bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chlorofluorination of Carbon Disulfide and Sulfur
Authors: Abe Takashi , Nagase Shunji , Kodaira Kazuo , Baba Hajime 
Published: July 2006

Abstract
Chlorofluoromethanes and sulfur hexafluoride were obtained in good yields by the electrochemical fluorination of carbon disulfide in the presence of chlorine. The yields and compositions of the products were altered by the amount of chlorine fed in during electrolysis and also by the concentration of sulfur or carbon tetrachloride dissolved in carbon disulfide. Tetrafluoromethane, trifluoromethylsulfur pentafluoride, difluoromethylene bis-(sulfur pentafluoride), bistrifluoromethyl disulfide, and chlorodifluoromethylsulfur pentafluoride were also among the products. Further, the electrochemical fluorination of elementary sulfur was accomplished by the application of the technique of chlorofluorination, and sulfur hexafluoride was obtained in a reasonable yield. The chlorofluorinations of methyl sulfide and methyl disulfide were also attempted, but they afforded only chlorotrifluoromethane in poor yields.
On the Mechanism of the Vinyl Transetherification Reaction Catalyzed by Mercuric Acetate
Authors: Yuki Heimei , Hatada Koichi , Nagata Kazuhiko 
Published: July 2006

Abstract
The vinyl interchange reaction of methyl vinyl ether and methanol, methanol-d4, or ethanol catalyzed by mercuric acetate has been studied. Some organomercuric compounds have been isolated from the reaction mixture, and their catalytic activity for the interchange reaction has been examined. From these results, the mechanism proposed by Watanabe and Conlon (J. Amer. Chem. Soc., 79, 2828 (1957)) has been confirmed and further details of the reaction mechanism are discussed.
Reactions of Haloferrocenes. II. Kinetic Studies of the Reaction of Haloferrocene with Copper (I) Chloride - Pyridine Complex
Authors: Sato Masaru , Motoyama Izumi , Hata Kazuo 
Published: July 2006

Abstract
The reaction of bromoferrocene with copper(I) chloride - pyridine complex was found to be second-order, that is, first-order in each of bromoferrocene and copper(I) chloride-pyridine complex. The results obtained from the competitive reactions between bromoferrocene and bromobenzene indicated that bromoferrocene was 103 times more reactive than bromobenzene in the halogen-exchange reaction. The effects of the pyridine bases on the halogen-exchange reaction of bromoferrocene were examined, and the trend of the results was found to be different from that of bromobenzene. The reason for this was discussed on the basis of the reaction mechanism.
Tri(hetero)substituted Carbonium Ions. II. 2-Dialkylamino-1,3-dithiolanylium Ions. Reactions with Nucleophiles and Ambident Behaviors
Authors: Nakai Takeshi , Okawara Makoto 
Published: July 2006

Abstract
The reactions of 2-dialkylamino-1,3-dithiolanylium perchlorates with a variety of nucleophilic species including oxygen, sulfur and nitrogen nucleophiles have been investigated. Examination of the isolated products reveals that these trihetrosubstituted carbonium ions behave as ambident electrophiles toward nucleophiles with two reactive sites, i.e., the electron-deficient centered carbon (a) and the ring-methylene carbon atom (b), and that the nature of nucleophiles greatly affects the reaction course in a straightforward manner. The reaction course may be classified as follows. If the nucleophile is basic, the reaction at the site (a) (mode A) is favored, but if it has large sub-stituents, the initial proton abstraction reaction (mode C) is predominant, while if the nucleophile is polarizable, the reaction at the site (b) (mode B) is favored. The major factor deciding the reaction course is discussed in terms of the schematic energy profile of the overall reaction.
Synthetic Studies on Bacitracin. VII. Isomerization of Amino Acid Components of Thiazoline Peptides
Authors: Hirotsu Yoshihiro , Shiba Tetsuo , Kaneko Takeo 
Published: July 2006

Abstract
Ethyl 2-(1-benzyloxycarbonylaminoethyl)-R-Δ2-thiazoline-4-carboxylate (III), ethyl 2-(1-benzyloxycarbonylamino-2-methyl-n-butyl)-R-Δ2-thiazoline-4-carboxylate (VI) and their acid amide derivatives (V, VII and VIII) were prepared by either the iminoether coupling method or the dehydration method. As a general character of thiazoline peptide, it was found that the amino acid residue connected to thiazoline ring at N-terminal side is completely racemized at the stage of thiazoline ring formation, and further epimerized, in the case of isoleucine, by treatment with the basic reagent.
The Molecular Structure of Tin Tetrachloride as Determined by Gas-electron Diffraction
Authors: Fujii Hideji , Kimura Masao 
Published: July 2006

Abstract
The molecular structure of tin tetrachloride was determined by the sector-microphotometer method of gas-electron diffraction. By taking into account the phase-shift for the Sn-Cl pair, the following results were obtained: the tetrahedral structure with rg(Sn–Cl)=2.2808±0.0037 Å, l(Sn–Cl)=0.0499±0.0033 Å, and l(Cl···Cl)=0.1086±0.0050 Å. These values, especially that of the mean amplitude, l(Sn–Cl), are different from those previously reported by other workers. This is because the effect of the phase shift was neglected in the previous investigations.
Variational Calculation of Atoms and Molecules by a Modified Hassé Method Using Hulthén Functions. I. Hydrogen and Helium Atoms
Authors: Yamabe Tokio , Ishimaru Shingo , Fukui Kenichi 
Published: July 2006

Abstract
A modification of the Hassé method is presented in an attempt to describe perturbed systems. This method resolves divergence difficulties which are often encountered when the simple Kirkwood-Hassé method or Unsöld approximation is used for the coulombic perturbation problems. The procedure is illustrated for the perturbed hydrogen atom; energy values which are close to the exact ones are thus obtained. The method is also applied to the case of the ground-state helium atom; a closed-form expression of the energy is thus derived. The optimized value is −2.8983 a. u. Some other discussions are given in connection with the perturbation theory.
Oxidation of Vanadium(II) by Nitrate Ion
Authors: Tanaka Kazuyoshi 
Published: July 2006

Abstract
The oxidation rates of vanadium(II) to vanadium(III) by nitrate ion were determined from the time dependence of the polarographic diffusion currents. As supporting electrolytes sodium perchlorate and sodium sulfate were used. The oxidation rates were linearly dependent on hydrogen ion concentration in strongly acidic solutions (pH&lt;2) and independent in weakly acidic solutions (pH&lt;2). Polarographic half-wave potentials, reversibility and diffusion currents indicated that vanadium(II) in sulfate medium formed a sulfato-complex or an ion-paired species which was oxidized faster than V2+ (hydrated) in perchlorate medium. The oxidation in sulfate medium proceeded mainly by a single two-electron oxidation, and further reaction between vanadium(II) and vanadium(IV) yielded a stable dimer of vanadium(III) detected by absorption experiments. The rates measured in various halide solutions, except fluoride, gave almost the same rate constants in perchlorate medium. The gaseous products from nitrate ion were identified as NO and N2O by infrared spectrum measurements. The overall oxidation was proposed;
8V(II)+2NO_3^-+10H^+→8V(III)+N_2O(g)+5H_2O
Pyrolysis-Gas Chromatographic Analysis of Vinylchloride-Vinylacetate Copolymer
Authors: Okumoto Tadaoki , Takeuchi Tsugio , Tsuge Shin 
Published: July 2006

Abstract
Pyrolysis-gas chromatography was applied to rapid and precise determination of vinylchloride-vinylacetate copolymer by use of the yields of acetic acid and of benzene. The separation column was filled with packing of polymer beads (porapak Q) which are free from deterioration by hydrogen chloride evolved during the thermal degradation of copolymers. Relative yields of acetic acid, which originated from the side chains of the polymer and corresponded to vinylacetate content, and of benzene, formed mainly from successive vinylchloride units, were calculated from the relative peak area appearing on the pyrogram by making relative sensitivity correction for the flame ionization detector. By this method the composition of copolymer can be determined using 0.5–2.0 mg of sample with mean absolute deviation 0.5–0.4 wt%, with the yields of acetic acid and of benzene.
Application of the AC Polarographic Method to the Microdetermination of the Sulfide Ion by the Methylene Blue Procedure
Authors: Hasebe Kiyoshi , Kambara Tomihito 
Published: July 2006

Abstract
A new AC polarographic method utilizing the methylene-blue procedure was used for the determination of the sulfide ion. By means of dimethyl-p-phenylenediamine sulfate and iron(III) alum, the sulfide ion is converted quantitatively into methylene blue in the sulfuric-acid milieu. The methylene blue thus formed shows a prominent and reproducible AC peak, which can be suitably utilized for the indirect microdetermination of the sulfide ion. Halide ions interfere with the determination, however.
Reactions of Some Olefins with N-Chlorourea in the Presence of Acetonitrile
Authors: Wada Yasuo , Oda Ryohei 
Published: July 2006

Abstract
A new three-component reaction of N-chlorourea, olefins and acetonitrile is reported. Styrene gives N-(1-ureidoethylidene)-2-choro-1-phenylethylamine, N-(2-chloro-1-phenylethyl)acetamide and 4-phenyl-2-oxazolidone. Addition proceeds in a Markovnikov manner as shown by structural evidence. Cyclohexene gives N-(1-ureiodoethylidene)-2-chlorocyclohexylamine and N-(2-chlorocyclohexyl)acetamide. The stereochemistry of the reaction has been shown to be trans as demonstrated by chemical and physical evidence. Mechanisms for the reaction are proposed.
Application of the Continuous Variation Method to the Conductometric Determination of Formation Constants–Hexamminecobalt(III) Chloride - Sodium Sulfate and Tris(ethylenediamine) cobalt(III) Chloride - Sodium Sulfate Systems
Authors: Katayama Shunzo , Tamamushi Reita 
Published: July 2006

Abstract
The conductance behavior of mixtures was investigated with the following systems in aqueous solutions of various ionic strengths at 25°C; NaCl - KCl, NaCl - NaClO4, NaCl - Na2SO4, [CO-(NH3)6] Cl3 - Na2SO4 and [CO(en)3]Cl3 - Na2SO4. Appreciable deviations of the measured conductivities from additivity were observed in the last two systems involving the cobalt(III) complexes. The deviation was attributed to the ion-pair formation of the complex cations with sulfate ions; the ion-pair formation constants at various ionic strengths were determined by means of computer analysis of the deviation without relying on the Onsager conductance equation. The thermodynamic ion-pair formation constants at 25°C were as follows: logK=3.53 for [CO(NH3)3+·SO42− and logK=3.60 for [CO(NH3]3+·SO42−. The analysis of conductance behavior of mixtures was proved to be a useful method of studying ion-pair formation particularly at relatively high ionic strengths.
Electronic Absorption Spectra and Electronic Structures of Some Würster’s Blue Salts
Authors: Sakata Tadayoshi , Nagakura Saburo 
Published: July 2006

Abstract
Electronic absorption spectra were measured at various temperatures for Würster’s blue iodide, bromide, and chloride. The charge-transfer bands were found to be strongly dependent upon temperature. Concerning the iodide, the temperature dependency can be explained quantitatively, or at least semiquantitatively, by the aid of the linear Ising model in relation to the local ordering of the electron spins of Würster’s blue cation radicals. This model gives the exchange energy of 99±23 cm−1 for the iodide. For the bromide and the chloride, the dimer model was successfully applied to the analysis of the temperature dependence of the charge-transfer bands, giving singlet-triplet energy separations of 248±30 cm−1 and 255±30 cm−1 for the bromide and the chloride, respectively. The electronic structure and the intermolecular interaction were discussed for these radical salts, their electronic absorption spectra being compared with one another.
Metal Chelates of Some β,δ-Triketone Homologues. Copper(II) Chelates of 2,6-Diacetyl-4-methylphenol, 2,2′-Dihydroxybenzophenone, 2-Acetoacetylphenol and 2-Acetyl-1,8 -dihydroxynaphthalene
Authors: Taguchi Yoshio , Sagara Fumio , Kobayashi Hiroshi , Ueno Keihei 
Published: July 2006

Abstract
Copper(II) chelates of 2,6-diacetyl-4-methylphenol, 2,2′-dihydroxybenzophenone, 2-acetoacetylphenol and 2-acetyl-1,8-dihydroxynaphthalene were synthesized. The first and last ligands give only a mononuclear chelate of type CuL2 respectively, whereas the second and third ones give a binuclear complex of type Cu2L2 in addition to the mononuclear complex. In the cases of the latter ligands two types of complexes are interconvertible and in a solution phase there exists an equilibrium between them. Higher temperature favors a binuclear form and lower temperature another form. Structures of the complexes are assigned with spectroscopic and thermogravimetric data.
Studies of Thin-layer Chromatography of Inorganic Salts. IV. Chromatographic Behavior of Square Planar Complexes in Comparison with that of Octahedral Complexes
Authors: Baba Tetsuo , Yoneda Hayami 
Published: July 2006

Abstract
The chromatography of copper(II) and platinum(II) complexes on silica gel was investigated in comparison with that of cobalt(III) and nickel(II) complexes. Each complex showed various Rf values from zero to unity, when it was developed with aqueous solutions of various salts. This was interpreted to be due to different degrees of anionic association with the complex. The pattern of deversity of Rf values in copper(II) and platinum(II) complexes was found to be definitely different from that in cobalt(III) and nickel(II) complexes. Thus, different association mechanisms were proposed for both cases. In copper(II) and platinum(II) complexes, association occurs through the direct coordination of the anion to the metal ion, while, in cobalt(III) and nickel(II) complexes, association takes place at the outer-sphere of the complex.
The Codimerization of Styrene with Ethylene Catalyzed by Olefin-palladium(II) Chloride Complexes
Authors: Kawamoto Keiji , Imanaka Toshinobu , Teranishi Shiichiro 
Published: July 2006

Abstract
The codimerization of styrene with ethylene catalyzed by the olefin-palladium chloride complexes was investigated in a homogeneous system under mild conditions; di-μ-chloro-dichlorobis-(styrene)dipalladium(II), (Pd(C6H5CH=CH2)Cl2)2, was found to be an effective catalyst. When ethylene was bubbled into a styrene solution containing the styrene-palladium complex at 50°C for 6 hr, codimers including trans-1-phenyl-1-butene, cis-1-phenyl-1-butene, and trans-1-phenyl-2-butene were obtained in 1278, 57 and 170% yields respectively, based on palladium(II) used. However, the absence of ethylene resulted in the formation of a 70% yield of the dimer of styrene, trans-1,3-diphenyl-1-butene. The order of the solvent effect on the rate of the codimerization was as follows: nitrobenzene&gt;nitromethane&gt;acetic acid, phenol&gt;dioxane&gt;&gt;benzene&gt;&gt;acetonitrile. A possible mechanism for this reaction was discussed on the basis of the present results.
Imidazole Catalyses in Aqueous Systems. IV. Bimolecular and Michaelis-Menten-Type Catalyses of a Phenyl Ester Hydrolysis by Some Hydrophobic Imidazole Derivatives
Authors: Kunitake Toyoki , Shinkai Seiji 
Published: July 2006

Abstract
Catalytic hydrolyses of p-acetoxybenzoic acid by several imidazole derivatives were conducted at 15–40°C in aqueous systems using a pH-stat. Imidazole compounds containing the naphthalene ring catalyzed the hydrolysis following the Michaelis-Menten kinetics as in enzymatic reactions, while catalysis by less hydrophobic imidazoles followed the second-order kinetics. Enhancement of the overall catalytic efficiency in the Michaelis-Menten pathway was estimated to be ten times at most as compared with the bimolecular pathway. The thermodynamic and activation parameters were obtained at 15–40°C for the Michaelis-Menten pathway. The binding of catalyst and substrate was characterized by small positive enthalpy changes (ΔH≅+3.5 kcal/ mol) and large positive entropy changes (ΔSu≅+28 eu), indicating that the complex formation was ascribable to hydrophobic interactions. The intra-complex product formation was characterized by not unreasonable ΔH≠ values and extraordinarily large negative ΔS≠ (≅−50 eu) values. The unexpectedly small rate enhancement in the Michaelis-Menten pathway was attributed to the unfavorable ΔS≠ term, which suggested that the structure of the Michaelis complex was quite different from that of the transition state of the product formation.
Kinetic Studies of Adsorbed Films of Tritium-labelled Sodium Stearate at the Air/Water Interface
Authors: Seimiya Tsutomu 
Published: July 2006

Abstract
The adsorption of tritium-labelled sodium stearate at the air/water interface was directly measured radiometrically using an ultra-thin-windowed Geiger-Müller tube for varying soap concentrations, pH values, and temperatures. The changes in the amount of adsorption and in the surface tension were simultaneously traced with the lapse of time. The pressure-area curve was then obtained by the successive plotting of the surface pressure against the area at the same aging; the curve at equilibrium was also obtained. Thus, the pressure-area relationship of the adsorbed monolayer was automatically measured during the course of adsorption approaching equilibrium. A close resemblance was observed between the monolayer of stearic acid on-neutral water and the adsorbed films on the stearate solution of pH values from 8.85 to 9.30 at 30°C. The amount of adsorption measured for an alkaline solution often exceeds the value to be expected from the saturation value for a completely-ionized stearate monolayer. The pressure-area characteristics suggested a transition from the condensed state of the adsorbed film at a higher surface concentration to an expanded state at a lower concentration. It was also confirmed, by measuring the amount of adsorption in the atmospheres of both nitrogen and air containing carbon dioxide, that the atmospheric carbon dioxide acts to increase the adsorption of stearic acid on the aqueous surface. The diffusion coefficient of the adsorbing solute, calculated from the initial rate of adsorption, showed a smaller value than that obtained by conductometric measurements.
Ionic Dissociation. II. An Extended Hückel Treatment of the Dissociation of Pseudo Acids
Authors: Yamabe Hiroko , Kato Hiroshi , Yonezawa Teijiro 
Published: July 2006

Abstract
The electronic structures of several pseudo acids are studied, in connection with their reactivity and stability, by the Extended Hückel method. The linear relationship between the observed pKa value and the change in the calculated electronic energy, ΔE, in the course of the dissociation of the pseudo acids is also observed. The order of the stability of the carbanion, referred to its parent acid, as estimated from our calculations, is; CH2NO2−&gt;CH2COCH3−&gt;CH2CN−. Di- or tri- substituted carbanions should be more stable. This order is parallel with that of the electron-attracting abilities of the groups adjacent to the methylene group. The highest-occupied MO of the carbanion is remarkably unstable, resembling a lone-pair level, and the atomic orbital population of that MO is large at the Pz AO of the carbon. This reflects the high reactivities of the carbanion as a reaction intermediate; the electrophilic addition probably takes place at the carbon atom.
Group Interactions in Polyelectrolytes. III. The Electrostatic Effect of Neighboring Groups on the Ionization of Polyelectrolytes
Authors: Kawabe Hiroshi , Yanagita Masaya 
Published: July 2006

Abstract
The two parameters in the modified Henderson-Hasselbach equation, pH=pKa−n′log-[(1−α)⁄α], where pKa and n′ are empirical constants and where α is a degree of the ionization of a polymeric acid, were evaluated on the assumption that the ionization of polyelectrolytes is electrostatically affected in the main by a few neighboring ionized groups and that the over-all ionization is composed of only a few elementary ionization. The titration curves of various polyelectrolytes in the absence of salt could be classified into two types: ΔpK′≥2 and ΔpK′&lt;2, where ΔpK′ is the difference between the succeeding ionization constants. The maleic acid-styrene copolymer and polyvinyl amine belong to the former type, while polyacrylic acid and pectinic acid belong to the latter. In the former, a plot of pH against log[(1−α)⁄α] nearly falls on a line in only a limited range and n′ is substantially equal to the number of elementary ionizations. In the latter, both pKa and n′ are related to the distance between the groups. The titration curve of polyacrylic acid, drawn by means of the above equation with the parameters calculated on the basis of the kinetic data of the alkaline hydrolysis of polymethyl acrylate, was in good agreement with the observed titration curve. The titration data of other polyelectrolytes also fall nearly on their calculated titration curves.
A Theoretical Consideration of the Electron-scavenging Process in Liquid Hydrocarbons
Authors: Yamazaki Hideo , Shinsaka Kyoji 
Published: July 2006

Abstract
The electron-scavenging process by a scavenger and the random recombination between ions and electrons in a spur in the radiolysis of nonpolar hydrocarbons have been investigated theoretically on the basis of the extended type of Smoluchowski equation. To obtain the approximate solutions, a model of the distribution of charged species in which a positive ion core is surrounded by electrons is assumed; several approximations are also made during the calculation. The reaction rate of the electron scavenging is expressed by the overlapping integral between the concentration of the electrons and that of the scavenger. The rate of the recombination reaction is approximately expressed as the total flux of the electrons flowing into the core of parent ions. The G value of electron scavenging shows a Langmuir-type dependence on the concentration of the electron scavenger. The values of the slope of the sigmoidal curve at the mid point and of the corresponding scavenger concentration almost agree with the experimental value.
Polarography of Halides in Dimethylformamide. V. Bromine and the Tribromide Ion
Authors: Matsui Yoshihisa , Date Yoshio 
Published: July 2006

Abstract
The polarographic behavior of bromine and the tribromide ion at the dropping mercury electrode was investigated in dimethylformamide. A freshly-prepared solution of bromine gives two cathodic waves. When the solution is allowed to stand at 25°C in the dark, however, the first wave gradually becomes anodic, independently of the electrolysis. When the first wave is completely anodic, an equilibrium is established. The resulting polarogram coincides with that of hydrogen tribromide. The formation of hydrogen tribromide was ascribed to the chemical reduction of bromine by dimethylformamide. Diffuse sunlight accelerates the decomposition of bromine, which in turn yields hydrogen bromide. It was also suggested that, when the dropping mercury is used as an indicator electrode, bromine and the tribromide ion may react with the dropping mercury prior to being electrolyzed, forming mercuric bromide and the tribromomercurate ion respectively, which may in turn depolarize the indicator electrode.
The Syntheses and Properties of the Benzothiazole or Benzimidazole Derivative Adducts of Tin(II, IV) and Antimony(III) Halides
Authors: Ouchi Akira , Takeuchi Toshio , Taminaga Iwao 
Published: July 2006

Abstract
The benzothiazole, 2-amino-benzothiazole, benzimidazole-2-thiol, and benzothiazole-2-thiol adducts of tin(II, IV) chlorides, antimony(III) chloride, and antimony (III) bromide with the formulae of Mn+LmXn− (where L is the ligand and where X is Cl or Br) were synthesized. From their electronic and infrared spectra, it can be seen that the 2-amino-benzothiazole adducts are more stable than those of other ligands and that the metal-ligand bonds in the former remain, even in the ethanolic solution.