bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Infrared Spectra of α-Chlorinated Acetamides
Authors: Mido Yoshiyuki 
Published: July 2006

Abstract
The polarized infrared spectra of α,α,α-trichloroacetamide (TCA) and its deuterated compound (TCA-d) have been measured in the 400–4000 cm−1 region, and the infrared spectra of the series, CClnH3−nCONH2 (n=0–3), and their deuterated compounds have been observed in the solid state. On the basis of the results, the vibrational assignments, the orientation of TCA, the intermolecular hydrogen bonds, and the inductive effect of the introduction of the chlorine atom, and the conformation of TCA have been discussed. It has been proposed that TCA in the solid state has two conformations, which are in linear-chain associations through hydrogen bonds.
Mössbauer Study of the Thermal Decomposition Products of K2FeO4
Authors: Ichida Toshio 
Published: July 2006

Abstract
The thermal decomposition process of a hexavalent iron compound, K2FeO4, was studied by means of the Mössbauer effect. The compound began to decompose in air at about 170°C, and an amorphous product was obtained by the decomposition below 200°C. The product showed a paramagnetic Mössbauer spectrum at 293°K, with an isomer shift and quadrupole splitting of +0.40±0.02 mm/sec and 0.64±0.02 mm/sec respectively; it also showed a magnetically-split six-line spectrum at 4.2°K, with an internal magnetic field of 480±5 kOe. These Mössbauer parameters are characteristic of the Fe3+ state. The intermediate valence states, Fe5+ or Fe4+, were not observed during the decomposition process, and so it was concluded that the Fe6+ ions in K2FeO4 were reduced directly to Fe3+ ions. KFeO2 was formed in air above 250°C, and the temperature dependence of the internal magnetic field showed the Néel temperature of KFeO2 to be very high, 983±10°K.
Light Scattering Studies on the Thermal Denaturation of Bovine Serum Albumin
Authors: Nakagaki Masayuki , Sano Yoh 
Published: July 2006

Abstract
Thermal denaturation of bovine serum albumin (BSA) was studied by means of light scattering and viscosity measurements. The degree of denaturation (wD°) was measured by using HABA, an anionic dye. The values of intrinsic viscosity, weight-average molecular weight and radius of gyration showed no appreciable changes when wD° was within 85 percent, but increased remarkably when wD° exceeded 85 percent. Thus, it has been concluded that the thermal denaturation proceeds in two steps, i.e., intramolecular denaturation in the earlier stage and intermolecular association in the later stage. Analysis of the light-scattering data showed that the aggregated molecule was in a rod-like shape, whose length increased almost linearly with the weight fraction of the aggregated molecule wn, the latter being obtained by analysis of the refractive index increment. On the other hand, the diameter did not change with the degree of denaturation, and its value was about 140 Å, which is almost equal to the largest dimension of the native BSA molecule. It has been concluded that the BSA molecules form aggregates by side-by-side association, whose length is about 2910 Å and diameter about 140 Å.
The Molecular Vibrations and the Rotational Isomerism of (Chloromethyl)methylsilane
Authors: Hayashi Michiro , Ohno Keiichi , Murata Hiromu 
Published: July 2006

Abstract
The infrared spectra of (chloromethyl)methylsilane and its deuterated species have been measured in the gaseous, liquid, and crystalline states. The normal vibration calculation has been carried out using a modified Urey-Bradley force field. It has been concluded that, in the gaseous and liquid states, there exist both the trans and gauche isomers, while only the former persists in the crystalline state. For ClCH2SiD2CH3, a different spectral pattern has sometimes been recorded in the crystalline state before the sample has been annealed enough. It has been concluded that the persisting isomer is in the gauche form in this metastable crystalline state. The trans and gauche isomers have been found, from the temperature dependence of the relative intensities of the spectra, to have nearly the same energy in the liquid state. From the solvent effects of the spectra, the trans isomer has been found to be more polar than the gauche isomer. Therefore, if the C–Cl bond moment is assumed to have the direction of C+–Cl−, the group moment of the C2SiH2 part of the molecule must be in the direction of (Remark: Graphics omitted.) on the bisector of the C–Si–C angle. The vibrational assignments have been worked out taking into account the results of the normal vibration calculations and the reported assignments for chloromethylsilane, dimethylsilane, and ethylmethylsilane.
The Crystal and Molecular Structure of p-Hydroxybenzoic Acid Monohydrate
Authors: Fukuyama Keiichi , Ohkura Kenji , Kashino Setsuo , Haisa Masao 
Published: July 2006

Abstract
The crystal and molecular structure of p-hydroxybenzoic acid monohydrate has been determined by a single crystal X-ray analysis. The crystals are monoclinic, space group P21⁄a, Z=4, with a=17.79, b=6.39, c=6.79 Å, and β=105.6°. The structure was solved by the Patterson and Fourier methods, and refined by the block-diagonal least-squares method to a final R value of 0.086 for 806 non-zero reflections. Pairs of acid molecules form dimers by the hydrogen bonds between carboxyl groups (2.678 Å). The dimers are held together by the hydrogen bonds between phenolic hydroxyl groups and water molecules (2.595 and 2.823 Å); these hydrogen bonds extend around two-fold screw axes to make up layers of the dimers parallel to the (401). The layers are linked by the additional hydrogen bonds between carbonyl oxygens and water molecules (2.823 Å).
Effect of Halogens on the Ionization of Alkali Metals in the Hydrogen Flame Ionization Detector for Ultra-Micro Analysis of Alkali and Alkaline Earth Metals
Authors: Yamada Masaaki , Suzuki Shigetaka , Araki Shun 
Published: July 2006

Abstract
Quantitative treatment of alkali metals in a small hydrogen flame in the presence or absence of halogens was studied. The proportionality of the ion current to the concentration of alkali metals was found to depend on the applied potential of the electrodes. On adding halogens, the concentration of free neutral alkali atoms decreased. Addition of bromine and iodine increased the ionization of alkali metals, while fluorine decreased it slightly. Addition of chlorine increased or decreased the ionization. The thermionic detection mechanism of halogen-containing compounds in TID of gas chromatograph was discussed.
Estimation of the Thermal Yields in the Reaction with Methanes of 80Br Activated by (n, γ) Process
Authors: Saeki Masakatsu , Tachikawa Enzo 
Published: July 2006

Abstract
The Estrup-Wolfgang Kinetic theory has been applied to the results obtained from the reactions of 80Br activated by the (n,γ) process with two methanes, CH4 and CD4. With suitable assumptions, the most probable kinetic parameters, I’s and α’s have been obtained. The thermal yields of the products have been estimated as a function of the m.f. of the Kr moderator as the differences between the yields predicted by the kinetic theory with these kinetic parameters and those experimentally obtained. The thermal CH380Br and CD380Br yields are strongly affected by the m.f. of Kr in such a way that they are not important in the range from zero to around 0.7 m.f. of Kr, but become significant over 0.7 m.f. of Kr. On the other hand, the thermal CH280BrBr and CD280BrBr yields are much less sensitive to the m.f. of Kr and are almost constant at 0.5% over the whole moderator range of Kr.
The Crystal and Molecular Structure of Vitamin B6 Derivatives. I. Pyridoxal Phosphate Hydrate and Pyridoxal Phosphate Methyl Hemiacetal
Authors: Fujiwara Takaji 
Published: July 2006

Abstract
Pyridoxal phosphate hydrate (PLPHYD) was crystallized from an aqueous solution in the form of monoclinic needles; space group P21⁄c with a=10.503, b=13.608, c=7.488 Å, β=93.71° and four molecules in the unit cell. Prism-shaped crystal of pyridoxal phosphate methyl hemiacetal (PLPMHA) was obtained by dissolving the pyridoxal phosphate hydrate crystals into 90% methanol; space group P\barl, with cell dimensions, a=9.42, b=10.61, c=6.20 Å, α=105.6°, β=95.7°, and γ=99.7°, and two molecules per cell. Intensity data were collected on an automated diffractometer for PLPHYD and photographically for PLPMHA. Crystal structures have been determined by the symbolic addition method. Refinements were done by the block-diagonal least-squares procedures, the final R value being 0.093 for PLPHYD and 0.112 for PLPMHA. The free aldehyde group of pyridoxal phosphate interacts with water molecule to form gem-diol in the crystalline state of PLPHYD and the gem-diol group of PLPHYD with methanol to form methyl hemiacetal. One of the two hydrogen atoms on a phosphate group is liberated and protonated to the pyridine ring nitrogen atom, resulting in the zwitterionic structure for both PLPHYD and PLPMHA molecules. All hydrogen bonds in PLPHYD are intermolecular ones, but in PLPMHA there is one OH–O intramolecular hydrogen bond.
The Dimerization of Acrylonitrile to 2-Methyleneglutaronitrile with Metal Halide and Trialkylamine
Authors: Watanabe Yoshihisa , Takeda Makoto 
Published: July 2006

Abstract
Acrylonitrile is dimerized to 2-methyleneglutaronitrile by the binary catalyst system of metal halide and trialkylamine. The catalytic activities of metals are in this order: Co(II)≥Zn(II)&gt;&gt;Fe(II)&gt;Al(III)&gt;&gt;V(III)&gt;Cd(II)&gt;Ti(IV), while that of halogens is I&gt;Br&gt;Cl. Triethylamine is particularly effective for the reaction. The kinetic features are discussed, and a reaction mechanism for the catalyst system of zinc chloride and triethylamine is proposed.
Oxidation of Diphosphine Dioxides, Disulfides and Phosphinothioite and Photolysis of Diphosphine Disulfides. Formation of Phosphinic and Phosphinothioic Anhydrides
Authors: Emoto Tateki , Okazaki Renji , Inamoto Naoki 
Published: July 2006

Abstract
Oxidation of tetraphenyldiphosphine dioxide with an equimolar amount of peroxybenzoic acid (III) gave diphenylphosphinic anhydride in a good yield. Similarly, diphosphine disulfides (II) with 1.5–2.0 mol times of III, gave the corresponding phosphinothioic anhydrides (V), together with the corresponding phosphinic acid and sulfur. II gave V in air in refluxing xylene or o-dichlorobenzene. The yields of V increased with reaction temperature and with reaction time, indicating a homolytic fission of the P(S)–P(S) bond. Reaction of tetraphenyldiphosphine disulfide with sulfur in refluxing o-dichlorobenzene gave bis(diphenylphosphinothioyl) sulfide. Photolysis of II with a low pressure mercury lamp gave phosphinic acid and sulfur under oxygen, and gave phosphine sulfide and O-methyl phosphinothioate in methanol. Phenyl diphenylphosphinothioite gave diphenyl disulfide and diphenylphosphinic acid with silver nitrate.
Optically Active 9,10-Dihydro-9,10-etheno and -ethanoanthracenes. I. Syntheses of Optically Active 1,5-Disubstituted-9,10-dihydro-9,10-etheno and -ethanoanthracenes.
Authors: Tatemitsu Hitoshi , Ogura Fumio , Nakagawa Masazumi 
Published: July 2006

Abstract
1,5-Dimethoxycarbonyl-9,10-dihydro-9,10-ethenoanthracene was synthesized by the reaction of 1,5-dimethoxycarbonylanthracene with dichloroethylene followed by dechlorination with zinc-copper couple. Optical resolution of l,5-dicarboxy-9,10-dihydro-9,10-ethenoanthracene prepared from the dimethyl ester could be achieved by strychnine to give optically pure (−)-dicarboxylic acid and (+)-diacid with an optical purity of 87.3%. Catalytic reduction of (−)-dicarboxylic acid afforded (−)-ethano-dicarboxylic acid. Transformation of the carboxyl groups in various substituent groups to give optically active C2-symmetrical etheno- and ethanoanthracene derivatives belonging to the same series of absolute configuration as that of the starting material is described.
Stereochemical Studies on the Halogenation of Sulfoxides. II. The Bromination of Cyclic Sulfoxides
Authors: Iriuchijima Shinobu , Tsuchihashi Gen-ichi 
Published: July 2006

Abstract
The cyclic sulfoxides, thiane 1-oxide, 4-chlorothiane 1-oxides, and 4-phenylthiane 1-oxides, were brominated with a mixture of bromine and N-bromosuccinimide in the presence of pyridine. The stereoformulas of the products, together with those of the isomers with an inverted sulfoxide configuration, were determined by means of the IR and NMR spectral data and by a comparison of the Rf-values in the tic. As a result, it has been revealed that the bromination reaction gives products in which a bromine atom is introduced stereospecifically at a trans-position to the sulfinyl lone pair, in a manner similar to that of the chlorination reaction reported previously. The same mechanism as in the chlorination is proposed for the main reaction course.
The Structures of the Reoxidation Products of 7,8-Dihydroneopterin
Authors: Sugiura Katsura , Goto Miki 
Published: July 2006

Abstract
On the reduction of d-erythro-neopterin with sodium dithionite, after which it was let stand in neutral pH, three colorless compounds, I, II, and III, and two yellow compounds, I and II, were obtained. On the reduction of d-erythro-neopterin with Fe dust in 25% acetic acid, after which it was let stand at a neutral pH, two yellow compounds, II and III, were obtained. From UV and NMR spectral data as well as from the chemical reactions, the structures for these compounds were identified, Colorless Compound I is 2-amino-4-hydroxy-6-(1′,3′-dihydroxypropyl)pteridine; Colorless Compound II, 2-amino-4-hydroxy-6-(d-erythro-1′,2′,3′-trihydroxypropyl)-pteridine; Colorless Compound III, 2-amino-4-hydroxy-6-(d-threo1′,2′3′-trihydroxypropyl)pteridine; Yellow Compound I, 2-amino-4-hydroxy-6-(1′-oxo-3′-sulfopropyl)-7,8-dihydropteridine; Yellow Compound II, 2-amino-4-hydroxy-6-(1′-oxo-3′-hydroxypropyl)-7,8-dihydropteridine, and Yellow Compound III, 2-amino-4-hydroxy-6-(1′-oxo-2′,3′-dihydroxypropyl)-7,8-dihydropteridine.
Chemical Studies on Tuberactinomycin. V. Structures of Guanidino Amino Acids in Tuberactinomycins
Authors: Wakamiya Tateaki , Shiba Tetsuo , Kaneko Takeo , Sakakibara Hideo , Noda Toshiharu , Take Teruo 
Published: July 2006

Abstract
Tuberactidine (III) is a guanidino amino acid component of an ti tubercular pep tides, tuberactinomycin A and B, while the known guanidino amino acid capreomycidine (V) is involved in tuberactinomycin N and O. The structure of tuberactidine was assigned to be α-(4-hydroxy-2-iminohexahydro-6-pyrimidinyl)glycine and its stereochemistry was also established. During isolation of tuberactidine from an eluate in the column chromatography of tuberactinomycin hydrolyzate, it was converted to Nα-formyltuberactidine dimer (I). In this dimer, structural alternation between a carbinolamine form of cyclol type and an amide lactone form was noticed depending to a pH of the solution. I was hydrolyzed to tuberactidine and viomycidine (IV) with hydrobromic acid. In addition, a plausible pathway for the formation of viocidic acid (VII), one of the artifacts formed during hydrolysis of tuberactinomycin, was proposed.
S
N2 Reactions in Dipolar Aprotic Solvents. III. Chlorine Isotopic Exchange Reactions of Cinnamyl Chlorides and 3-Aryl-2-propynyl Chlorides. Effect of the Unsaturated Group Adjacent to the Reaction Center
Authors: Hayami Jun-ichi , Tanaka Nobuo , Kaji Aritsune 
Published: July 2006

Abstract
Chlorine isotopic exchange reactions of substituted cinnamyl chlorides and 3-aryl-2-propynyl chlorides with tetraethylammonium chloride-36Cl were studied in acetonitrile. In both cases, the electron-donating groups accelerated the reaction. An acceptable linear Hammett relationship was found for the propynyl chlorides. Cinnamyl chlorides gave a linear relationship for the m-substituted compounds superposed by a concaved U-shaped relationship of p-substituted compounds. Both classes of compounds showed 102−3 times of rate enhancement, compared with 2-arylethyl chlorides in the similar isotopic exchange reaction. Features of these SN2 reactions are discussed.
Cyclization Reactions of 1,2-Bis(2-cyanophenyl)propionitriles. II. Synthesis of 5-amino-4,7-dimethoxy-11H-indeno-[1,2-c]isoquinolin-11-one
Authors: Ando Kazuo , Tokoroyama Takashi , Kubota Takashi 
Published: July 2006

Abstract
The structure of 5-amino-4,7-dimethoxy-11H-indeno-[1,2-c]isoquinolin-11-one (2) derived by the degradation of the “red pigment” has been confirmed by synthesis. 5,6-Dihydro-4,7-dimethoxy-11H-indeno[1,2-c]isoquinoline-5,11-dione (3) obtained from 2 was used as a relay compound. This was first converted into 2 by chlorination with phosphorus oxychloride and treatment with ammonia. Subsequently 3 was synthesized from 2-(2-carboxy-3-methoxyphenyl)-4-methoxyindane-1,3-dione (13) via 4,7-dimethoxy-11H-indeno[1,2-c]isocoumarin-11-one (12).
Triisopropoxy Boroxine as a Reducing Agent for Substituted Benzaldehydes
Authors: Iida Hirotada , Kitamura Hironori , Seita Ken , Yamada Kazutoshi 
Published: July 2006

Abstract
Substituted benzaldehydes could be reduced to corresponding benzyl alcohols in fairly good yield at 130 °C, using triisopropoxy boroxine as a reducing agent. The rates of the reduction of benzaldehyde with triisopropoxy boroxine were about ten times as large as those with triisopropyl borate at 110–130 °C.
Stereospecific Reductions of Isoilludin S and M on Alumina Chromatography
Authors: Ichihara Akitami , Matsumoto Takeshi 
Published: July 2006

Abstract
Alumina column chromatography with ethanol as solvent converted planar α-ketols, illudin S and illudin M, to the dihydroxy compounds. The stereospecific reduction was discussed mechanistically as one of the Meerwein-Ponndorf-Verley reduction.
Nonideality of Ammonia Solutions in N,N-Dimethylformamide
Authors: Patnaik Rabindranath , Lloyd William G 
Published: July 2006

Abstract
Solutions of ammonia at 0–40 °C and 0.2–1.2 atm in N,N-dimethylformamide exhibit negative deviations from Raoult’s Law and marked departures from Henry’s Law. This behavior is shown to be consistent with predictions of a simple model for solute-solute hydrogen bonding.
Mechanism of High-energy-induced Luminescence of Solid 2,3-Dimethylbutane Containing Toluene at 77 K
Authors: Miyazaki Tetsuo , Fujitani Yoshiteru , Kuri Zen-ichiro 
Published: July 2006

Abstract
The luminescence from 2,3-dimethylbutane (23DMB) containing a small amount of toluene (To) has been observed in the solid phase at 77 K during γ-irradiation or by ns pulse irradiation with X-rays. The emission spectrum from 23DMB–To (2 mol%) during γ-irradiation at 77 K consists of the fluorescence from the singletexcited toluene and the phosphorescence from the triplet-excited toluene. Both the singlet- and triplet-excited toluenes are formed by the energy transfer from the irradiated 23DMB to toluene. When nitrous oxide or propylene is added to the 23DMB–To mixture, the emission spectrum is changed and becomes very similar to that from the 23DMB–To mixture during illumination with UV lights at 77 K. The spectrum, which disappears upon the addition of nitrous oxide or propylene, consists mainly of phosphorescence. It is concluded that the triplet-excited toluene may be formed by the migration of a hole and an electron. The effects of electron scavengers, such as nitrous oxide and carbon dioxide, or hole scavengers, such as propylene or tetramethylethylene, on the fluorescence have been studied by nsec-pulse irradiation. Since the fluorescence is not appreciably affected by the addition of these scavengers, the singlet-excited toluene may be formed by the excitation transfer.
Mechanisms of Hydrogenation and Hydrogen Exchange of Propylene over the Electron Donor-Acceptor Complexes of Polynaphthoquinones with Potassium
Authors: Iwasawa Yasuhiro , Ogasawara Sadao , Onishi Takaharu , Tamaru Kenzi 
Published: July 2006

Abstract
The mechanisms of the deuterium addition to propylene and the propylene-deuterium exchange reaction over the electron donor-acceptor (EDA) complex of polynaphthoquinone with potassium were investigated by means of mass and microwave spectrometry and gas chromatography in the range from room temperature to 200°C. The hydrogenation as well as the exchange reaction proceeded via the half-hydrogenated state of propylene formed from the adsorbed propylene and the dissociatively-adsorbed deuterium atom on the EDA complex. However, the rate of the exchange reaction decreased upon the Fe addition to the complex, while the hydrogenation was markedly accelerated. The intermediate of the propylene-deuterium exchange reaction was determined to be the half-hydrogenated isopropyl species, whereas the deuterium addition to propylene was suggested to occur via another half-hydrogenated state, the n-propyl species.
The Optically-active Vibration and Elastic Constant of Soda-niter
Authors: Yamamoto Akio , Shiro Yuji , Murata Hiromu 
Published: July 2006

Abstract
A force field which reproduces satisfactorily both the observed vibrational frequencies and the elastic constants has been determined for the sodium nitrate crystal using the short-range interaction model. In addition to the short-range interactions, the long-range interactions of the vibrationally-induced dipoles were also taken into consideration on the basis of the rigid-ion model; those effective charges which explain fairly well the observed TO–LO frequency splittings were obtained. The distribution of the effective charges on each atom was examined; the best set of effective charges has been found to be ZNa=0.87e, ZN=0.17e, and Zo=−0.35e.
Polarographic Studies of Some Metal (II)-Thiocyanate Complexes in Acetonitrile
Authors: Misumi Seizo , Aihara Makoto , Kinoshita Setsuko 
Published: July 2006

Abstract
The formation of thiocyanate complexes of cadmium (II), copper(II), cobalt(II), and iron(II) has been studied in acetonitrile by polarographic, conductometric, and spectrophotometric methods. The values of overall stability constants were found to be; logβ4=19.7 for [Cd(SCN)4]2−, logβ2=7.6 for [Cu(SCN)2]− and logβ4=15.5 for [Co(NCS)4]2−. The reaction between copper(II) species and mercury metal was investigated and the electrode reaction was estimated. Kinetic current for cobalt(II)-thiocyanate complex was observed and the rate constant for the dissociation of the complex was obtained. The rate constant of reduction in the iron(II)-thiocyanate system was determined to be 1.9×10−3 cm/s by cyclic voltammetry.
Effects of Substituents on pKa and τOH Values of Hydroxyaryl-1,3,5-triazines; σP− Values of 1,3,5-Triazinyl Groups.
Authors: Ohto Yukio , Hashida Y\={o}ji , Sekiguchi Shizen , Matsui Kohji 
Published: July 2006

Abstract
Regular relations were found between substituents in the s-triazine nucleus and pKa values, τOH values of o- and p-hydroxyphenyl-s-triazines, and stabilities of chelation of the o-isomers. The substituent constants (σp−) for some s-triazinyl groups were also found.
The Diffusion of Gases at High Pressures. V. The Diffusion of CTH3 in the CO2–Ar System
Authors: Takahashi Shinji 
Published: July 2006

Abstract
The diffusion coefficients of radioactive methane (CTH3) in argon and in mixtures of carbon dioxide with argon(0.719, 0.497, and 0.245 mol fractions of aigon) were measured at the temperatures of 25, 50, and 75°C in the 15∼250 atm pressure range. The measurements were made through a plug of porous bronze in the diffusion cell by using the radioactive tracer technique. The diffusion coefficient-density products, Dρ, for the CTH3–argon system increased slightly with the density in the region below 5 mol/1, and decreased slightly in the region above 5 mol/1. The Dρ for the CTH3–mixture systems decreased slightly with the density over the whole range studied here. The density dependence of Dρ-values at high densities could not be predicted by Enskog-Thorne’s theory.