bluuebunny/crossref_metadata_2025_split huggingface dataset:
Magnetic Susceptibilities of Crystalline Phenothiazine, N-Methylphenothiazine and Thianthrene Radical Salts with Antimony Pentachloride
Authors: Sato Yoichiro , Kinoshita Minoru , Sano Mizuka , Akamatu Hideo 
Published: July 2006

Abstract
Phenothiazine, N-methylphenothiazine and thianthrene are oxidized with antimony pentachloride, and give the corresponding monopositive ion radicals. These aromatic positive ions form crystalline salts with the complex negative ion of antimony pentachloride or tetrachloride. The paramagnetism for these salts is attributed to the aromatic ion radicals, and follows the Curie-Weiss law at higher temperatures, and deviates from it at lower temperatures. This behavior has been interpreted by assuming the linear chain model being applicable, which suggests a remarkable spin exchange interaction in the crystalline salt of phenothiazine·SbCl4, of J/k∼395°K.
Dependence of the Crosslinking Efficiency on the Reaction Conditions in the Peroxide Crosslinking of Unsaturated Polyolefins
Authors: Ashikari Nobuyuki , Kawashima Izumi , Kawashima Takehisa 
Published: July 2006

Abstract
The crosslinking reactions of several unsaturated polyolefins with organic peroxides were carried out in an attempt to establish the dependence of the crosslinking efficiency on the reaction conditions, especially the reaction temperature and the peroxide concentration. Usually, the efficiency gradually increased up to a certain temperature and then decreased abruptly. This efficiency decrease can be considered to be due to (1) a decrease in the hydrogen abstraction, which is one reaction producing crosslinks, and (2) an increase in the termination rate in a chain reaction arising from opening up the double bond, which is another reaction producing crosslinks. Except for cases in which an extremely high temperature was employed or when a very high concentration of peroxide was used, the efficiency decrease by scission reaction upon an elevation of the temperature seems to be comparatively small.
Solvent Effects in the Electron Spin Resonance Spectra of Some Phenoxyl, Nitroxide, and Anilino Radicals
Authors: Mukai Kazuo , Nishiguchi Hiroaki , Ishizu Kazuhiko , Deguchi Yasuo , Takaki Hideo 
Published: July 2006

Abstract
The electron spin resonance spectra of 2,6-di-t-butyl-4-methylphenoxyl (I) and 2,4,6-tri-t butylphenoxyl (II) have been observed under high resolution, and it has been shown experimentally that the para methyl proton hyperfine splitting (aCH3H) in the radical (I) increases, while, inversely, the meta proton hyperfine interaction decreases, as the dipole moment of the solvent (μ) increases. The relationship between these two variables can be written as:
a(μsolv)=a(μsolv=0)+K·μsolv,
where μsolv is the dipole moment of the solvent and where K is the constant of proportionality. Further study of diphenyl nitric oxide (DPNO) (IV) and di-p-anisyl nitric oxide (DPANO) (V) radicals has shown this to be a general form of the solvent effect. However, in the case of various kinds of solvents with OH or NH groups, it has been found that aN deviates from the equation. This phenomenon has been explained qualitatively by the effect of hydrogen bonding. Therefore, the variation in the coupling constants has generally been explained by two effects, that is, the μ dependence described above and the electron delocalization arising from hydrogen bonding. Similar experiments performed with 2,4,6-tri-t-butylphenoxy (II) and 2,4,6-tri-t-butylanilino (III) radicals have shown that the variation in the hyperfine splitting constants is small because of the steric hindrance of tertiary butyl groups in these molecules.
Unusual Behaviors in Electrical Conductivity of Phenanthrene Crystal
Authors: Matsumoto Shoichi 
Published: July 2006

Abstract
Two kinds of unusual behavior in the temperature dependence of electrical conductivity has been observed. One is the anomaly that the resistance begins to increase remarkably with the rise in the temperature around 64°C; the other is a bending-phenomenon in the linear temperature-dependence of the resistance about 54°C. The observed activation energies for conduction are 3.0–3.3 eV below and 4.5–4.8 eV above the anomaly, the energies of which are almost compatible with the intrinsic band-gap energies for conduction, 3.5 and 4.6 eV, estimated, respectively, from the optical absorption and from the values of the ionization potential and the electron affinity. As for below the bending-phenomenon, the observed activation energy is 1.4–1.6 eV, which is quite small compared with the intrinsic band-gap energies estimated. The anomaly beginning around 64°C is interpreted as due to the crystal-phase transition of a higher-order at 60–70°C; the remarkable increase in resistance may be connected with the changes in the intermolecular interaction in the crystal due to the rearrangement of molecules caused by the phase transition. The bending-phenomenon at about 54°C seems to be attributable to an impurity-effect by oxygen.
Crystal Structure of Dichlorobis(cyclohexanone oxime)palladium
Authors: Tanimura Masamitsu , Mizushima Toshio , Kinoshita Yukio 
Published: July 2006

Abstract
The crystal structure of dichlorobis(cyclohexanone oxime)palladium, PdCl2(C6H10NOH)2, has been determined from three-dimensional X-ray photographic data. The crystals belong to the triclinic space group P\bar1, with these cell parameters: a=8.81 Å, b=9.99 Å, c=4.99 Å; α=91°32′, β=99°41′ and γ=102°02′. The unit cell contains one molecule of the complex. The palladium atoms are spaced at intervals of 4.99 Å along the c-axis and have a square planar coordination, with two chlorine atoms at 2.24 Å and two nitrogen atoms of the oxime group at 2.08 Å. The complexes are hydrogen-bonded with each other in strings of indefinite length along the c-axis, and the hydrogen bond distance between the oxygen atom of the hydroxyimino group and the chlorine atom is 2.93 Å.
Electrolyte-Solvent Interaction: Conductance of Lithium Bromide in Acetone-Water Mixtures at Different Temperatures
Authors: Singh D , Mishra Anirudh 
Published: July 2006

Abstract
The conductance of lithium bromide in acetone-water mixtures has been measured at different temperatures (25–40°C) in the dielectric constant range from 17.80 to 61. The association constants and centre-to-centre cation-anion distances have been calculated by a modified Fuoss-Onsager equation applicable to 2&lt;b&lt;15, where b is the Bjerrum parameter. The increase in ion size and the decrease in association constants with the addition of water have been interpreted in terms of the solvated dipoles which contain both solvent molecules in the sheath of solvation. The variation in Walden products and in association constants with the change in the composition of the solvent and the temperature is well represented on this model.
The Mössbauer Spectra of the Iron - Sodium Metaphosphate Systems
Authors: Kamo Mutsukazu , Takashima Yoshimasa , Ohashi Shigeru 
Published: July 2006

Abstract
The Mössbauer spectra of three iron - sodium metaphosphate systems have been studied. The bonding characteristics of the iron atom with the phosphates have been discussed from the results of the Mössbauer spectra. The data for the fused iron oxide - sodium metaphosphate system suggest that the bonding of the iron atom with the phosphates is considerably ionic and the arrangements of metaphosphates in these systems are at random and in a tangle. Some informations on the structure of the Fe2(OH)(PO3)5 system were described.
The Chemistry of Protactinium. V. The Separation of Pa(IV) and Pa(V) by Co-precipitation with Thorium Fluoride
Authors: Mitsuji Toshikazu 
Published: July 2006

Abstract
The separation of Pa(IV) and Pa(V) was investigated using various co-precipitants which were insoluble in acidic solutions. Among them, thorium fluoride was found to be the most useful co-precipitant. The conditions for the separation of both valency states of protactinium were also investigated in detail. This method was applicable to protactinium solutions in the concentration range down to tracer level. It was difficult to reduce Pa(V) completely on a tracer scale by means of a liquid zinc amalgam. When Cr(III) was added to the system, however, the complete reduction of 233Pa(V) was readily attained. The role of Cr(III) was considered to be that Cr(II) formed by liquid-zinc-amalgam reduction mediates the reduction of Pa(V) and protects Pa(IV) from re-oxidation. By this method tetravalent protactinium in a perchloric acid medium was also confirmed to be very stable.
Reaction of 2-Benzimidazolinethione with Dimethylsulfoxide and Acetyl Chloride
Authors: Anzai Kentaro , Suzuki Saburo 
Published: July 2006

Abstract
Dimethyl sulfoxide (DMSO) and acetyl chloride reacted with 2-benzimidazolinethione (I), converting the latter compound to its thiomethoxymethyl and methylenebis derivatives. From the reaction mixture the following compounds were isolated: 1, 3-dithiomethoxymethyl-2-benzimidazolinethione (VII), 1, 1′-methylenebis-3-thiomethoxymethyl-2-benzimidazolinethione (VIII), 1-thiomethoxymethyl-2-benzimidazolinethione (IX), 1, 1′-methylenebis-2-benzimidazolinethione (XIII), and 2-(methylenesulfonium)benzimidazolide (XIV). The mechanism for the formation of these compounds will be discussed. The reaction of 2-benzoxazolinethione (XX) with DMSO and acetyl chloride yielded, besides its thiomethoxymethyl and methylenebis derivatives, 1-hydroxymethylbenzoxazolone (XXIII); the mechanism for the exchange of the sulfur in XX with the oxygen will also be discussed. N-Alkyl derivatives of I could be distinguished from S-alkyl derivatives by their ultraviolet spectra.
The Alkaline Sulfide Reduction of Aromatic Nitro Compounds. XI. The Autocatalytic Reaction of the Monosulfide to the Disulfide in Aqueous Solution
Authors: Hashimoto Shizunobu , Sunamoto Junzo , Sato Katsuhiko 
Published: July 2006

Abstract
The autocatalytic reactions of the aqueous monosulfide to the aqueous disulfide by an ultraviolet light, oxygen, and sodium m-nitrobenzene sulfonate have been investigated. The rate of the disulfide formation by the photo-oxidation of the aqueous monosulfide was given by the following equation: d(S22−)/dt=k0(S2−)2/(S2−)02. Also in the reaction of aromatic nitro compound and aqueous monosulfide, the disulfide formation was observed prior to the amine formation. On the basis of the results obtained, the mechanisms of the alkaline sulfide reduction of aromatic nitro compounds have been discussed.
The Peptide Synthesis. I. Use of the S-Ethylmercapto Group for the Protection of the Thiol Function of Cysteine
Authors: Inukai Noriyoshi , Nakano Kohzi , Murakami Masuo 
Published: July 2006

Abstract
The S-ethylmercapto group was an useful protecting group for the thiol group of cysteine. This group was stable under the conditions of peptide synthesis and was simply split by thiophenol without any side reaction. Glutathione and oxytocin were synthesized using S-ethylmercapto-l-cysteine.
The Reduction of 4-Thiazones and 4-Thiazone-imines, and the Conversion of Triphenyl-4-thiazone to Thiazolium Salts
Authors: Takayanagi Zenichi , Kato Hiroshi , Ohta Masaki 
Published: July 2006

Abstract
The reduction of 4-thiazones and N-acetyl-4-thiazone-imines with sodium borohydride gave thiazolidin-4-ones and 4-acetylaminothiazolidines respectively. Attempts to isomerize 5-alkylidenethiazolidin-4-ones, prepared by the reduction of 5-acyl-4-thiazones, followed by dehydration, to 5-alkyl-4-thiazones were unsuccessful. The ethylation and acetylation of 2, 3, 5-triphenyl-4-thiazone gave the corresponding 4-ethoxy- and 4-acetoxy-thiazolium salts.
Azirines. II. The Reaction of 2-Phenylazirine with Acylating Agents
Authors: Sato Shimao , Kato Hiroshi , Ohta Masaki 
Published: July 2006

Abstract
The reaction of 2-phenylazirine (I) with acid chlorides, anhydrides, an imidoyl chloride, and carboxylic acids were investigated. When I was treated with acid chlorides and anhydrides, the corresponding 2, 5-disubstituted oxazole derivatives were obtained. The reaction of I with phthalic and maleic anhydride, however, gave ring-cleavage products. The reaction of I and N-phenylbenzimidoyl chloride gave 1,2, 5-triphenylimidazole. On the other hand, I and benzoic and thiobenzoic acid gave N-benzoylphenacylamine and N-benzoyl-α-benzoylthio-β-aminostyrene respectively.
Synthetic Studies of Bacitracin. IV. Synthesis of Thiazoline Peptides by Iminoether Coupling Method
Authors: Hirotsu Yoshihiro , Shiba Tetsuo , Kaneko Takeo 
Published: July 2006

Abstract
For the purpose of a total synthesis of bacitracin A, a synthetic method of the thiazoline peptide was investigated. A benzyloxycarbonylaminoalkylimino ethyl ether derived from glycine, l-alanine, l-valine, l-leucine or l-isoleucine was coupled with ethyl l-cysteinate hydrochloride to afford the corresponding thiazoline peptide, that is, a dehydrated form of cysteine peptide. While l-cystine was obtained from acid hydrolyzates of those thiazoline peptides, hydrolysis of them after treatment with alkali or ammonia gave Dl-cystine. Furthermore, alkaline treatment caused a racemization of the amino acid residue adjacent to the thiazoline ring too.
Aminocyclitols. XVI. A Synthesis and Configurational Study of Dibromo-dideoxyinosamine
Authors: Suami Tetsuo , Ogawa Seiichiro , Nakashima Yasuo , Sano Hiroshi 
Published: July 2006

Abstract
Bromination of epi-inosamine-2 in a mixture of acetyl bromide and acetic anhydride afforded 1, 5-dibromo-1, 5-dideoxy-rac-inosamine-6. From this compound, two hitherto unknown inosadiamines: myo-inosadiamine-2, 4 and muco-inosadiamine-2, 3, were obtained by displacement of the bromo groups by azide ions, followed by hydrogenation. The configurations of the new compounds obtained were established by the nuclear magnetic resonance spectra.
Study on Nickel Oxide-Silica-Alumina Catalysts for Ethylene Polymerization. IV. The Structure of the Catalysts Studied by the Oxidation of Carbon Monoxide and by Magnetic Measurements
Authors: Imai Hisao , Uchida Hiroshi 
Published: July 2006

Abstract
The oxidation of carbon monoxide and magnetic susceptibility measurements have been carried out with a series of nickel oxide-silica-alumina catalysts, all of which are the same in aluminum content but which are different in nickel content. The kinetic data of the oxidation followed an Elovich rate equation, and the initial activity per unit of surface area of the catalyst increased as the nickel content increased from 0 to 8.0 atom%. The apparent activation energy was found to be 8±2 kcal/mol. The magnetic susceptibility vs. temperature curves followed the Curie-Weiss relationship in the temperature range between 240 and 723°K, and the effective Bohr magneton number increased to an approximately constant value of 3.7 Bohr magnetons as the nickel content decreased. The structure of the nickel oxide-silica-alumina catalysts has been discussed on the basis of the results obtained, and the Thomas model of the nickel acid site previously proposed for the active site of the ethylene polymerization (H. Uchida and H. Imai, Bull. Chem. Soc. Japan, 35, 995 (1962)) has been confirmed.
The Thermal Decomposition of Metal Oxalato Complexes
Authors: Tanaka Nobuyuki , Nanjo Michio 
Published: July 2006

Abstract
The thermal decomposition of trioxalato complexes of cobalt(III), iron(III) and chromium-(III) has been investigated by the thermogravimetric, the polarographic and the infrared spectroscopic method. The results indicate that, in the case of the iron(III) and the cobalt(III) complexes, the decomposition reaction is initiated by the electron transfer from the coordinated oxalate ion to the central metal ion. In the case of oxalatoamminecobalt(III) complexes, the oxalate ion is considered to be an electron donor; the more oxalate ions are coordinated, the complexes are thermally less stable.
Nucleophilic Reactions of Diethyl N-Phenyliminocarbonate
Authors: Fujisawa Tamotsu , Mukaiyama Teruaki 
Published: July 2006

Abstract
The reactions of diethyl N-phenyliminocarbonate with alkyl halide, acid chloride, lactone, and acid anhydride were studied in order to examine the nucleophilicity of the imino group. These reactions gave the corresponding carbamates at elevated temperatures, much as in the previously reported reactions of iminocarbonates with acids. On the other hand, from the reaction of the iminocarbonate with ethylene carbonate or ethylene sulfite, 3-phenyloxazolidone-2 was obtained along with the evolution of carbon dioxide or sulfur dioxide, respectively.
The Rearrangement of Tropones to Dihydrobenzene Derivatives
Authors: Kikuchi Katsuo 
Published: July 2006

Abstract
The positions of the double bonds in 1-phenylcyclohexadiene-1,2-dicarboxylic acid, which had been obtained previously by the alkaline rearrangement of 2-phenyltropone-7-carboxylic acid, were elucidated from the spectral data. A similar rearrangement of tropone derivatives to dihydrobenzene derivatives was also observed. Tropone-2-carboxylic acid gave 2,5-cyclohexadiene-1,2-dicarboxylic acid, while 2-phenyltropone-5-carboxylic acid afforded 1-phenyl-2,4-cyclohexadiene-1,4-dicarboxylic acid. 2-Phenyltropone was also rearranged by alkali to 2-phenyl-2,5-cyclohexadiene-1-carboxylic acid.
The Solvent Effect on the Rate Ratio of Esterifications of Enantiomeric Menthols with l-Menthoxyacetyl Chloride
Authors: Akiyama Fuminori , Sugino Keiichi , Tokura Niichiro 
Published: July 2006

Abstract
Esterifications of l- and d, l-menthols were undertaked in various solvents, such as chloroform, benzene, n-hexane, acetonitrile, methyl ethyl ketone, and liquid sulfur dioxide, in order to obtain some information on the solvent effect of the resolution of epimers by a kinetical method. The rate ratios, kdl/kll (generally larger than unity except in the case of sulfur dioxide), are in the following order: chloroform, benzene, n-hexane, acetonitrile, methyl ethyl ketone, and liquid sulfur dioxide, indicating higher kdl/kll ratios, in the less specific solvating solvents. The possibility of kinetical resolution in a non-specific solvating solvent is suggested, and the reason for it is discussed.
The Crystal Structure of 1, 6-Dimethoxy Phenazine
Authors: Yaji Hiroshi , Higuchi Taiichi , Shimada Akira , Namba Yoshiyuki , Oda Tsutomu 
Published: July 2006

Abstract
The crystal structure of 1, 6-dimethoxy phenazine was solved by the method of the molecular Fourier transform, and a refinement based on the two-dimensional data was achieved by the Fourier method and also by the least-squares method. The space group is P21/n with two molecules in the unit cell. The lattice constants are a=8.60 Å, b=12.59 Å, c=5.17 Å, and β=93.5°. The molecule has an exact center of symmetry and lies approximately on a plane, with the exception of the methyl groups, which are 0.21 Å outside the plane of the molecule. As for the phenazine ring, almost all the bond distances and angles exhibit normal values. The bond distances around the oxygen atom seem to indicate that the lone-pair electrons in this atom flow into the π-electron system of a phenazine ring. The planar molecules are stacked parallel to each other along the c axis, with an inter-planar spacing of 3.41 Å.
Effect of Molecular Vibrations on Gas Electron Diffraction. II. Probability Distribution Function and Phase Parameter for Polyatomic Molecules
Authors: Kuchitsu Kozo 
Published: July 2006

Abstract
A method has been presented for calculating the first, second, and third moments of the displacement of an internuclear distance in a polyatomic molecule, 〈Δr〉, 〈Δr2〉, and 〈Δr3〉. The moments, which depend on the frequencies of normal vibrations, the cubic potential constants, and the temperature of the system, have been related to the extent of distortion of the probability distribution function of the internuclear distance from a Gaussian function caused by the anharmonicity in the potential function. An approximate expression has been obtained for the phase parameter κ in the molecular intensity of gas electron diffraction in terms of the moments. Numerical results are given for CO2, CS2, SO2, H2O, D2O, CH4, and CD4 by the use of experimental or estimated cubic potential constants. The phase parameters for bonded distances agree with simple estimates based on “diatomic approximation” to the accuracy of current experimental studies, while the phase parameters for nonbonded distances are similar in magnitude to those for bonded distances in spite of their larger mean-square amplitudes of vibration.
Semi-empirical Self-consistent Field Molecular Orbital Calculation of the Electronic Structure of the Base Pairs of Deoxyribonucleic Acid
Authors: Imamura Akira , Fujita Hiroko , Nagata Chikayoshi 
Published: July 2006

Abstract
The electronic structures of adenine-thymine and guanine-cytosine pairs of DNA were calculated using the semi-empirical self-consistent field molecular orbital method. The calculations were carried out for two models, that is, one including hydrogen 2pπ orbitals and the other not. The obtained π electron densities and the π bond orders were then discussed in comparison with those of the corresponding bases. Further, the π electronic stabilization energies due to the hydrogen bond formations were calculated; the π stabilization energy of the G-C pair was found to be larger than that of A-T pair, in agreement with the experimental data. The π electronic structures in the excited states were discussed in connection with the biological behavior of DNA, that is, the misduplication of DNA leading to mutation by irradiation.
The Structures of the Products from the Reaction of 3-Bromotropolone and 7-Bromohinokitiol with Caustic Alkali
Authors: Toda Takashi 
Published: July 2006

Abstract
The main products from the reaction of 3-bromotropolone and 7-bromohinokitiol with caustic alkali are proved not to be 3-hydroxytropolone and 7-hydroxyhinokitiol, but 4-hydroxy-tropolone and 6-hydroxyhinokitiol. The mechanism of this abnormal substitution reaction is then discussed.
Synthesis and Properties of 3-Formyl-1-azaazulan-2-one
Authors: Toda Takashi 
Published: July 2006

Abstract
3-Formyl-1-azaazulan-2-one was synthesized in a good yield from 1-azaazulan-2-one by means of a Vilsmeire reaction and its chemical properties were investigated. The synthesis of the tryptophan analogue from the formyl compound was also attempted.
Proton Magnetic Resonance Spectra of Methyliodothiophenes
Authors: Takahashi Kensuke , Ito Ichi , Matsuki Yasuo 
Published: July 2006

Abstract
PMR data on seventeen compounds, including all of the iodosubstituted derivatives of 2-, 3-methyl and 2, 3-dimethylthiophenes, were given. The signals of β-hydrogens appear at a rather higher applied magnetic field than those of α-hydrogens, while the β-methyl signals appear at a higher field than do the α-methyl signals. The coupling constants between two ring hydrogens, between ring and methyl hydrogens, and between two methyl hydrogens were described.
The Structure of the Free Radical Produced from Carcinogenic 4-Hydroxyaminoquinoline 1-Oxide
Authors: Kataoka Nobuko , Imamura Akira , Kawazoe Yutaka , Chihara Goro , Nagata Chikayoshi 
Published: July 2006

Abstract
A potent carcinogen, 4-hydroxyaminoquinoline 1-oxide, was found to produce a stable free radical oxidatively. The structure of the free radical produced in dioxane was studied by analyizng the hyperfine structure of isotope-substituted 4-hydroxyaminoquinoline 1-oxides, and by comparing the values of the spin densities obtained from the coupling constants with those calculated by the unrestricted SCF MO method. It was concluded that the free radical has the same molecular skeleton as the parent compound, but that it loses a hydrogen atom on the nitrogen atom of the NHOH group.