bluuebunny/crossref_metadata_2025_split huggingface dataset:
Measurements of Acid-strength Distribution beyond H0=−8.2 of Silica-Alumina Catalysts by UV-Spectrophotometric n-Butylamine Titration Method
Authors: Take Jun-ichiro , Tsuruya Tetsuo , Sato Tetsuo , Yoneda Yukio 
Published: July 2006

Abstract
A new UV-spectrophotometric n-butylamine titration method was proposed for measuring acid-strength distribution of acid sites on solid acid catalysts. The method can provide information on acid-strength distribution of acid sites beyond H0=−8.2, which can not be obtained by the conventional visual n-butylamine titration method. Acid-strength distributions were measured for a series of silica-alimina catalysts differing in sodium content, using 4-benzeneazodiphenylamine (pKa=1.5), trans-benzalacetophenone (pKa=−5.6), 4-nitrotoluene (pKa=−10.5), and 2,4-dinitrotoluene (pKa=−12.8) as indicators. The results revealed that about one-half of the acid sites on an unpoisoned silica-alumina catalyst lay in the H0 region from −10.5 to −12.8, and the strongest ones in the H0 region beyond −12.8. The strong acid sites were eliminated with the modification of acid-strength distribution as the catalyst was poisoned with sodium ions. UV spectra of the above indicators in adsorbed state were discussed.
Titrimetric Determination of Iron(II), Molybdenum(V), and Thallium(I) with Potassium Chlorate Using Redox Indicators
Authors: Rao G Gopala , Radhakrishnamurty C 
Published: July 2006

Abstract
Accurate and convenient procedures have now been devised for the titrimetric determination of iron(II), molybdenum(V), and thallium(I) with potassium chlorate using visual indicators. These procedures are more advantageous than the procedures involving bromate. Further, chlorate is to be preferred as it is more inexpensive than bromate or iodate. Potassium chlorate is now obtainable at the purity required of a primary standard at a nominal cost. The chlorate titration procedure for iron(II) works satisfactorily even in the presence of organic materials such as oxalic acid, tartaric acid, and citric acid, so that it can be used for the determination of ferrous iron in pharmaceutical preparations or of ferric iron after reduction. It has been observed by us that oxygen of the air interferes in the titration of iron(II) in 6–7m hydrochloric acid medium using naphthol blue black or methyl orange as a redox indicator but not in the titration of iron(II) in sulphuric acid medium using ferroin as an indicator. An inert atmosphere is not necessary for the titration of molybdenum(V) and thallium(I) in hydrochloric acid medium.
The Synthesis of 2,3-Dimethoxy-5-methyl-p-benzoquinone
Authors: Sato Kikumasa , Inoue Seiichi , Sato Haruhito 
Published: July 2006

Abstract
2,3-Dimethoxy-5-methylbenzoquinone, the key intermediate of the synthesis of coenzyme Q, was synthesized via two new routes. The methylation of 5-nitrovanillin gave 5-nitroveratraldehyde, which was then catalytically reduced to afford 5-aminohomoveratrol. The oxidation of 5-aminohomoveratrol gave 2,3-dimethoxy-5-methylbenzoquinone. 2,3,4-Trimethoxyphenol was obtained by the decarboxylation of 3,4,5-trimethoxysalicylic acid. This was converted via Mannich reaction to 2,3,4-trimethoxy-6-methylphenol, which was then easily oxidized to 2,3-dimethoxy-5-methylbenzoquinone.
Elektrochemische Untersuchungen über den Litheffekt
Authors: Suga Tsuneo 
Published: July 2006

Abstract
Es wurde der Mechanismus des Litheffektes diskutiert. Um dieses Problem zu behandeln, wäre es nützlich, daß man sich den Litheffekt in Verbindung mit Lithemulsion und Lithentwickler überlegt. Nach Yule beschleunigen die bei der Entwicklung entstandenen Oxydationsprodukte des Hydrochinons die Lithentwicklung. In der vorliegenden Arbeit wurde die Rolle der Oxydationsprodukte weiter vom Standpunkt der Oxydation aus elektrochemisch untersucht. Die Oxydationsprodukte beschleunigen die Entwicklung der stärker belichteten Körner durch die Herabsetzung des Ladungsbarriereeffektes und hemmen die Entwicklung der schwächer belichteten Körner durch die Oxydationsfähigkeit. Wenn diese beiden Faktoren miteinander ins Gleichgewicht gebracht werden, könnte man einen guten Litheffekt erhalten. Nach dieser Ansicht konnte man die Ursache für den guten Litheffekt einer Lithemulsion gut erklären.
Adsorption of Sodium and Calcium Dodecyl Sulfates at the Surface of Their Aqueous Solutions
Authors: Sasaki Jun , Tajima Kazuo , Sasaki Tsunetaka 
Published: July 2006

Abstract
Adsorption of sodium dodecyl sulfate (NaDS) and calcium dodecyl sulfate (Ca(DS)2) at the aqueous surface was measured by a radiotracer method using tritium labelled compounds at constant ionic strength of 1×10−2 and 7.5×10−3 adjusted by the addition of NaCl and CaCl2, respectively. The adsorbed amounts increased with increasing concentration of dodecyl sulfates in both cases, and approached saturation values of 3.65×10−10 mol/cm2 at 25°C for NaDS and 3.8×10−10 mol/cm2 at 55°C for Ca(DS)2. The amounts calculated from surface tension data by applying the Gibbs adsorption isotherm were confirmed to be in good agreement with the values directly measured. The adsorbed amounts of chloride ion, generally assumed to be zero, were confirmed to be negligible in the concentration region from zero up to critical micelle concentration.
Study of Dielectric Relaxation Mechanism and Mutual Viscosity in Some Aromatic Compounds
Authors: Mehrotra N K , Pant T C , Saxena M C 
Published: July 2006

Abstract
Relaxation time and mutual viscosity of seven substituted benzenes, p-toludine, o-nitroaniline, 2,4-dichloroanisole, 2,3-dichloroanisole, 2,5-dichloronitrobenzene, 3,4-dichloronitrobenzene, and 4-chloro-1,3-dinitrobenzene have been determined in the 3.13 cm (9585 MHz) microwave region, and at three different temperatures 20, 30, and 40°C. Correlation of mutual viscosity with relaxation time leads to the conclusion that the mutual viscosity is a better representation of the resistance to the rotation of the individual solute molecule.
Solvent Effects under High Pressures. IV. A Procedure for the Estimation of Solvation in the Transition State
Authors: Kondo Yasuhiko , Ohnishi Masaru , Tokura Niichiro 
Published: July 2006

Abstract
The rate constants and activation parameters were measured for the reaction of pyridine with benzyl bromide in various solvents. The rate constants were better correlated to the activation volumes than to the activation entropies. The linear free-energy relationships were observed in the plots of the logk values of some Menschutkin reactions vs. the logk values of the present reaction in various solvents. Corresponding to their good correlations between the values of log k and of their pressure derivatives for the present reaction, the values of (z·ΔP), which are the slopes of the plots of ΔV0\eweq vs. KV0, increased with the increase in the slopes of the above linear free-energy relationships. The activation volumes in various solvents are linearly correlated to their pressure derivatives. An equation which predicts the relationship has been derived. Using this equation, the solvation number in the activated complex and the average pressure within its cosphere have been estimated to be ca. 4 and 910 (kg. cm−2) respectively. Based on these results, discussions have been given on the solvation in the transition state for the present reaction.
Studies of Acyl and Thioacyl Isocyanates. X. The Cycloaddition Reaction of Benzoyl and Thiobenzoyl Isocyanates with Benzaldazines
Authors: Tsuge Otohiko , Kanemasa Shuji 
Published: July 2006

Abstract
Although benzoyl isocyanates do not react with benzaldazines at room temperature, the criss-cross cycloadducts are formed if the reaction is carried out in refluxing xylene. On the other hand, thiobenzoyl isocyanate behaves quite differently toward the same azines. It reacts easily with azines at room temperature to afford to mono- or the bis(4+2) cycloadducts depending on the nature of the substituent in the azines. We found that the mono (4+2) cycloadduct can be thermally dissociated into its components. Neither benzoyl isocyanate nor thiobenzoyl isocyanate react with aromatic ketazines.
Studies on Nitro Carboxylic Acids. II. Synthesis of α,β-Unsaturated β-Nitro Carboxylic Esters
Authors: Shin Chung-gi , Yonezawa Yasuchika , Narukawa Hirotoshi , Nanjo Katsumi , Yoshimura Juji 
Published: July 2006

Abstract
Synthetic studies on ethyl α,β-unsaturated β-nitrocarboxylates (IV) through two routes are described. Ethyl α-hydroxy-β-nitrocarboxylates (II) obtained by the reactions of ethyl α,β-unsaturated carboxylates with fuming nitric acid or by those of nitroparafins with ethyl glyoxylate, were treated with acetic anhydride to afford ethyl α,-acetoxy-β-nitrocarboxylates (III), which were subsequently converted into IV by treatment with bases used as catalysts. On the other hand, IV was also obtained from ethyl α-chloro-β-nitrocarboxylates derived from the reactions of ethyl α,β-unsaturated carboxylates with nitryl or nitrosyl chloride. The structural assignments of IV were made on the basis of elementary analysis, infrared spectra and its conversion into the corresponding α-methoxy derivatives.
Studies on Amino-hexoses. XV. Synthesis of Deoxy-N-acetyl-muramic Acid
Authors: Arita Hitoshi , Fukukawa Kiyofumi , Matsushima Yoshio 
Published: July 2006

Abstract
Benzyl 2-acetamido-6-O-acetyl-4-chloro-2,4-dideoxy-3-O-[d-1-(methyl carboxylate)ethyl]-α-d-galactopyrano-side and benzyl 2-acetamido-4,6-dichloro-2,4,6-trideoxy-3-O-[d-1-(methyl carboxylate) ethyl]-α-d-galactopyranoside were prepared by the reaction of sulfuryl chloride on N-acetyl-muramic acid derivatives. 2-Acetamido-2,4-dideoxy-3-O-(d-1-carboxyethyl)-d-xylohexo-pyranose (N-acetyl-4-deoxy-muramic acid) and 2-acetamido-2,4,6-trideoxy-3-O-(d-1-carboxyethyl)-d-xylohexo-pyranose (N-acetyl-4,6-dideoxy-muramic acid) were prepared by the reduction of these chlorodeoxy derivatives with tri-n-butyltin hydride.
Studies on Aminosugars. XXXII. Synthesis of 3′, 4′-Dideoxykanamycin B
Authors: Umezawa Sumio , Umezawa Hamao , Okazaki Yasushi , Tsughiya Tsutomu 
Published: July 2006

Abstract
Penta-N-ethoxycarbonylkanamycin B (1) prepared from kanamycin B was treated with 2,2-dimethoxypropane in DMF to give a 3′,4′;4″,6″-di-O-isopropylidene derivative (3). Subsequent benzoylation afforded a 2″-O-benzoyl derivative (4), Removal of the isopropylidene groups from 4 followed by controlled isopropylidenation afforded the corresponding 4″,6″-O-isopropylidene derivative (5), which was then transformed to a 3′,4′-di-O-mesyl derivative (6). Treatment of 6 with sodium iodide and zinc dust in DMF gave the desired 3′,4′-unsaturated derivative (7). Hydrogenation and removal of the protecting groups gave the title compound. The 3′,4′-dideoxykanamycin B expectedly showed remarkable activity against kanamycin-resistant bacteria as well as sensitive strains.
Linear Conjugated Systems Bearing Aromatic Terminal Groups. X. Syntheses and Electronic Spectra of α,ω-Di-1-naphthyl- and α,ω-Di-2-naphthylpolyenes
Authors: Yasuhara Akio , Akiyama Shuzo , Nakagawa Masazumi 
Published: July 2006

Abstract
Syntheses of di-1-naphthyl- and di-2-naphthylpolyenes (In, n=1–4,6 and In′, n=1–6) have been carried out by the Wittig reaction. Naphthaldehydes (III and III′), 3-naphthyl-2-propenals (V and V′), 5-naphthyl-2,4-pentadienals (VI and VI′) and muconic aldehyde were used as carbonyl components. Naphthylmethyltriphenylphosphonium halides (IV and IV′), 3-naphthyl-2-propenyltriphenylphosphonium bromides (XI and XI′) and 5-(2-naphthyl)-2,4-pentadienyltriphenylphosphonium bromide (XII′) were synthesized and converted into the corresponding phosphoranes by reaction with phenyllithium. The reaction of carbonyl moiety with phosphorane by a proper combination afforded dinaphthylpolyenes (In and In′). The electronic spectra of di-1-naphthylpolyenes (In) showed broad and structureless absorption curves. In contrast, the absorption curves of di-2-naphthylpolyenes (In′) exhibited a distinct vibrational fine structure. It was found that the bathochromic shift of the longest-wavelength peak (λmax) along with the increase of the number of double bond (n) can be expressed by the following empirical formula:
λmax=45.4n0.7+302 (nm in tetrahydrofuran)
Optically Active Triptycenes. II. Synthesis of Optically Active 7-Substituted 2,5-Dimethoxytriptycenes
Authors: Ogura Fumio , Sakata Yoshiteru , Nakagawa Masazumi 
Published: July 2006

Abstract
A series of optically active 7-substituted 2,5-dimethoxytriptycenes has been prepared from (+)-2,5-diacetoxy-7-carboxytriptycene (I) as suitable model compounds for a study of the relationship between their structure and optical rotatory properties. The single crystal of 2,5-dimethoxy-7-dimethylaminotriptycene hydrobromide (VII) thus prepared was subjected to X-ray crystallographic analysis and proved to have 1R, 6S absolute configuration. Consequently, it became clear that all compounds of this series have the same 1R, 6S configuration. They showed without exception positive optical rotation in visible wavelength region.
The Allylic Rearrangement. II. Reactions of 5,5,5-Trichloro-3-penten-2-one with Nucleophiles
Authors: Takeda Akira , Tsuboi Sadao , Moriwake Takashi , Hirata Eiji 
Published: July 2006

Abstract
Reactions of 5,5,5-trichloro-3-penten-2-one (1) with a number of nucleophiles have been carried out. It was found that the Grignard reagents (5) primarily attacked the carbonyl carbon of 1 yielding the corresponding tertiary alcohols (7). The reaction sequence of ethylmagnesium bromide (5a) is given as an example. The reaction of 5a with 1 gave 6,6,6-trichloro-3-methyl-4-hexen-3-ol (7a) as the major constituent of the primary product. The hexenol 7a readily underwent the allylic rearrangement by heating at distilling temperature (88–90°C/6 mmHg) to afford 4,6,6-trichloro-3-methyl-5-hexen-3-ol (8a), which was in turn converted into 6,6-dichloro-3-methyl-3,4-epoxy-5-hexene (9a) by treatment with sodium methoxide. The stereoselective synthesis of dl-erythro-4,6,6-trichloro-3-methyl-5-hexen-3-ol (8a-I) was achieved by using 3,5,5-trichloro-4-penten-2-one (3) as the starting material in place of 1. dl-trans-6,6-Dichloro-3-methyl-3,4-epoxy-5-hexene (9a-I) was derived by the cyclization of 8a-I with a base. The stereochemistry of 8a and 9a was discussed on the basis of NMR data. Nucleophiles such as methanol, hydrogen chloride, anilines, thiophenol, sodium acetate, sodium phenolate, and diethyl sodiomalonate gave the products of the conjugate addition (15). Ethyl sodioacetoacetate gave 2-chloro-3-acetonyl-4-ethoxycarbonyl-5-methylfuran (17).
The Acid-catalyzed Degradation of Methyl 2,3,4,5-Tetra-O-acetyl-α-l-xylo-2-hexulopyranosonate. A Model for the Degradation of l-xylo-Hexulosonic Acid
Authors: Goshima Kazuaki , Maezono Norihide , Tokuyama Kanji 
Published: July 2006

Abstract
The degradation reaction of l-xylo-hexulosonic acid (1) was studied, using methyl 2,3,4,5-tetra-O-acetyl-l-xylo-2-hexulopyranosonate (11) as a model compound. The degradation of 11 proceeded via two pathways, 11→α,β-unsaturated ketone compound→a furan compound (path a) and 11→a dihydropyrone compound→further decomposed products (not furans) (path b). The major pathway was path a in benzene and path b in water. The results supported the idea that the acid-catalyzed degradation of l-ascorbic acid (2) to furans would not proceed via 1, but directly.
High Modulus Carbon Fibers from Pitch Materials
Authors: Otani Sugio , Watanabe Shoji , Ogino Hosaku , Iijima Kazuo , Koitabashi Teruyo 
Published: July 2006

Abstract
Preparation of high modulus carbon fibers from pitch materials was attempted by two methods, stretchgraphitization and the use of a special pitch material composed of highly oriented constituent molecules. It was shown that carbon fiber of high tensile strength and of high modulus can be prepared by stretch-graphitization, and high modulus carbon fiber by heat treatment without stress from the pitch of tetrabenzophenazine. The property of precursor was found to have an important effect on the structure of the fiber.
Study of Grinding Reaction of the System of Fine Particle Silica and Basic Zinc Carbonate by X-Ray Silicon K-Emission Band Spectra
Authors: Motoyama Muneyuki , Hashizume Genzo 
Published: July 2006

Abstract
Usefulness of X-ray emission spectrometry was demonstrated in a study of the grinding reaction of the system of fine particle silica and basic zinc carbonate. SiKα bands of the ground mixtures shifted toward the lower energy side relative to that of the fine particle silica, whearas SiKβ bands toward the opposite side. These band shifts were regarded as a measure of the reaction progress. The SiKβ band shift was shown more distinctly than the Kα band shift and explained as come from a decrease in the s-character of the bond caused by the chemical bonding of the zinc atom with the fine particle silica. The Kβ band shift was also correlated with the destabilization energy relative to the fine particle silica after C. G. Dodd and G. L. Glen. The band shifts indicated that the final product of this grinding reaction was amorphous zinc silicate-like compound. The correspondence of the X-ray band shifts with the infrared spectral shifts was also shown.
Geometrical Structures of Excited States of Conjugated Molecules: Benzene, Naphthalene, Azulene, and Heptalene
Authors: Fujimura Yuichi , Yamaguchi Hiroyuki , Nakajima Takeshi 
Published: July 2006

Abstract
A semiempirical SCF CI MO method used in combination with the variable bond-length technique, which has proved to be quite successful in predicting the ground-state geometrical structures of conjugated molecules, has been applied with modifications suitable to their excited states. The values of the parameters appearing in the expression of the resonance integral were adjusted so as to reproduce both the absorption and fluorescence spectra of benzene. The lower three singlet states (1B2u, 1B1u, and 1E1u) and the lowest triplet state (3B1u) of benzene, the lower two singlet states 1B1u and 1B2u) of naphthalene, the lower two singlet states (1B2 and 1A1) of azulene, and the lowest singlet state of heptalene are examined. It is predicted that the 1B1u and 3B1u states of benzene have the antiquinoidal and quinoidal conformations of the D2h symmetry respectively, and that the symmetry of the lowest singlet state of heptalene is higher than that (C2h) of the ground state.
The Effects of the Crystal-structural Transformation on the Chemical Behavior of 64Cu Recoil Atoms in α-Copper Phthalocyanine
Authors: Kudo Hiroshi 
Published: July 2006

Abstract
The Stage-II annealing process of 64Cu recoil atoms in neutron-irradiated α-copper phthalocyanine was carefully examined. The isothermal annealing curve above 270°C showed anomalous inflection point. It was found that the Stage-II annealing process of the α-crystal consisted of a “normal” monotonous annealing process and a “delayed” process caused by the crystal-structural transformation. The results of a kinematic analysis suggested that the fluctuation of the matrix and the change in the crystalographic factors due to the structural transformation play a triggering role in the delayed annealing reaction.
Semiconducting Anion-radical Salts Derived from 3,3′5,5′-Tettrahalo-p-diphenoquinones
Authors: Matsunaga Yoshio , Narita Yoshihiro 
Published: July 2006

Abstract
3,3′5,5′-Tettrahalo- and 3,3′,5,5′-tetrabromo-p-diphenoquinones were found to form series of complex anion-radical salts of the M+(Q2)− or M+2(Q3)2− type with various onium cations. These complex salts are darkcolored, almost black in many cases, and show electronic absorptions extending into the rock-salt region. In addition, bluish green-colored simple salts could be isolated with a few cations. The complex salts exhibit electrical resistivities in orders from 10 to 104 ohm cm at room temperature. Neither the pattern due to the quinone molecule nor that due to the semiquinone ion is present in their vibrational spectra. A single carbonyl stretching vibration band appears around 1600 cm−1, intermediate between that in the quinone and that in the semiquinone salt.
Distribution Studies of Alkali Metal Picrates
Authors: Iwaghido Tadashi 
Published: July 2006

Abstract
Alkali metal picrates are extractable from an aqueous solution into nitrobenzene. The picrates exist mainly as the dissociated form in both the aqueous and the nitrobenzene phases, whereas picric acid exists mainly as the undissociated form in the organic phase. The distribution ratio of the picrates and picric acid at any pH can well be explained in terms of these equilibrium constants. The distribution coefficient of picric acid is evaluated to be 102.63.
Kinetics and Mechanisms of the Reaction of Fe(III) with Variamine Blue, [N-(p-Methoxyphenyl)phenylenediamine] in Aqueous Perchlorate Media
Authors: Imamura Taira , Fujimoto Masatoshi 
Published: July 2006

Abstract
The kinetics of the non-complementary reaction of Fe(III) with Variamine Blue was studied under nitrogen atmosphere in perchlorate media of ionic strength μ=1.0m. The iminoquinone form of Variamine Blue was followed spectrophotometrically by a stopped-flow technique. The rate constants of the stepwise reaction, Fe(III)+(V.B.) \oversetkα\ightleftarrows Fe(II)+(V.B.)sox, Fe(III)+(V.B.)sox \oversetkβ→ Fe(II)+(V.B.)ox+2 H+, were evaluated to be kα=3.28×102 and kβ=4.29×102 m−1 sec−1 at pH\simeq2.2 and 25°C. The apparent activation energy was 10±1 kcal·mol−1 for both kα and kβ. The formation rate was not seriously affected by hydrogen ion concentration (pH 2.2–0.77).
Complexes Coordinated by 2,2′-Bipyridine Negative Ion. II. Sodium 2,2′-Bipyridinetetracarbonylchromium, -molybdenum, and -wolfram
Authors: Kaizu Youkoh , Kobayashi Hiroshi 
Published: July 2006

Abstract
Bipyridinetetracarbonylchromium, -molybdenum and -wolfram and their related complexes were reduced with sodium metal in tetrahydrofuran. Some products in the first stage of reduction were isolated. On the basis of the electronic absorption spectrum and the electron spin resonance, the complex formed in the reduction was concluded to be a complex coordinated by mononegative ion of bipyridine. Metal dσ orbital in the complex is still higher than bipyridine π* orbital, even if it is fairly lowered by a positive charge arising from the “metal to carbonyl” back-donation. Trapped electrons in the bipyridine π* orbital are, however, readily transferred into dσ orbital depending upon molecular environment. This gives rise to the formation of a pentacoordinate complex or complex dimer evolving carbon monoxide.
Studies on New Derivatives of 8-Quinolinol as Chelating Agents. I. Syntheses, Coloration Reaction with Metal Ions and Acid Dissociation Constants of Some Azomethine and Aminomethyl Derivatives
Authors: Hata Takehisa , Uno Toyozo 
Published: July 2006

Abstract
Azomethine derivatives of 8-hydroxyquinoline-2-carbaldehyde with aromatic and aliphatic amines and their aminomethyl derivatives were synthesized for the purpose of investigating their applications as analytical reagents. Spot tests with metal ions revealed that azomethine derivatives form intensely colored chelates, whereas aminomethyl derivatives form less intensely colored chelates. The acid dissociation constants were determined by means of potentiometric titration in 50 v/v% aqueous dioxane solution at 25±0.1°C. The values of pKNH+ and pKOH of 8-hydroxyquinoline-2-carbaldehyde, 2-(o-hydroxyphenylaminomethyl)-, 2-(p-chlorophenylaminomethyl)-, 2-(p-tolylaminomethyl)- and 2-(naphthylaminomethyl)-8-quinolinol are lower than those of 8-quinolinol. The phenyl substituent in 2 position of oxine moiety exerts an acid strengthening effect on these ligands. The basicity of the ligand N,N′-bis- (8-hydroxy-2-quinolylmethyl)ethylenediamine is higher than that of other oxine derivatives.