bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conformation of Adsorbed Polymeric Chain. III
Authors: Motomura Kinsi , Sekita K\={o}j\={u} , Matuura Ryohei 
Published: July 2006

Abstract
Average properties of a copolymeric chain in which a segments of the kind A and b segments of the kind B occur alternatively are calculated for an infinite chain length. For the simplest case of a=b=1, i.e. an alternating copolymeric chain (–A–B–)N, the average number of adsorbed segments of A, \barνA, that of B, \barνB and the mean square end-to-end distance \barr2 are computed numerically as functions of the adsorption energies εA and εB. The values of \barνA, \barνB, and \barr2 are proportional to N for larger values of ηA (=exp(εA⁄kT)) than the critical value (ηA)c at fixed ηB, as found for the case of a homogeneous polymeric chain. It is seen that the behavior of the copolymeric chain near an interface is affected distinctively by the adsorption energies of the segments A and B, and the copolymeric chain is forced to adsorb even for a fairly low adsorption energy of the segment of one kind if the adsorption energy of the segment of the other kind is sufficiently large.
Some Information Derived from the Infrared Spectra of Ionradical Molecules. The Spin-density Distribution for the p-Chloranil Anion Radical
Authors: Iida Yôichi 
Published: July 2006

Abstract
The spin-density distribution in the p-chloranil anion radical was determined by means of the difference in the bond orders of the conjugated systems between p-chloranil and its anion radical, which was estimated on the basis of the stretching force constants. It was found that the spin-density distribution calculated by this method was in good agreement with that estimated by means of the molecular orbital calculations or by means of the hyperfine splitting constants in the ESR absorption. In view of these results, it was suggested that the present method might become a new tool for investigating the unpaired electron distributions of ion-radical molecules in general.
The Adsorption of Water on SiO2, Al2O3, and SiO2·Al2O3. The Relation between the Amounts of Physisorbed and Chemisorbed Water
Authors: Morimoto Tetsuo , Nagao Mahiko , Imai Junichiro 
Published: July 2006

Abstract
The specific surface area, the water content, and the water adsorption isotherm have been measured in order to investigate the interaction between the surfaces of SiO2, Al2O3, and SiO2·Al2O3 and water molecules. Al2O3 gives II-type adsorption isotherms and the amount of adsorbed water on it increases with a rise in the temperature of pretreatment, whereas SiO2 gives isotherms approximate to the III-type and the amount of adsorbed water is larger when treated at lower temperatures. With SiO2·Al2O3, it was found that the type of isotherms and the effect of the pretreatment temperature are similar to those of Al2O3, and that the amount of adsorption increases with an increase in the Al2O3 content. By analysing the adsorption data, the ratio of the amount of physisorbed water in the first layer to the amount of the underlying chemisorbed water was calculated. As a result, it was found that the H2O:OH ratio is 1:2 on the surface of Al2O3, whereas it is 1:1 on the surface of SiO2. The analysis of the isotherms on SiO2·Al2O3 showed that the adsorption property of water on them is not additive: e.g., the amount of adsorbed water on SiO2·Al2O3 is larger than the sum of the water adsorbed on each component. Thus, it has been concluded that, on the surface of SiO2 in contact with Al2O3, the surface hydroxylation proceeds more rapidly than on the surface of pure SiO2.
Electron-Transfer Reactions of Multidentate Ligand Cobalt(III) Complexes. I. The Reductions of Some Chloro(triethylenetetramine)cobalt(III) Complexes by Iron(II)
Authors: Kurimura Yoshimi , Ohashi Kousaburo , Ohtsuki Toshio , Yamamoto Katsumi 
Published: July 2006

Abstract
The kinetics of Fe2+ reductions of cis-α-Co(trien)Cl2+, cis-α-Co(trien)OH2Cl2+ and cis-β1-Co(trien)OH2Cl2+(trien=triethylenetetramine) have been studied at 25°C, [H+]=0.10 m and Σ[ClO4−]=1.0 m. The second-order rate constants obtained are 4.0×10−4 m−1 sec−1, 1.6×10−4 m−1sec−1, and 9.8×10−5 m−1 sec−1 for cis-α-Co(trien)Cl+2, cis-α-Co(trien)OH2Cl2+, and cis-β1-Co(trien)OH2Cl2+ respectively. It is demonstrated, by comparing with other rate data for the Fe2+ reductions of cis-CoN4XCln+ (N=NH3, 0.5 en and 0.25 trien, and X=H2O and Cl−) that the rate decreases with an increase in the number of chelate rings in the Co(III) complexes. The chelate effect of the nonbridging ligand on the electron-transfer reactions of Co(III) complexes is discussed on the basis of a model which involves the ligand-field strength of the trans-ligand to the bridging one, the energy needed for stretching the trans-group away from the Co(III) center, and the effect of the solvation.
The Reaction of Acetylenecarboxylic Acid with Amines. XV. Reaffirmation of the Enamine Structure Facilitated by Intramolecular Hydrogen Bonding Common to the Reaction Products
Authors: Iwanami Yasuo 
Published: July 2006

Abstract
The reactions of dimethyl acetylenedicarboxylate (V) with p-chloroaniline, ethanolamine, ethylenediamine, o-aminophenol, and o-phenylenediamine gave dimethyl N-(p-chlorophenyl)aminofumarate(VI), 3-methoxycarbonylmethylene-3,4,5,6,-tetrahydro-2H-1,4-oxazin-2-one (VII), 3-methoxycarbonylmethylenepiperazin-2-one (VIII), 3-methoxycarbonylmethylene-3,4,-dihydro-2H-1,4-benzoxazine-2-one(IX), and 3-methoxycarbonylmethylene-3,4-dihydro-2(1H)-quinoxalinone(X), respectively. It has been shown that methoxycarbonylmethylene is a common structural element in all products, where the carbonyl is hydrogen-bonded with an amino group to form an enamine form. The spectra measured for crystals (IR) and for solutions in inert solvents (NMR) exhibited the fixation of the enamine form preferentially to the imine form, while NMR spectra for trifluoroacetic acid solutions indicated both forms in equilibrium. Tautomerization occurring in the acid is discussed.
Side-chain Nitrooxylation of Polyalkylbenzenes through Ionic Process
Authors: Nakamura Kiyomi 
Published: July 2006

Abstract
The reaction of polyalkylated aromatic compounds with fuming nitric acid has been investigated with respect to the effects of substituents and added electrolytes on the ease and extent of the concurrent side-chain nitrooxylation and nuclear nitration. Relative reactivity of substituted pentamethylbenzenes C6(CH3)5X for side-chain substitution decreases from 1 to 2×10−2 to 4×10−4 to 3×10−6 with the change of substituent groups from methyl to hydrogen to bromine to nitro in accordance with the ionic character of the reaction. Added electrolytes have profound influence on the reaction rates, but the ratio of products from side chain nitrooxylation and nuclear nitration remains almost unchanged, indicating that both processes share a common intermediate. The relative amount of side-chain substitution depends closely on the positional relationship of alkyl groups in the nucleus, and preferential formation of p-alkylbenzyl nitrates is always observed. It is concluded from the results, that the side-chain nitrooxylation products are formed by way of the polar intermediate common with the ring nitration products. Some plausible reaction sequences are briefly discussed.
Asymmetric Hydrogenation of C=O Double Bond with Modified Raney Nickel. XVIII
Authors: Izumi Yoshiharu , Ohkubo Kazuo 
Published: July 2006

Abstract
The asymmetric activities of the catalysts modified with l-α-amino and l-α-hydroxy acids, which have two asymmetric centers on α, β and α, γ-carbons were studied, and the participation of the β- and γ-configurations to the asymmmetric activity of the catalyst was made clear. It was found that the S:β-configuration and the S:γ-configuration increase the asymmetric activity of the + and − directions respectively.
Conformational Changes in Heterocyclic Analogs of Metaparacyclophane
Authors: Akabori Sadatoshi , Shiomi Kengo , Sato Takeo 
Published: July 2006

Abstract
Sulfur analogs of [2.2]metaparacyclophane, II, III, and IV were prepared and their NMR spectra were examined. Of the three possible inversion mechanism, the one which involves the inversion of the m-phenylene unit is proposed.
Studies on Aminosugars. XXVI. A New Method for the Simultaneous Protection of Amino and Hydroxyl Groups in Aminosugars and Aminocyclitols
Authors: Umezawa Sumio , Takagi Yasushi , Tsuchiya Tsutomu 
Published: July 2006

Abstract
2-Deoxystreptamine-1,6:3,4-dicarbamate (II), methyl 2-amino-2-deoxy-α-d-glucopyranoside-2,3-carbamate (VIII) and methyl 6-amino-6-deoxy-α-d-glucopyranoside-4,6-carbamate (X) were prepared by utilizing p-nitrophenoxycarbonyl chloride or phenoxycarbonyl chloride.
Studies of Peptide Antibiotics. XXIII. Syntheses of Linear Decapeptide Analogs with Gramicidin S Sequence
Authors: Makisumi Satoru , Waki Michinori , Izumiya Nobuo 
Published: July 2006

Abstract
Six linear decapeptides having the same sequence of amino acids of gramicidin S, wherein the N-terminal amino acid is acylated with formyl or acetyl group, the C-terminal amino acid is in a form of its amide or ethanolamide and the N,C-terminal ones are free, were synthesized to obtain a more reliable picture of the cyclic structure to the antibacterial activity of gramicidin S. All these linear decapeptide analogs were found to be active to some extent against several microorganisms.
A Chlorine NQR Study of Trichlorides of Group V Elements
Authors: Hashimoto Masao , Morie Toshiaki , Kato Yoshifumi 
Published: July 2006

Abstract
The NQR frequency of 35Cl has been observed in polycrystalline PCl3, POCl3, AsCl3, and SbCl3 at 77°K and above. In all cases, the resonance frequency decreases at higher temperatures. The temperature coefficient of the resonance frequency is analyzed according to a modified Bayer-type treatment. A qualitative examination of the experimental results, including Robinson’s results for BiCl3 at 83 and 299°K, reveals that the strength of the intermolecular interactions in the solids of these trichlorides decreases in this order: BiCl3&gt;SbCl3&gt;AsCl3&gt;PCl3. The resonance was found to “fade-out” at temperatures below the melting point for the solids of PCl3 and POCl3, while the resonance was observed up to the melting point for the other compounds. The origin of this phenomenon is discussed.
The Catalytic Oxidation of Carbon Monoxide on Titanium Dioxide; Anatase and Rutile
Authors: Onishi Yoshito 
Published: July 2006

Abstract
For the purpose of examining the surface state of titanium dioxide during the catalytic oxidation of carbon monoxide, the electric conductivities of anatase and rutile at 350–800°C, the amount of active oxygen on the catalyst surface at 400–600°C, and oxygen deficiency during the reaction were measured. The temperature-dependence of electric conductivities are represented by the formula σ=A·eE⁄RT in narrow temperature ranges. The amounts of active oxygen per unit surface area of rutile were 3–5 times as much as those of anatase at same temperatures, and 1–3% of them desorbed during the reaction. When the coverage fraction of active oxygen on the catalyst, θ, is assumed to be equal to 1 in oxygen, the following equation can express the relation between the rate constant of the reduction of titanium dioxide by carbon monoxide, kCO, and that of the oxidation of reduced titanium dioxide by oxygen kO2, during the oxidation of carbon monoxide:
k CO·PCO·θ=2kO2·PO2·(1–θ)2.
An Adiabatic Calorimeter for Heat Capacity Measurements in the Temperature Range from 80 to 550 K. Heat Capacities of α-Alumina (Sapphire) and Anhydrous Magnesium Acetate
Authors: Onodera Natsuo , Kimoto Arata , Sakiyama Minoru , Seki Syûzsô 
Published: July 2006

Abstract
An adiabatic calorimeter for the measurements of heat capacities of solid and liquid in the temperature range 80–550 K and the automatic temperature control system are described. The working platinum resistance thermometer is calibrated against a standard thermometer. The measurements of heat capacity of α-Al2O3 prove the precision to be ±0.3% and give an accuracy of ±0.6%. By means of this calorimeter, heat capacities of anhydrous magnesium acetate have been measured for its glassy and crystalline states around the glass transition point.
Studies on s-Triazines. VII. A New Method of Preparing 2-Methyl-4,6-bis(trichloromethyl)-s-triazine
Authors: Wakabayashi Ko , Tsunoda Masaru , Suzuki Yasushi 
Published: July 2006

Abstract
During the liquid-phase chlorination of CH3CN, a trimerization reaction occurred to yield four s-triazine derivatives, 2-methyl-4,6-bis(trichloromethyl)-s-triazine (I), 2-chloromethyl-4,6-bis(trichloromethyl)-s-triazine (II), 2-dichloromethyl-4,6-bis(trichloromethyl)-s-triazine (III), and 2,4,6-tris(trichloromethyl)-s-triazine (IV). The structure of each s-triazine derivative has been assigned on the basis of the results of elemental analysis and the spectral (particularly Mass and NMR) data after each derivative had been separated in a pure form using the gas-liquid chromatographic (GLC) method. The product composition was seen to depend upon the rate of the chrorination of CH3CN and the presence of a catalyst. The s-triazine I was shown to be the precursor of the s-triazines II and III; the pathways for the formation of the s-triazine IV were also investigated. Then, the selective cotrimerization of CH3CN with its chlorinated compounds was investigated; this yielded the s-triazine I, a useful intermediate of pesticides and resines. The reaction was found to provide a new method of preparing s-triazine I.
Measurement of Negative Ions Formed by Electron Impact. VIII. Ionization Efficiency Curves of Negative Ions from Methyl and Ethyl Cyanides
Authors: Tsuda Satoru , Yokohata Akira , Umaba Toshikatsu 
Published: July 2006

Abstract
The ionization efficiency (I.E) curves of m/e 26(CN−), 27(HCN−), 38(C2N−) and 39(CHCN−) ions from methyl and ethyl cyanides, besides 40(CH2CN−) ions from methyl cyanide, and 50(C3N−) ions from ethyl cyanide were measured to the extent of about 25 eV electron energies under the pressure of ∼10−6 mmHg by a Hitachi RMU-6D mass spectrometer. Schemes of plausible reactions expected to appear at each onset value observed in the respective IE curves were sought thermochemically by using ΔHf values of the reactants and products. The estimation method of unknown ΔHf values is described also. It should be noted that for CN− ions one process (probably, R+CN−) was observed in lower energies than 2 eV; C2N− ions are expected to be formed with excess energy; also, for CN− and HCN− ions rather strange phenomena of the decrement of their signal intensities with increasing electron energies were observed in the range of higher energies. Moreover, the IE curves of C3N− ions in the higher energy region were well interpreted in terms of the overlapping phenomena of dissociative capture process with ion pair formation process. It was found from this work that EA(HCN) \gtrsim1 eV, ΔHf(CHCN−) ∼3.2 eV, EA(CHCN) \gtrsim1.1 eV and EA(CH2CN) \gtrsim1.6 eV. For the electron affinity of C2N a value \gtrsim2.3 eV is tentatively introduced on the basis of EA(C3N)=2.4 eV, EA(C5N)=2.3 eV, and EA(CN)=3.4 eV.
Test for Validity of Constant Ionic Medium Principle. Variation of the Activity Coefficient of Hydrogen Ion in Various Compositions of Medium Cations with 3 m Perchlorate Ions
Authors: Ohtaki Hitoshi , Biedermann Georg 
Published: July 2006

Abstract
Potential changes of cells with a glass electrode and a hydrogen electrode in combination with a reference half-cell were measured in solutions of various compositions of cations at constant concentrations of hydrogen and total perchlorate ions. Measurements were carried out for the systems LiClO4-NaClO4, LiClO4-AgClO4, NaClO4-AgClO4, NaClO4-TlClO4, LiClO4-Mg(ClO4)2, LiClO4-Ba(ClO4)2, NaClO4-Ba(ClO4)2, AgClO4-Ba-(ClO4)2, and LiClO4-La(ClO4)3. In some cases a remarkable potential change was observed. Part of the change was due to the variation of the liquid junction potential at the interface of a test solution and a solution in a salt bridge. However, the change was attributed in greater part to the electrostatic free energy change of the transfer of hydrogen ion from a (3/m m Am+, 3m ClO4−) solution to a (xm Am+, ym Bn+, 3m ClO4−) solution (where mx+ny=3). Variation of the composition of electrolytes gives rise to a significant change of the dielectric constant of a solution, so that the activity coefficient of hydrogen ions varies in different solutions at a constant concentration of perchlorate ions. Potential changes are additive in A1(ClO4)m1-B1(ClO4)n1, A1(ClO4)m1-B2(ClO4)n2 and B2(ClO4)n2-B1(ClO4)n1 solutions for a given replacement of cations in solutions, where A1 B1 and B2 denote cations with charges of m1 n1 and n2, respectively.
ESR Measurement and Irradiation at Variable Temperatures below 77°K
Authors: Iwasaki Machio , Nunome Keichi , Ichikawa Takahisa , Toriyama Kazumi 
Published: July 2006

Abstract
An apparatus for irradiation and subsequent ESR measurements at variable temperatures below 77°K was constracted by combining an ESR spectrometer, and an X-ray irradiator, and a laboratory scale low temperature refrigerator operating at the temperature region between 77 and 4.2°K. A device for rotating the single crystal specimen was made to measure the angular dependence of the ESR spectra. The lowest specimen temperature achieved was estimated to be 6°K and the precision of the temperature control was less than ±0.5°K for a period of several hours. The apparatus makes it possible to irradiate samples and to measure ESR spectra at any temperature in the range between 77 and 6°K. Some applications for irradiation and ESR measurements at low temperatures are also described. An unstable radical which disappears at about 60°K was found in an irradiated single crystal of l-cystine dihydrochloride. Experimental evidence for the quantum tunnelling of the methyl group in polymethylmethacrylate radical was also found by the temperature dependence of the spectra observed at temperatures lower than 77°K.
Nature of the Acid Sites on the Surface of Silica-alumina. II. The Relation between the Acid Property of the Sites and the Photo-ionization of Polyacenes Adsorbed on the Surfaces
Authors: Takimoto Kazuto , Miura Masaji 
Published: July 2006

Abstract
The ESR and diffuse reflection spectra of the polyacenes adsorbed on the surfaces of silica gel, alumina, and silica-alumina were measured. The amount of the cation radicals generated on the surfaces was enhanced upon irradiation with UV light. This was interpreted in terms of the photo-ionization accomplished via a chargetransfer state by an absorption of hνCT, which was expected to vary with the strength of the Lewis-acid sites. The rate of the radical formation was not the first order, and that of the annihilation was the second order only in the initial stage. These phenomena are discussed in connection with the heterogeneity of the acid properties on the surfaces.
Spectrophotometric Determination of Benzethonium with Tetrabromophenolphthalein Ethyl Ester
Authors: Tsuboughi Masahiro 
Published: July 2006

Abstract
A spectrophotometric method is proposed for the determination of benzethonium. The method is based on solvent extraction of the ion-pair formed between benzethonium and colored tetrabromophenolphthalein ethyl ester, into 1,2-dichloroethane. The extract has a maximum absorbance at 615 mμ, and follows Beer’s law with good precision up to 4×10−6 m in aqueous solution. The absorbance of the extract is constant in the pH range 7–11. Organic cations interfere.
The Crystal Structure of κ′-Al2O3, the New Intermediate Phase
Authors: Okumiya Masataro , Yamaguchi Goro 
Published: July 2006

Abstract
A structure model of κ′-Al2O3 has been obtained by means of X-ray powder diffraction data. An hexagonal unit cell with a=5.544 and c=9.024 Å and containing 5\frac13 A2O3 was assumed. The oxygen arrangement is the same close packed structure as that of tohdite, and 10\frac23 aluminium atoms are statistically distributed over several octahedral and tetrahedral positions. The R factor for the reflection intensity is 0.13 for 115 reflections.
The Extraction of the Cesium Ion with Some Nitrophenols into Nitrobenzene. I. Distribution Studies
Authors: Koyama Mutsuo , Tochiyama Osamu , Fujinaga Taitiro 
Published: July 2006

Abstract
The liquid-liquid extraction of alkali-metal nitrophenolates was studied by using nitrobenzene as the extracting solvent. Nitrophenol derivatives such as o-, m-, p-nitrophenols, α-dinitrophenol, and picric acid were chosen here in order to examine the effect of their steric characters and pK values on the distribution equilibrid. It was concluded that: 1) all the cesium nitrophenolates extracted into nitrobenzene were mainly in the dissociated form; 2) the extraction of m- and p-nitrophenolates proceeds by the stepwise adduct formation with free phenols, whereas little tendency of adduct formation was observed with the pier ate system; 3) α-dinitrophenolate has a character between the other two; 4) the distribution of o-nitrophenolate is negligible. A detailed discussion is given of the phenomena in terms of ionic equilibria in both the aqueous and organic phases.
Preparation and Circular Dichroism of Six Isomers of Bis(l-alaninate-N-monoacetato)cobaltate(III) Complexes
Authors: Okamoto Ken-ichi , Hidaka Jinsai , Shimura Yoichi 
Published: July 2006

Abstract
Six isomers, two trans(N) and four cis(N), of bis(l-alaninate-N-monoacetato)cobaltate(III) ions have been synthesized as their sodium or potassium salts. The isomers have been separated by ion-exchange column chromatography and their geometrical and chiral configurations determined on the basis of their absorption and circular dichroism spectra in visible and near ultraviolet regions and of proton magnetic resonance spectra. The corresponding l-prolinate-N-monoacetate complex has also been studied. The asymmetry of the coordinated imino nitrogen has been discussed from the analysis of the CD curves.
The Michael Reaction of Fluoro-substituted-9,9′-Bifluorenylidenes and -Fluorenes, and the Syntheses of Some Related Compounds
Authors: Minabe Masahiro , Tanaka Akio , Wakui Masahiro , Suzuki Kazuo 
Published: July 2006

Abstract
The Michael reaction of fluoro-substituted 9,9′-bifluorenylidenes and fluorenes was carried out; the normal addition products, fluoro-substituted tribiphenylenepropanes, were obtained, but no abnormal product was isolated. Some new fluoro-substituted-fluorenes, -9,9′-bifluorenylidenes, -9,9′-bifluorenyls and -α,δ-dibiphenylenebutadienes, were synthesized. The structures of the fluoro-substituted tribiphenylenepropanes were confirmed by the lithium-halogen interconversion reaction of 9-lithiofluorenes and 9-bromo-9,9′-bifluorenyls. The pyrolyses of fluoro-substituted tribiphenylenepropanes afforded fluoro-substituted or nonfluoro-substituted-9,9′-bifluorenylidenes, -9,9′-bifluorenyls, -fluorenes, and -fluorenones. Differential scanning calorimetry was applied to fluoro-substituted-9,9′-bifluorenyls and -tribiphenylenepropanes.
The Hofmann Rearrangement. II. Kinetic Substituent Effects of ortho-, meta-, and para-Substituted N-Chlorobenzamides
Authors: Imamoto Tsuneo , Tsuno Yuho , Yukawa Yasuhide 
Published: July 2006

Abstract
The reaction rates of the Hofmann rearrangement of ortho-, meta-, and para-substituted N-chlorobenzamides were measured under the same reaction conditions as were used for the preceding N-bromo series. The rate constants of the N-chloroamides were found to be slightly larger than those of the N-bromoamides. The relative values of the activation entropy and the activation enthalpy of N-chloro- and N-bromo-derivatives were approximately −4 e.u. and −1.3 kcal/mol respectively. The LFER between the two series was excellent, indicating that the reaction mechanism was almost the same for both series. The effects of the leaving group on the reactivity of ortho-substituents were discussed in terms of the ortho/para rate ratios and the relative values of the activation parameters of ortho- and para-substituents.