bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Cationic Polymerization of N-Phenylethylenimine by Various Carboxylic Acid Catalysts
Authors: Kagiya Tsutomu , Kondo Tomizo , Fukui Kenichi 
Published: July 2006

Abstract
The polymerization of N-phenylethylenimine was carried out using various carboxylic acid catalysts (pKa=0.23–4.87) in acetonitrile at 0°C. The number-average molecular weight was determined by measuring the allyl-group content in the infrared spectrum of the polymer initiated with allylformate. The relationship between the number-average molecular weight and the reduced viscosity was determined. Both the conversion and the number-average molecular weight increased with the reaction time when weak acid (pKa=2.85–4.87) was used. On the other hand, when strong acid (pKa=0.23–2.85) was used, conversion reached a limited value which increased in proportion to the amount of the catalyst. With the strong acid, the efficiency factor of the catalyst was almost unity, and was independent of the reaction time. On the other hand, with the weak acid, it was smaller than unity and increased proportionally with the amounts of the polymer formed. The rate constants of the elementary reactions were evaluated on the basis of the kinetic study. The rates of the initiation, propagation, and termination reaction increased with a decrease in the pKa of the acid. With a weak acid, the termination reaction is slow at a low temperature (below 50°C), and increases with the reaction temperature, whereas with a strong acid the termination reaction occurs markedly even at a low temperature (above 0°C), and increases slightly with the temperature. The mechanism of the termination reaction was discussed on the basis of a structural study of the end group of the polymer.
The Grignard Reaction of 3-Halotropolone Methyl Ethers
Authors: Tsuruta Haruki , Mukai Toshio 
Published: July 2006

Abstract
The Grignard reaction of the methyl ethers (I and III) of 3-bromotropolone and those (II and IV) of 3-chlorotropolone with methylmagnesium iodide or phenylmagnesium bromide were investigated. When I or II was allowed to react with methylmagnesium iodide, 2-methoxyphenyldimethylcarbinol (V) and 2-methoxy-6-isopropylphenol (VI) were obtained. The reaction of I or II with phenylmagnesium bromide afforded 2-phenyl-7-halotropones (XIII or XVII), accompanied by 2-halobenzophenones (XV or XVIII) and the triphenylcarbinol derivative (XIV). The Grignard reaction of III or IV using phenylmagnesium bromide gave 2-phenyl-3-halotropones (XVI or XIX). The mechanistic pathway for the formation of these products was discussed.
Reaction of Alkylbenzene. III. The Reaction of sec-Butylbenzene Induced by Aluminum Chloride
Authors: Itoh Kazuyoshi , Yamada Genji , Hamanaka Sawako , Ogawa Masaya 
Published: July 2006

Abstract
The products successively obtained from the reaction between sec-butylbenzene and aluminum chloride were investigated. Transalkylation was the first observed reaction, followed by the isomerization of the side chain and then by dealkylation. The isomerization of the side chain was observed in the transalkylation products of a high basicity, such as m-di- and 1,3,5-tri-substituted compounds, and not in the others. The n-butane, resulting from dealkylation, was obtained simultaneously with 2,2di-phenylbutane. On the basis of these results, the reaction mechanism was discussed.
Decomposition of Formic Acid over Metal Phthalocyanines
Authors: Tanaka Sadao , Onishi Takaharu , Tamaru Kenzi 
Published: July 2006

Abstract
The decomposition of formic acid was studied over two sorts of metal phthalocyanines: Mg-and Fe-phthalocyanines. The rates of the decomposition reactions over Mg-Phc and Fe-Phc were proportional to the pressure of formic acid, and the decomposition proceeded to dehydrogenation as well as to dehydration over these phthalocyanines. The isotope distribution in the hydrogen (H2, HD, and D2) produced by the decomposition of HCOOD leads to the conclusion that the hydrogen molecule is mainly formed between the hydrogen atom bonded to the carbon atom and that bonded to the oxygen atom in the formic acid molecule. Formic acid was adsorbed to a considerable extent over Mg-Phc in the temperature range between 70°C and 220°C. The amount of formic acid adsorbed obeyed the Langmuir adsorption isotherm, and the infrared spectra demonstrated the presence of the formate ion HGOO− on the Mg-Phc. It was also confirmed that Mg-Phc was hydrogenated during the course of the decomposition. The adsorption during the catalytic reaction was also measured. These measurements revealed that the overall rate of the reaction is proportional to the amount of formic acid adsorbed. The mechanism of formic acid decomposition was discussed on the basis of these results.
Quenching of the Scintillation from a γ-Irradiated Cyclohexane Solution Containing p-Terphenyl by Electron Scavengers, Positive Ion Interceptors and Some Hydrocarbons
Authors: Saito Tsunenari , Takahashi Koji , Sato Shin 
Published: July 2006

Abstract
The luminescence from a cyclohexane solution containing p-terphenyl irradiated with 60Co γ-rays has been quenched by various compounds. The quenching efficiencies were found to be in the following order; sulfur hexafluoride∼carbon tetrachloride&gt;nitrous oxide&gt;ethanol&gt;ammonia&gt;carbon dioxide. These compounds are known in radiation chemistry as electron scavengers or as positive-ion interceptors. Cyclopropane and ethylene have also shown an appreciable quenching ability, but n-butane has shown scarecely any. These results have been explained by assuming that ionic reactions are responsible for the luminescence from a cyclohexane-p-terphenyl scintillator.
The Analysis of the Solubility of Hydrocarbons in Water
Authors: Shinoda K\={o}z\={o} , Fujihira Masamichi 
Published: July 2006

Abstract
Enthalpy and entropy of solution of non-polar solutes in water diverge strikingly from the normal behavior established for regular solutions. This abnormality has been considered mostly due to the iceberg formation around solute molecules in water. The abnormal solubility and enthalpy and entropy of solution of non-polar solutes in water have been explained coherently by the extension of the regular solution theory, taking into account the iceberg formation of water molecules. Unlike currently accepted views on the hydrophobic bonding, it is concluded that the enthalpy of mixing (interchange) of non-polar solute with water is large, but the enthalpy decrease due to the iceberg formation of water largely cancels the enthalpy increase of mixing (interchange). Thus, the apparent enthalpy of solution is small or negative at low temperature. It is concluded that 1) the small solubility of non-polar solutes in, water is not an entropy effect, and 2) the solubility of non-polar solutes is promoted by the iceberg formation of water molecules.
β-Diketonates of a Few Lanthanide Elements
Authors: Hasan M , Kumar K , Dubey S , Misra S N 
Published: July 2006

Abstract
The reactions of isopropoxide of praseodymium and neodymium with benzoylacetone, dibenzoylmethane have been studied and the derivatives of the type M(O–iPr)2(lig.), M(O–iPr)-(lig.)2 and M(lig.)3 (where lig.=benzoylacetone or dibenzoylmethane) have been isolated. The isopropoxide-diketonates on treatment with tertiary butanol interchange their isopropoxide group with tertiary butoxide group. Anhydrous acetylacetonates of lanthanum, praseodymium, neodymium and samarium have been prepared from the reactions of the alcoholic solution of the chlorides with alcoholic solution of ammonium acetylacetonates. The molecular weights of these β-diketonates and alkoxides β-diketonates have been measured ebullioscopically in boiling benzene.
A Study on the Yield of (γ, α) Reactions with 20 MeV Bremsstrahlung
Authors: Oka Yoshinaga , Kato Toyoaki , Nomura Koichi , Saito Tatsuya , Tsai Hui-Tuh 
Published: July 2006

Abstract
The yields of the (γ, α) reactions on 7 elements up to an atomic number of 49, irradiated with 20 MeV bremsstrahlung, have been obtained through gamma-ray spectrometric measurements of the resultant activities. The yield values, as measured in absolute disintegration rates at the end of irradiation per mole per roentgen, have been plotted against atomic number of the target nuclides. The yield curve shows a maximum in the region of copper and zinc, and drops rapidly with increasing atomic number. The shape of this yield curve is similar to that for the photoalpha yield as a function of atomic number. It can be seen that the yield levels off in the region of silver and indium. A mechanism such as the direct photoelectric effect is thought to be responsible for this behavior. The yield of the (γ, α) reaction of an element amounts to only a small fraction, at most a few tenths of a per cent, of the total photonuclear yield.
Convenient Method for the Preparations of Carboxylic Thiolester and Acid Anhydride
Authors: Mukaiyama Teruaki , Katsuyama Harumi 
Published: July 2006

Abstract
The reactions of mercuric carboxylates with bivalent sulfur compounds, such as aralkyl sulfides and mercaptoles, were investigated. When mercuric acetate and aralkyl sulfides were refluxed in benzene, mercury mercaptides and aralkyl acetates were obtained. It was made clear that the reactivity of the sulfides depends on the stability of carbonium ions given by elimination of the mercapto group. Next, it was found that acetic anhydride, benzophenone and mercury phenylmercaptide were obtained in high yields by the equimolar reaction of benzophenone diphenylmercaptole with mercuric acetate. Further, the reaction was extended to the preparative method of carboxylic acid anhydrides from free acids by treating the carboxylic acids with diphenylmercury and the mercaptole. On the other hand, S-phenyl thioacetate, benzophenone and mercury mercaptide were produced in good yields when benzophenone diphenylmercaptole (2 mol) was treated with mercuric acetate (1 mol). Further, it was established that thiolesters were exclusively produced in good yields along with benzophenone and the mercury mercaptide by the reaction of benzophenone diphenylmercaptole or bis (p-chlorophenyl) mercaptole (2 mol) with free carboxylic acids (2 mol) and diphenylmercury (1 mol).
Studies on Amino-hexoses XIV. Preparation of Partially O-Carboxymethylated Chitin and Its Component 3-O- and 6-O-Carboxymethyl-d-glucosamine, and the Corresponding Glucosaminitols
Authors: Miyazaki Tsuyoshi , Matsushima Yoshio 
Published: July 2006

Abstract
3-O-carboxymethyl-d-glucosamine, 6-O-carboxymethyl-d-glucosamine, and the corresponding glucosaminitols are prepared as reference compounds in a study of a lysozyme action on a partially-O-carboxymethylated chitin. The preparation of partially-O-carboxymethylated chitin, a substrate of hen-egg white lysozyme, is also described.
Selective Chemical Cleavage of Asparagine Peptides
Authors: Shiba Tetsuo , Koda Akio , Kusumoto Shoichi , Kaneko Takeo 
Published: July 2006

Abstract
Asparagine peptide was selectively cleaved by the Hofmann rearrangement followed by an alkaline treatment at the peptide linkage in which an amino group of the asparagine residue participated. Upon reaction of N-benzyloxycarbonyl-l-alanyl-l-asparagine with one equivalent of bromine and three equivalents of aqueous sodium hydroxide solution at 60°C, 1-(N-benzyloxycarbonyl-l-alanyl)-2-oxoimidazolidine-5-carboxylic acid was obtained in quantitative yield. When this was treated with an aqueous methanolic sodium hydroxide solution at room temperature, a cleavage reaction occurred to give N-benzyloxycarbonyl-l-alanine and 2-oxo-imidazolidine-5-carboxylic acid. Under the same condition of the rearrangement, N-benzyl-oxycarbonyl-l-asparaginyl-l-phenylalanine was converted to 1-benzyloxycarbonyl-2-oxoimidazo-lidine-5-carbonylphenylalanine. Since glutamine peptide could not give the corresponding ring compound, this cleavage reaction was found to be specific to asparagine peptide.
Electron Spin Resonance of X-Irradiated Single Crystals of Zinc Acetate Dihydrate: Hindered Rotation of Methylene Group in a Free Radical CH2COO−
Authors: Ohigashi Hiroji , Kurita Yukio 
Published: July 2006

Abstract
Electron spin resonance spectra of X-irradiated single crystals of zinc acetate dihydrate have been studied at 9.2 Gc in the temperature range from 77°K to 380°K. The radicals trapped at 77°K are CH3 and CH2COO−. The former disappears above 150°K. The latter is stable and persists up to 370°K. The principal values of hyperfine coupling constants for two indetical hydrogens of the radical CH2COO− have been found to be 10.5, 20.6 and 33.4G. The CH2 group in the radical undergoes restricted rotation about the C–C bond. Analysis of the ESR spectra at different temperatures with a modified Bloch equation shows the activation energy and the frequency factor for the restricted rotation to be 5.8±0.2 kcal/mol and (4.4±2.7)×1012 sec−1, respectively.
Studies on the Substrate Specificity of Egg White Lysozyme. II. Mode of the Enzymatic Action on Partially-O-carboxymethylated Chitin
Authors: Miyazaki Tsuyoshi , Matsushima Yoshio 
Published: July 2006

Abstract
Partially-O-carboxymethylated chitin was found to be a soluble substrate of hen egg white lysozyme. The products of the lysozyme action were analyzed by gel filtration and by ion-exchange chromatography. The reducing ends of the saccharides produced by the enzyme were the N-acetyl-glucosamine residue or the 3-O-carboxymethyl-N-acetyl-glucosamine residue. 6-O-Carboxymethyl-N-acetyl-glucosamine never appeared as a reducing end. The O-substituted disaccharide detected in the reaction products was 6′-O-carboxymethyl-di-N-acetyl-chitobiose. The results of the reducing-end analyses and the finding that none of the monomers were formed except for the unsubstituted N-acetyl-glucosamine, while an O-substituted dimer was formed as is mentioned above, are in conformity with the conformation of the enzyme-substrate complex proposed by Blake et al. as a result of their X-ray crystallographic investigations.
Diffuse Reflection Spectra of Some Dinitrobiphenyl Complexes
Authors: Abe Kunihiro , Matsunaga Yoshio , Saito Gunzi 
Published: July 2006

Abstract
The 4,4′-dinitrobiphenyl complexes with benzidine and tetramethylbenzidine, in which the long axes of the component molecules are known to be perpendicular to each other, were examined for the diffuse reflection spectra. The deep coloration in these complexes was found to be due to the appearance of broad, weak charge-transfer absorptions.
Polarized Absorption Spectra of Single Crystals of Ion Radical Salts. I. Molecular Compounds of 7,7,8,8-Tetracyano-p-quinodimethane with N,N,N′,N′-Tetramethyl-p-phenylenediamine and N,N-Dimethyl-p-phenylenediamine
Authors: Kuroda Haruo , Hiroma Shoji , Akamatu Hideo 
Published: July 2006

Abstract
Polarized absorption spectra in the 10–40 kK region were observed on single crystals of the molecular compounds of tetracyano-p-quinodimethane(TCNQ) with tetramethyl-p-phenylenediamine (TMPD) and with dimethyl-p-phenylenediamine (DMPD). These molecular compounds possess an ionic structure in the ground state. A strong, broad absorption band appears in the near-infrared region of the crystal spectra with a polarization parallel to the crystal axis along which the component ions are alternately stacked making their molecular planes parallel to each other. The absorption maximum of this band is located at 7.7 kK in TMPD·TCNQ and at 8.5 kK in DMPD·TCNQ. These bands are assigned as a one associated with the charge transfer from TCNQ− ion to the positive ion of the donor. Other absorption bands found in the spectra can be assigned as local excitation bands associated with the intramolecular transitions of the component ions. However, they are found to be considerably broadened and appreciably shifted to higher energy as compared with the solution spectrum of each component ion.
On the Isomerization of Dimers of Perchloro-(3,4-dimethylenecyclobutene) as Revealed by X-ray Methods
Authors: Furusaki Akio 
Published: July 2006

Abstract
The isomerization of several dimers of perchloro-(3,4-dimethylenecyclobutene) (I) has recently been reported by Fujino et al. Of these dimers, one (II) is transformed to other isomers (IIIa) and (IIIb) by means of pyrolysis at ca. 200°C. When heated to ca. 250°C, IIIa and IIIb are further converted into a fourth isomer (IV). The present X-ray study has revealed that II corresponds to perchloro-(3,4,7,8-tetramethylene-tricyclo[4.2.0.02.5]octane), as supposed from the chemical evidence, and IV, to perchloro-(4,8-dimethylene-tricyclo[3.3.2.01.5]deca-2,6-diene). It has been further established, from the results of the X-ray analysis of the dichloride of IIIa with the help of the chemical information, that IIIa and IIIb have the same two-dimensional chemical structure, perchloro-(3,4,7,8-tetramethylene-cycloocta-1,5-diene), rather than perchloro-(2,3,7,8-tetramethylene-bicyclo[4.2.0]octa-4-ene) which was speculated by Fujino et al., and that IIIa and IIIb are different from each other in the conformation of the cyclooctadiene ring. These structures for II, IIIa, IIIb, and IV give a reasonable explanation of the mechanism of the successive isomerization reactions mentioned above.
The Hydration and Crystallization of ρ-Alumina and Alumina-gel in Aqueous Solutions of Various Basic Reagents
Authors: Yamaguchi Goro , Chiu Wen-Chau 
Published: July 2006

Abstract
Alumina gel, boehmite gel, ρ-alumina, η-alumina, and γ-alumina were treated with aqueous solutions of various inorganic and organic reagents at temperatures below 100°C. Boehmite gel, η-alumina and γ-alumina were found to show no change upon this treatment, while alumina gel and ρ-alumina either remained unchanged or changed into fairly well-crystallized boehmite, boehmite gel, gibbsite, bayerite, or nordstrandite, according to the treating conditions. It has been newly established that water-containing pyridine and aniline, the aqueous solution of hydrazine hydrate, and the aqueous solution of o, m-phenylenediamine are effective in forming fairly well-crystallized boehmite, nordstrandite, and gibbsite respectively.
Spectroscopic Studies of Mixed Amine Carbonyl Complexes of d6 Structure. I. Visible and Ultraviolet Absorption Spectra of Diamine-tetracarbonyl Complexes of Chromium(0), Molybdenum(0) and Tungsten(0)
Authors: Saito Hide , Fujita Junnosuke , Saito Kazuo 
Published: July 2006

Abstract
Chromium(0), molybdenum(0) and tungsten(0) complexes of [M·(CO)4AA]0 type (AA=ethylenediamine (en), l-propylenediamine (l-pn), trimethylenediamine (tn), bipyridyl (bp), and phenanthroline (phen); l-pn and tn derivatives are new compounds) have been synthesized and their absorption spectra, rotatory dispersion (RD) and circular dichroism (CD) measured in methanol at room temperature. The nature of the absorption bands has been discussed by comparing them with one another and with those of hexacarbonyl- and piperidinepentacarbonyl complexes of these elements. The peaks in the region 23000 to 25000 cm−1 seem to be due to spinallowed d–d transition. The bands at 30000 to 33000 cm−1 appears to correspond to the metal to carbonyl charge transfer band of hexacarbonyls at ca. 36000 cm−1. Besides them, complexes of aromatic amines (bp and phen) show broad and strong bands at 21000 to 22000 cm−1 which seem to owe to metal to amine charge transfer.
Complexes of Copper Chlorides with Benzophenoneimine
Authors: Misono Akira , Osa Tetsuo , Koda Seiichiro 
Published: July 2006

Abstract
We tried to prepare complexes of copper chlorides with benzophenoneimine. The complex CuCl2·2Ph2C=NH and the complex CuCl·Ph2C=NH were newly prepared, and some of their properties were investigated by physico-chemical techniques. Besides these, two other complexes were obtained, but they were not completely stoichiometric compounds.
Electrometric Studies on the Reaction between Pb(II) and Alkali Meta-Vanadate
Authors: Saxena R S , Sharma C P 
Published: July 2006

Abstract
The reaction between Pb2+ and VO3− was investigated by means of electrometric techniques involving potentiometric, pH-metric and conductometric titrations between Pb(NO3)2 and NaVO3 at several concentrations, with each of the reagents alternately used as titrant. The sharp breaks and inflections obtained in titration curves evidenced the formation of lead metavanadate having the molecular composition PbO·V2O5 at pH range 4.25–5.25. The precipitation of the compound has been found to be almost quantitative and the titration results are very accurate and reproducible.
Asymmetric Hydrogenating Activity of Modified Raney Nickel Catalyst
Authors: Tatsumi Susumu 
Published: July 2006

Abstract
In the asymmetric hydrogenation of methyl acetoacetate to methyl 3-hydroxybutyrate using Raney nickel catalysts modified with optically active hydroxy dicarboxylic acids and related compounds (for example, Y. Izumi, S. Tatsumi and M. Imaida, Bull. Chem. Soc. Japan, 39, 2223 (1966)), the relationship between the asymmetric activities of the catalysts and the chemical or stereochemical structures of modifying reagents was discussed on the basis of data obtained previously. The effects of the conditions used for modification upon the asymmetric activity were also discussed inclusively. Moreover, the stability of asymmetric activity in the modified catalysts has been found to be very excellent.
The Cyclization of Malononitrile and Ketones by Ammonium Acetate
Authors: Sakurai Akio , Midorikawa Hiroshi 
Published: July 2006

Abstract
Hitherto various heterocyclic compounds have been synthesized by the reaction of ketones with ethyl cyanoacetate or ethyl acetoacetate in the presence of excessive ammonium acetate. On the basis of these facts, the reaction of malononitrile with ketones by ammonium acetate was carried out; aminopyridine derivatives, such as 2, 4-diamino-3, 5-dicyano-6-alkylpyridines (I) and 2-amino-3-cyano-4, 6-dialkylpyridines (II), were thus obtained.
Synthesis of Natural Human Angiotensin
Authors: Aoyagi Haruhiko , Arakawa Kikuo , Izumiya Nobuo 
Published: July 2006

Abstract
The synthesis of a decapeptide, H-l-Asp-l-Arg-l-Val-l-Tyr-l-Ile-l-His-l-Pro-l-Phe-l-His-l-Leu-OH, which has an amino acid sequence assumed by Arakawa et al. for natural human angiotensin I, has been performed. The chemical and biological properties of the synthetic product have shown to be in agreement with those of the natural material, thus the structure of human angiotensin I has been confirmed by the present synthesis.
The Dimerization of Butadiene by Palladium Complex Catalysts
Authors: Takahashi Shigetoshi , Shibano Toshiki , Hagihara Nobue 
Published: July 2006

Abstract
It has been found that palladium-phosphine complexes coordinated by dienophile and tetrakis-(triphenylphosphine) palladium catalyzed the linear dimerization of butadiene. The dimerization of butadiene with bis(triphenylphosphine)(maleic anhydride)palladium in aprotic solvents, such as benzene, tetrahydrofuran, and acetone, gave octatriene-1,3,7 selectively in good yields. In such alcohols as methanol, ethanol, and isopropanol, butadiene was converted to 1-alkoxyoctadiene-2,7 and/or octatriene-1,3,7, depending on the nature of the alcohols employed. The dimerization in secondary amines, such as morpholine, piperidine, and diisopropylamine, gave butadiene dimer-amine adducts of the R2N(C8H13) type, while that in primary amines, such as aniline and n-butylamine, gave a mixture of RNH(C8H13) and RN(C8H13)2. Phenoxy- and acetoxyoctadiene were also obtained from the reactions in phenol and acetic acid respectively.