. This value has been discussed in terms of two possible mechanisms. The dependence of acid catalysed aquation rate constant, kH+ on pKa of carboxylate group of the amino acid is written as logkH+=0.5 pKa+ const., while that for α-substituted acetates log kH+=pKa+ const. Such a difference in the slope is interpreted as due to the electrostatic influence of–NH3+ group of coordinated amino acid.
Ultrasonic and Thermodynamic Study on Solute-Solvent Interaction. Binary Mixtures of t-Butyl Chloride, t-Butyl Bromide and 1,1,1-Trichloroethane with Carbon Tetrachloride, Benzene and p-Xylene
Authors: Kiyohara Osamu , Arakawa Kiyoshi 
Published: July 2006

Abstract
Sound velocity and density of binary mixtures of t-butyl chloride (tBC), t-butyl bromide (tBB), and 1,1,1-trichloroethane (TCE) with carbon tetrachloride (CT), benzene (B), and p-xylene (pX) were measured at temperatures, 25 and 35°C. The excess molar volume and excess compressibility of these systems were calculated. The temperature dependency of excess volume was negative for aromatic solutions and positive for CT solutions. The temperature coefficients of excess compressibility were negative for all systems. The relation between thermodynamic properties and intermolecular interactions in these systems were discussed. Two systems, B-TCE and CT-TCE, were found to be nearly ideal. The solute-solvent interactions in CT-tBC and tBC-TCE systems were found to be more attractive than in other systems.
The Crystal Structure of cis-Ammonium Disulfitotetramminecobaltate(III) Trihydrate, NH4[Co(SO3)2(NH3)4]·3H2O
Authors: Nomura Teruo , Nakahara Masayoshi 
Published: July 2006

Abstract
The structure of NH4[Co(So3)2(NH3)4]·3H2O has been determined by the heavy-atom method and refined to R=0.12 by a least-squares analysis based on 874 three-dimensional visual data. The compound crystallizes in the orthorhombic space group P212121 with unit cell dimensions of a=10.995, b=17.563, c=6.834 Å, and Z=4. The two sulfito groups in the complex anion are coordinated to the central cobalt atom in cis positions through their sulfur atoms, with Co-S distances of 2.23 Å (mean). The cis-configuration of brown sodium salt, with an absorption spectrum similar to that of the trihydrate of ammonium salt, has also been established.
The Surface Properties of the Silica-Titania System Prepared by the Hydrolysis of Metal Alkoxides
Authors: Hosaka Hiroshi , Meguro Kenjiro 
Published: July 2006

Abstract
The surface and bulk properties of silica-titania systems, prepared by the co-hydrolysis of silicon ethoxide and titanium tetrabutoxide, were investigated by measuring the heat of immersion, the adsorption of nitrogen, water, and ammonia, the X-ray diffraction, the DTA, and the TGA. It was found that the addition of silica to titania has a large suppressive effect on the crystal growth of anatase and on the transformation of anatase to rutile. The heat of immersion, the surface hydrophilicity (the surface area by water adsorption/the surface area by nitrogen adsorption) and the amount of ammonia adsorbed gave inverted sigmoid curves when the titania content was varied. Especially, the shape of the curve of the change in the heat of immersion coincides approximately with that of the surface hydrophilicity.
Photochemical Reaction of 9-Cl-Acridine in Aerated and Deaerated Ethanol. I
Authors: Nakamaru Katsumi , Niizuma Shigeya , Koizumi Masao 
Published: July 2006

Abstract
It was established that upon irradiation, the degassed ethanol solution of 9-chloroacridine is quickly converted into 9,9′-biacridyl by the reaction 2 (9-Cl-acridine) \overset+2H\underset(hν)→ 9,9′-biacridyl+2HCl and that 9,9′-biacridyl produced is then reduced photochemically to 9,9′-biacriden as the main product. The reaction scheme completely denies the scheme previously proposed (V. Zanker and W. Flügel, Z. Naturforsch., 19(b), 376 (1964)) in which the primary photoproduct is a charge transfer complex between 9-Cl-acridine and its reduced form. 9,9′-biacridyl is photoreduced to an acridan-like compound even in the aerated solution perhaps via molecular mechanism in contrast to 9-Cl-acridine which yields acridone under similar conditions. ESR spectrum with hfs was detected in the acidic solution (degassed) containing 9,9′-biacriden produced photochemically. The mechanism of its production was discussed. Similar reactions using various solvents (aerated and deaerated) were examined and the general feature of the primary processes was described.
The Crystal and Molecular Structure of Pyromellitic Acid Dihydrate (Benzene-1,2,4,5-tetracarboxylic Acid Dihydrate)
Authors: Takusagawa Fusao , Hirotsu Ken , Shimada Akira 
Published: July 2006

Abstract
The crystal structure of pyromellitic acid dihydrate has been determined by the method of X-ray diffraction. The crystal is triclinic in the P\bar1 space group, with Z=1 and cell dimensions of a=10.05, b=6.45, c=5.45 Å, α=74.5°, β=112.2°, and γ=77.3°. The structure was derived from the three-dimensional Patterson function and was later refined by the least-squares method, using the anisotropic thermal parameters, to give a final R index of 7.4%. All the hydrogen atoms were located on the difference-synthesis map. The average C(ring)–C(ring) distance is 1.386 Å, while the average C(ring)–C(carboxyl) distance is 1.496 Å. One carboxyl group is twisted by 17.9°, and the other is twisted by 74.5°, out of the plane of the benzene ring. The C–O(H) and C=O distances differ significantly from each other, the average values being 1.302 and 1.211 Å respectively. Four types of hydrogen bonds, with an average O–H···O distance of 2.732 Å, form a three-dimensional network. Thus, each molecule is joined, through hydrogen bonds around the center of symmetry, to two other molecules, forming an endless chain in the [1 \bar1 1] direction. Water molecules are arranged on the plane parallel to (1 1 0) so as to hold the chains together by hydrogen bonds.
Photochemical Reactions of Uranyl Ions with Organic Compounds III. The Correlation between the Reaction Mode and the Pre-Equilibrium in the Photolysis of the Uranyl-lactate System
Authors: Sakuraba Shukichi , Matsushima Ryoka 
Published: July 2006

Abstract
On the basis of the assumed mechanism for the photolysis of the uranyl-lactate system, the equilibrium constant for the complex formation, K, was evaluated from the photo-kinetic data by using a monochromatic 4047 Å light; it was then compared with those obtained from the usual spectrophotomeric measurements. A comparison of the K values obtained by means of the photo-kinetic data (1.0–1.1×10−1) and by means of the analytical data (1.1–1.2×10−1) gave an excellent agreement; there was also a good agreement between the slope of the plot of the photo-kinetic data and that predicted from the assumed mechanism. The results supported the crude mechanism assumed earlier.
Stability Constants of Cu(II) Chelates with o-Phenylenediamine Derivatives
Authors: Kina Kenyu , Tôei Kyoji 
Published: July 2006

Abstract
The stability constants of copper(II) chelates with o-phenylenediamine derivatives have been determined by the pH titration method. The measurements have been carried out at 25.0±0.1°C and μ=0.10(by KNO3).
o-Phenylenediamine derivatives, which have a substituent group (CH3, CH3O, COOH, or Cl, etc.) at the 4 positions, were used as ligands. The overall stability constants of the copper chelates are of the order: CH3, CH3O, H, COO−, Cl, COOH; their values were 8.50, 8.42, 7.72, 7.06, 5.76, and 5.35 respectively. The effects of substituent groups on the stability constants have been studied. The plot of the overall stability constants against the sum of Hammett σm and σp values was found to be linear. The chelate stability and acid dissociation constants of the acido complexes of 3,4-diaminobenzoic acid were determined by the use of an augmented matrix.
The pH Dependence of Anion Exchange Chromatographic Separation of Tri- and Tetraphosphate Anions
Authors: Nakamura Terumasa , Kimura Mitsuyasu , Waki Hirohiko , Ohashi Shigeru 
Published: July 2006

Abstract
The anion-exchange distribution ratios of tri-, tetra-, and pentaphosphate were determined in a Dowex 1-X4-potassium chloride system at different pH by the batch method. The difference between the mean charges of the phosphates in resin phase and solution was explained in terms of a higher pH of resin phase than that of the solution. pH dependence of the separation factors for tri- and tetraphosphate and for tetra- and pentaphosphate was estimated from the batch equilibrium data, and the relative elution positions of these phosphates were confirmed by the practical chromatographic runs.
The Reaction of Acetylenecarboxylic Acid with Amines. XVI. Formation of Alkyl Isoxanthopterinacetates Possessing Imine Structure
Authors: Iwanami Yasuo 
Published: July 2006

Abstract
Methyl and ethyl isoxanthopterin-6-acetates and their 4-amino analogues have been prepared via a new route from acetylenedicarboxylate and 2,5,6-triamino-4-hydroxypyrimidine or 2,4,5,6-tetraaminopyrimidine. These compounds uniquely exist in the imine form as evidenced by NMR and IR spectral data. This is the only exceptional case so far examined, since a number of related compounds exist in enamine form. When dissolved in sulfuric acid, however, tautomerization of imine to enamine is observed. It was demonstrated by NMR inspection that the methylene hydrogen on the side chain is exchangeable with deuterium. The tautomerism in sulfuric acid is discussed.
Heterocycles Structurally Influenced by a Side Chain. I. 3-Phenacyl-2(1H)-quinoxalinones and 3-Phenacyl-2H-1,4-benzoxazin-2-ones
Authors: Iwanami Yasuo , Seki Taketsugu , Inagaki Takeshi 
Published: July 2006

Abstract
Seven phenacyl derivatives of 2(1H)-quinoxalinone and 2H-1,4-benzoxazin-2-one (IV and V) have been synthesized to introduce a common structural element –CH2–CO– into their 3-positions. Their structures are compared with those of the related compounds described previously. The main purpose of the present study was to see whether or not their ring double bonds ((Remark: Graphics omitted.)) have ever been displaced onto the side chains, constituting an enamine so as to form =CH–CO–, the carbonyl of which is hydrogen bonded with the secondary amino group of the rings thereby formed. Consequently, existence as the enamine form, facilitated by an intramolecular hydrogen bonding, has been evidenced by IR and NMR spectral data. It is, therefore, fitting to call them by the more practical expression “3-phenacylidene-3,4-dihydro-2(1H)-quinoxalinone” (IVa), and so on. Hydrolysis of IV gave the corresponding 3-methyl-2-(1H)-quinoxalinones (VI) and benzoic acid (VII), while that of V afforded the starting substances, o-aminophenols (III) and benzoylpyruvic acid (VIII) which had been partially decomposed into pyruvic acid (IX) and VII.
Asymmetric Hydrogenation of C=O Double Bond with Modified Raney Nickel. XX. The Effect of Additives on the Asymmetric Activity
Authors: Higashi Fukuji , Ninomiya Toshio , Izumi Yoshiharu 
Published: July 2006

Abstract
The effects of various additives in methyl acetoacetate were tested in the asymmetric hydrogenation reaction. Among them, water has a particular effect on the asymmetric activities of the catalysts; in the presence of a certain amount of water, the catalysts modified with l-Glu, l-Val, and l-Ala hydrogenated methyl acetoacetate to methyl ls(+)3-hydroxybutyrate, while, without the addition of water, the catalysts promoted the hydrogenation to yield methyl ds(−)3-hydroxybutyrate. The catalyst modified with l-Ala at pH 6.0 and the catalyst modified with l-Glu at pH 5.0 and 100°C were especially sensitive to water, and both catalysts showed (+) asymmetric activity when a trace of water was also present. Even in the hydrogenation without the addition of water, the recovered catalysts modified with l-Glu, l-Val, and l-Ala from the hydrogenation in the presence of water gave results similar to those in the hydrogenation in the presence of water. The effect of water as an additive was discussed, and it was concluded that the water affects the asymmetric site of the catalyst rather than the keto-enol equilibrium of the substrate.
Intramolecular Interaction between Hydroxyl Group and π-Electrons. XXIV. The Interaction Involving the Cyano Group
Authors: Oki Michinori , Yoshida Takashi 
Published: July 2006

Abstract
The infrared O–H stretching spectra of various 1- and 2-cyano alcohols have been measured, and the presence of intramolecular O–H···π interaction has been detected. Some discussion of the confirmation of such alcohols is given.
The Reaction of Ethyl Alkylchloropyruvate with Sodiomalonate and Sodioacetoacetate
Authors: Takeda Akira , Wada Satosi , Fujii Masatosi , Nakasima Isao , Hirata Shoiti 
Published: July 2006

Abstract
The reaction of alkylchloropyruvate (1) with sodiomalonate gave γ-alkyl-α,β-dialkoxycarbonyl-Δβ,γ-butenolide (2), which led to γ-ketocarboxylic acid (3). The reaction of 1 with sodioacetoacetate gave 2-alkyl-5-methylfuran-3,4-dicarboxylate (6) via the intermediate 2-alkyl-3-hydroxy-5-methyl-2,3-dihydrofuran-3,4-dicarboxylate (5). It has been shown unambiguously that the carbanions of both sodiomalonate and sodioacetoacetate attack the carbonyl carbon of 1 predominantly.