bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Performance Characteristics of a Permeation Membrane Device for the Preparation of Dilute Standard Gas Mixtures
Authors: Ibusuki Takashi , Toyokawa Fumitoshi , Imagami Kazunari 
Published: July 2006

Abstract
The performance chracteristics of the permeation membrane device for the preparation of dilute standard gas mixtures developed by us was investigated in detail from the practical standpoint. By selecting a siliconerubber and a TFE Teflon for CO or CH4, and NO or SO2, respectively, the steady permeation state was rapidly attained. The small quantities of the gases permeating through the membranes were precisely determined within a relative standard deviation of 1% based on a pressure-differential method. It was confirmed that the permeation rates were reproducible after repeated membrane-temperature, gas-pressure, and gas-cycle changes during an experimental period of more than five months. By changing the gas pressure and the membrane temperature, and by introducing 1–2 1 min−1 of a diluent gas, N2 or air, standard gas mixtures containing 0.5–10 ppm of CO or CH4 and 0.05–0.7 ppm of NO or SO2 were easily obtained. The standard gases concerning CO, CH4, and NO were compared with those in cylinders prepared by the weighing method, and for SO2 the concentration of the gas was checked by the West-Gaeke method. A good agreement in concentration was observed for CO, CH4, and SO2; the discrepancy found for NO was explained in terms of the decrease in the NO concentration in the cylinder.
A Theoretical Interpretation of the Half-wave Reduction Potentials of Chloronitrobenzenes
Authors: Yamabe Shinichi , Minato Tsutomu , Arai Toshio 
Published: July 2006

Abstract
The half-wave reduction potential of chloronitrobenzenes has been studied with ab initio MO calculations. The relation between the energy of the lowest unoccupied MO and the reduction potential is given.
Vibrational Spectra and Rotational Isomerism of Isopropyl Methyl Selenide and Diisopropyl Selenide
Authors: Ohno Keiichi , Mitsui Akitoshi , Murata Hiromu 
Published: July 2006

Abstract
The infrared and Raman spectra of isopropyl methyl selenide and diisopropyl selenide were measured for the liquid and solid states. The fundamental vibrations were assigned and the rotational isomerism was studied on the basis of the spectral observations and the normal coordinate treatment. For isopropyl methyl selenide, the C1 and Cs forms coexisted in the liquid state and the enthalpy difference between them was obtained as ΔH(C2–Cs)=−0.52×0.05 kcal mol−1. For diisopropyl selenide, it was presumed that only the C2 form persisted in the solid state while the C2, Cs, and C1 forms coexisted in the liquid state, the C2 form being the most stable.
Deuterium Tracer Study on Isomerization of Cyclopropane over Thorium Sulfate
Authors: Imizu Yuzo , Hattori Hideshi , Tanabe Kozo , Kondo Toshihiko 
Published: July 2006

Abstract
Mechanistic study on the isomerization of cyclopropane into propene was made over Th(SO4)2 catalyst. With a fresh catalyst, an induction period was observed, disappearing in successive runs. Coisomerization of cyclopropane d0/d6 reveals that the reaction involves an intermolecular H(or D) transfer. Nearly random location of the H(or D) atom in the mono-exchanged propene-d1, and -d5 indicates that the isomerization proceeds via nonclassical carbonium ion in which seven hydrogen atoms are equivalent.
Determination of Heats of Adsorption of Triphenylchloromethane from Its Hexane Solution onto Dehydrated Silica–Alumina Surface
Authors: Taniguchi Hitofumi , Masuda Tatsuo , Tsutsumi Kazuo , Takahashi Hiroshi 
Published: July 2006

Abstract
Heats of adsorption of gaseous triphenylchloromethane (TPC) onto silica–alumina surface were determined from the heat evolved with the immersion of silica–alumina into TPC–hexane solution. The heat of dissolution and the heat of sublimation of TPC and the heat of immersion of the sample into hexane were considered for their determination. It became clear that TPC molecules interacted with silica–alumina surface in two manners. The one was observed in smaller adsorbed amount (below 45 μmol/g), and the other in adsorbed amount from 45 to 100 μmol/g. The former could be attributed to the interaction between TPC and Lewis or oxidizing sites and the latter to the attractive interaction between the adsorbed molecules. The adsorbed amount in the first stage (4.7×1012 molecules/cm2) agreed closely with the number of Lewis acid sites (5.0×1012 sites/cm2) measured by Leftin and Hall.
Stability of Multi-center Bonds in Inorganic Cluster Compounds
Authors: Aihara Jun-ichi 
Published: July 2006

Abstract
An ideal multi-center bond is a bond in which three or more atomic orbitals of the same kind, each from a different atom, interact equally with each other. Since such a multi-center bond can be regarded as a cyclic conjugated system, the graph theory of aromaticity can be applied to it. It was then found that multi-center bonds are aromatically stabilized to a great extent. Most inorganic cluster compounds are polyhedral in shape. This might be rationalized by the fact that polyhedrons are favorable to a formation of a multi-center bond or the like at the core.
Solvent Effects on Raman Intensity and the Determination of Transition Hyperpolarizability Tensor Element
Authors: Fujiyama Tsunetake , Hatakeyama Haruo , Hyodo Shi-aki 
Published: July 2006

Abstract
Raman intensities of methyl iodide were observed in carbon tetrachloride solution at various concentrations. The observed lines were ν1, ν2, ν3, ν5, and ν6. From the observed data, the transition polarizabilities were determined for the ν1, ν2 and ν3 fundamentals of methyl iodide and the transition hyperpolarizabilities were obtained for the ν3 fundamental of methyl iodide in the form of tensor elements.
On the Critical Phenomena in the Decomposition of Hydroperoxides and in the Autoxidation of Cumene with Bis(acetylacetonato)manganese(II)
Authors: Fukuzumi Shun-ichi , Ono Yoshio 
Published: July 2006

Abstract
The decomposition of 1-methyl-1-phenylethyl hydroperoxide and t-butyl hydroperoxide with Mn(II)(acac)2 and the autoxidation of cumene with Mn(II)(acac)2, Mn(III)(acac)3, and MnCO3 have been studied at 323 K. In the decomposition of the hydroperoxides with Mn(II)(acac)2, the peroxyl radicals are observed only when the initial ratio of hydroperoxide to catalyst amount exceeds a certain value. The critical phenomenon is observed in the oxidation of cumene with Mn(II)(acac)2 and also with MnCO3. A scheme for the cause of the critical phenomena has been proposed.
Measurement of Ambient Nitrogen Oxides over an Extended Period of Time by Means of a Solid Absorber Technique
Authors: Yasuoka Takashi , Mitsuzawa Shunmei 
Published: July 2006

Abstract
A new technique using a solid substance for the absorption of nitrogen oxides in the atmosphere was developed in order to obtain an average concentration of nitrogen oxides over a period of several weeks. Nitrogen oxides is absorbed by an absorbent (alkaline earth metal peroxide), and the nitrate produced in the absorber is extracted into water to determine the amount of nitrate by the ion-selective electrode method. The concentration of atmospheric nitrogen oxides is calculated from the amount of nitrate in the extract. A quantitative relation was found between the amount of nitrogen oxides collected on the absorber and that of nitrate in the extract. Hydrogen peroxide produced by the reaction of the absorber and water did not interfere with the measurement of nitrate by the ion-selective electrode technique. Practicability of this technique was demonstrated in comparison with the automatic recording analyzer (NOx meter) with the Saltzman reagent.
Stereochemistry in the Hydrosilylation of Substituted Cyclohexanones Catalyzed by Chlorotris(triphenylphosphine)rhodium and the Silica-linked Rhodium(I) Complex
Authors: Ishiyama Jun-ichi , Senda Yasuhisa , Shinoda Isamu , Imaizumi Shin 
Published: July 2006

Abstract
The homogeneous and heterogeneous hydrosilylation of simple substituted cyclohexanones catalyzed by chlorotris(triphenylphosphine) rhodium, RhCl(PPh3)3, and the silica-linked rhodium (I) complex, (Remark: Graphics omitted.), was examined. The stereoselectivity exhibited by the homogeneous catalyst was found to be nearly the same as that exhibited by the heterogeneous catalyst. The silica-linked rhodium catalyst could be re-used several times without any significant loss of the catalytic activity.
Solvolysis in Carboxamides. VII. Carboxamide Solvolysis of threo-2-Aryl-1-methylpropyl Brosylates. Reactivity-Selectivity Relationships as a Mechanistic Probe
Authors: Saito Seiki , Doihara Kenji , Moriwake Toshio , Okamoto Kunio 
Published: July 2006

Abstract
Solvolysis of a series of threo-2-aryl-1-methylpropyl brosylates (p-MeO, p-Me, H, p-Cl, m-Cl, m-CF3, and p-NO2; 1a–g) has been carried out in four carboxamides, N-methylformamide (NMF), N-methylacetamide (NMA), N,N-dimethylformamide (DMF), and N,Ndimethylacetamide (DMA), as solvent. Fractions of ks and FkΔ pathway were determined on the basis of the upward drift from the Hammett plot of the rate constant (kt); the extra acceleration by p-MeO and p-Me substituents was assigned to the FkΔ fraction. The FkΔ⁄kt values were not in agreement with the amount of retained products (threo-acetate and threo-alcohol) obtained in NMA and DMA solvolysis of 1a–c, although they should be in line with each other on the basis of the bridged-ion theory. The C(2)-deuterated phenyl derivative (1c-2-d) was solvolyzed in NMF, NMA, and DMF to give retained carboxylates (acetate or formate). However, the isotope scrambling at C(2) and C(1) of the carboxylates is incomplete, indicating that a symmetrical ion, such as a phenyl-bridged ion, can not be the intermed be the intermediate of the carboxamide solvolysis. A good correlation of logkt for substrates (1a–g) with log(% threo-acetate% erythro-acetate) or with log (% threo-acetate% olefinic products) was found for solvent systems such as NMA, DMA, and acetic acid, indicating that the reactions of all substituted substrates can be explained by intervention of a common intermediate [R+X−], a classical tight ion-pair from which the final products are derived. Such reactivity-selectivity relationship also holds between log kt’s of 1c in a series of carboxamide and logarithms of threo-erythro ratio in acetate or formate. Through-space interaction between a face of aryl ring and carbenium ion center in the transition state is considered as a possible cause for the anomalous acceleration by the activating aryl groups.
Alkylation of Benzene with Optically Active 3-Chloro-1-butanol, 3-Chlorobutanoic Acid, and Their Esters
Authors: Nakajima Tadashi , Masuda Shinji , Nakashima Satoru , Kondo Takayuki , Nakamoto Yoshiaki , Suga Sohei 
Published: July 2006

Abstract
The alkylations of benzene with optically active 3-chloro-1-butanol, 3-chlorobutanoic acid and their esters in the presence of aluminium chloride gave the corresponding 3-phenyl substituted derivatives in good optical yield. All these reactions were found to proceed with inversion of configuration at the attacking carbon atom. The products were not racemized under the conditions used, while the starting materials were racemized to a considerable extent during the reaction. Taking into account of the optical purity of the starting material recovered before the completion of reaction, net stereospecificity of each reaction was calculated to be about 90% except for the case of 3-chloro-1-butanol and its acetic ester. The high degree of stereospecificity of the reaction can be interpreted by the mechanism involving cyclic intermediate formed from the alkylating reagent and aluminium chloride.
Catalytic Hydrolysis of Dinitrophenyl Sulfate by Poly(ethylenimine) Derivativest
Authors: Kunitake Toyoki , Sakamoto Tetsuo 
Published: July 2006

Abstract
The catalytic hydrolysis of nitrophenyl sulfates by poly(ethylenimine)(PEI) derivatives was investigated at 30 °C in aqueous buffers. PEI derivatives which were made partly hydrophobic by incorporation of higher alkyl groups include alkylated PEI’s, quaternized PEI’s, and PEI’s with imidazole and hydroxamate functions. Nitrophenyl sulfates could not be cleaved by these polymers. The catalytic hydrolysis of 2-hydroxy-5-nitrophenyl sulfate by an PEI with imidazolylmethyl and dodecyl substituents failed to proceed in spite of the contrary report by Kiefer et al. 2,4-Dinitrophenyl sulfate was cleaved fairly readily by PEI derivatives. Simple sulfate transfer was observed in the case of alkylated PEI, but the catalytic hydrolysis proceeded according to the Michaelis-Menten kinetics in the case of quaternized PEI’s. Partly quaternized PEI’s showed highest catalytic efficiencies reported to date for the hydrolysis of dinitrophenyl sulfate.
Reinvestigation of the Mechanism of the Reaction of N,N-Dimethyl-aniline N-Oxide with Acetic Anhydride
Authors: Oae Shigeru , Asai Nobuyoshi , Fujimori Ken 
Published: July 2006

Abstract
The mechanism of the reaction between N,N-dimethylaniline N-oxide 1 and acetic anhydride to give 2-acetoxy-N,N-dimethylaniline 2a has been reinvestigated by means of our more refined 18O-tracer experiments. Other products of the reaction are 4-acetoxy-N,N-dimethylaniline, N,N-dimethylaniline 4, N-methylacetanilide, and bis(4-dimethylaminophenyl)methane. The reaction of 1 with 18O-labeled acetic anhydride is considered to involve the initial formation of carbonyl-18O-labeled N-acetoxy-N,N-dimethylanilinium ion 7a and the subsequent intramolecular rearrangement of 7a into 2a in which the original 18O-label in 7a is unequally partitioned into two oxygen atoms of 2a (phenolic oxygen: ethereal oxygen=ca. 4 : 1). The reaction of 1 with trichloroacetic anhydride gave solely 2-trichloroacetoxy-N,N-dimethylaniline but not any 4 which should be formed via the free radical mechanism. These observations suggest the occurrence of the two concerted path via polarized six-(major) and four-(minor) membered cyclic transition states and rule out the free radical pair mechanism which was proposed ealier by us.
Phosphinyl- and Phosphinothioylamino Acids and Peptides. V. Preparation of Dimethylphosphinothioylamino Acids and Solid Phase Peptide Synthesis
Authors: Ueki Masaaki , Inazu Toshiyuki , Ikeda Shigeru 
Published: July 2006

Abstract
The use of the dimethylphosphinothioyl(Mpt) group for protection of Nα-amino functions of amino acids has been studied as the most readily removable group in the phosphinothioyl series. The Mpt-amino acids have been prepared by the alkaline hydrolysis of Mpt-amino acid esters and Schotten-Baumann type reactions of free amino acids. The Mpt group has been removed using a solution of triphenylphosphine dihydrochloride in dichloromethane. l-Leu5- and d-Ala2, l-Leu5-enkephalins have been synthesized by a solid phase method and synthetic l-Leu5-enkephalin exibited identical activity with an authentic sample.
Raman Spectrum of the Complex of Nitrobenzene with Aluminum Chloride
Authors: Fukushima Kunio 
Published: July 2006

Abstract
Raman spectrum of the complex of nitrobenzene with aluminum chloride in a nitrobenzene solution was measured. The shift frequencies and the degree of depolarization of Raman bands of the nitrobenzene in the complex are different from those of nitrobenzene. The differences were discussed based on the prior assignment of Raman bands of nitrobenzene.
A Vapor–Liquid Equilibrium Still Suitable for Small Amounts of Samples
Authors: Takagi Sadao 
Published: July 2006

Abstract
Details are described for the apparatus and procedures for the accurate measurement of vapor–liquid equilibria by use of small amounts of samples. The new recirculation still described is a modification of the Brown’s still (Aust. J. Sci. Res., A, 5, 530 (1952)) and its total amount of operating charge is ca. 53 cm3, of which each 7 cm3 is in the vapor- and liquid-sample traps and ca. 23 cm3 is in the boiler. A method of determining an optimum value of the heating current of the boiler is described. Partial condensation of the vapor and entrainment of the liquid phase into the vapor were eliminated. Some results obtained for the system hexane+chlorobenzene at 338.15 K agreed with the thermodynamically consistent values of Brown, showing the reliability of this still operating with the samples having relative volatilities up to 13. The construction of a thermostatted sample vessel without vapor space for a Pulfrich refractometer is also illustrated which is suitable for small quantity of volatile or hygroscopic solution.
35Cl-NQR of Some Chlorocarbons and Oxochlorocarbons with a Small Ring
Authors: Mano Koichi , Matsukura Takefumi , Fujino Akira 
Published: July 2006

Abstract
35Cl-NQR of two chlorocarbons and six oxochlorocarbons, all having a small ring, were measured in the temperature range 77–300 K. The NQR line groups for the allylic and vinylic chlorine atoms appear separately in the five-membered ring compounds, whereas they are concentrated in a rather narrow region near 38 MHz in the four-membered ones. Perchlorocyclopropene possesses at least three crystal modifications at 77 K, the most stable one of which has only two lines in the temperature range examined. The line assignments, and the hyperconjugative effect in some of them, are discussed with reference to the CNDO/2 MO calculation data.
Disintegration of Sulfonated Poly(1,4-piperazinediylterephthaloyl) Microcapsules by 1-Dodecylpyridinium Chloride
Authors: Suzuki Shiro , Nakamura Takashi , Kondo Tamotsu 
Published: July 2006

Abstract
Partially sulfonated poly(1,4-piperazinediylterephthaloyl)(SPP) microcapsules were found to undergo disintegration by the action of dodecylpyridinium ions when the surfactant cation concentration exceeded a certain value which was dependent on pH of the medium. At their lower concentrations, dodecylpyridinium ions interacted with negatively charged SPP microcapsules to produce aggregation of the latter. A polyelectrolyte-type viscosity behavior was observed with the complex formed between SPP and dodecylpyridinium ions in the disintegration process of the microcapsules. Crosslinking of the terminal amino groups of SPP microcapsules prevented disintegration from taking place.
Anodic Oxidation of 2-Aminofluorene at a Platinum Electrode in Acetonitrile Solutions
Authors: Yasukouchi Kazuo , Taniguchi Isao , Yamaguchi Hiroko , Miyaguchi Katsuji , Horie Koji 
Published: July 2006

Abstract
Anodic oxidation of 2-aminofluorene in acetonitrile solutions at a Pt electrode was investigated by using electrochemical techniques and by preparative-scale electrolyses. The cyclic voltammogram of 2-aminofluorene exhibited two anodic waves, which had peak potentials at 0.45 V (Ia) and 1.15 V (IIa) vs. Ag/0.01 M AgClO4. Wave IIa was due to oxidation of protonated 2-aminofluorene. In the voltammogram of repetitive sweeps, another redox couple (IIIa/IIIc) was observed at 0.13 V for IIIa and 0.06 V for IIIc, respectively. This indicates that at wave Ia, a species which is more easily oxidized than 2-aminofluorene was produced by follow-up chemical steps. By controlled-potential electrolysis at 0.5 V of a 2-aminofluorene solution containing pyridine as a prpton acceptor, a dark green product, 3-(2-fluorenylimino)-2,3-dihydro-2-fluorenimine (5) (or 1-(2-fluorenylimino)-1,2-dihydro-1-fluorenimine (5′)), precipitated as the main product in more than 70% yield. The oxidation pathway of 2-aminofluorene (Eqs. 1—4) has been proposed on the bases of the following results: (i) The apparent n-value was 1.95, (ii) two protons/molecule of 2-aminofluorene were released in the follow-up chemical steps, and (iii) the peak potential for oxidation of 2′-amino-2,3′-difluorenylamine (3) (or 2-amino-1,2′-difluorenylamine (3′)) was in good agreement with that of wave IIIa, and the anodic oxidation of 3 (or 3′) gave the same product as that obtained by oxidation of 2-aminofluorene.
Kinetics of the Formation and Transformation of Alkoxy-derived Calcium Metasilicate
Authors: Yamaguchi Osamu , Kamata Muneaki , Shimizu Kiyoshi 
Published: July 2006

Abstract
Wollastonite(β-CaSiO3) was formed directly from the mixed powder prepared by simultaneous hydrolysis of calcium and silicon alkoxides. Crystallization isotherms were described by the Avrami equation ln(1−α)=−ktn with n=3 and the activation energy was determined as 284.5 kJ/mol. The kinetics of transformation of β- into α-CaSiO3 was best interpreted by the contracting cube equation 1−(1−α)1⁄3=kt. The value of the activation energy was 983.2 kj/mol.
Syntheses of Alkylphosphonic Esters by the Reactions of Aliphatic Thiones with Trialkyl Phosphites
Authors: Kawase Tokuzo , Yoneda Shigeo , Yoshida Zen-ichi 
Published: July 2006

Abstract
Aliphatic thiones were found to react with trialkyl phosphites to give (alkylthio)- and/or mercapto-alkylphosphonic esters. The reaction is interpreted in terms of the carbophilic attack with trialkyl phosphites at the carbon atom of the thiocarbonyl group, and the subsequent migration mechanism via the betaine intermediate.
Replacement of Methoxyl Group on the Grignard Reaction of N-(o-Methoxybenzylidene)aniline
Authors: \={O}kubo Masao , Ueda Sonoko 
Published: July 2006

Abstract
The methoxyl group of the title imine was replaced by the phenyl group on treatment with PhMgBr, the same group of N-benzylidene-o-anisidine remaining. The result was discussed on the basis of radical chain mechanism involving the initial electron-transfer.
Syntheses of Cationic Mononucleotide Analogs and Their Interaction with Polynucleotide and Polynucleotide Analogs
Authors: Shimidzu Takeo , Murakami Akira , Yamana Kazushige , Konishi Yoshiyuki 
Published: July 2006

Abstract
Cationic mononucleotide analogs were synthesized through a quaternization reaction of N-halogenoethylated derivatives of nucleic acid bases or 5′-halogeno-5′-deoxynucleoside. When they interacted with polynucleotide and polynucleotide analogs with negative charges, base-base interactions were observed. The interactions between complementary bases were stronger than the others. It is suggested that an anionic field originating from the polynucleotide or polynucleotide analog contributes to the interaction of complementary bases.
Enantioface-differentiating Reactions Using (2S,2′S)-2-Hydroxymethyl-1-[(1-alkyl-2-pyrrolidinyl)methyl]pyrrolidines as Chiral Ligands. Addition of Lithium Derivatives of Methyl Phenyl Sulfide, Acetonitrile, N-Nitrosodimethylamine, and 2-Methylthiothiazoline to Aldehydes
Authors: Soai Kenso , Mukaiyama Teruaki 
Published: July 2006

Abstract
Optically active oxiranes, β-hydroxy nitrile, β-Hiydroxy N-nitrosoamine, and thiirane were obtained (up to 72% optical purity) by the enantioface-differentiating addition of lithium derivatives of methyl phenyl sulfide, acetonitrile, N-nitrosodimethylamine, and 2-methylthiothiazoline to aldehydes using (2S,2′S)-2-hydroxymethyl-1-[(1-alkyl-2-pyrrolidinyl)methyl]pyrrolidines (1a–f) as chiral ligands. Optical purity of the products depended greatly on the reaction medium (dimethoxymethane or dimethyl ether gave the best results) and the structure of pyrrolidine moieties of 1a–f.)
F-Propene-Dialkylamine Reaction Products as Fluorinating Agents
Authors: Takaoka Akio , Iwakiri Hiroshi , Ishikawa Nobuo 
Published: July 2006

Abstract
The reaction products of F-propene and dialkylamines, mixtures of α,α-difluoroalkylamine and α-fluoro enamine, were found to be useful fluorinating agents for alcohols and carboxylic acids. These reagents were superior to the adduct of chlorotrifluoroethene and diethylamine, the so-called Yarovenko reagent, for their readier preparation and higher stability.