bluuebunny/crossref_metadata_2025 huggingface dataset:
The Synthesis and Electrophilic and Nucleophilic Substitution Reactions of 6-Chloro-1-azaazulan-2-ones and 2,6-Dichloro-1-azaazulenes
Authors: Toda Takashi , Seto Shuichi , Nozoe Tetsuo
Published: July 2006

6-Chlorol-azaazulan-2-ones and 2,6-dichloro-1-azaazulenes have been synthesized from 2-amino-5-chlorotropone. By the investigation of their electrophilic and nucleophilic substitution reactions, it is proved that the electrophilic substitutions take place at the C-3 positions of those compounds, and that the nucleophilic substitutions occur at the C-6 positions and then at the C-2 positions. The tautomerism of 6-amino-2-chloro-1-azaazulene derivatives is discussed.
Studies on Separation of Amino Acids and Related Compounds. IV. Separation of Diastereomeric Tripeptides Containing Basic and Acidic Amino Acid Residue
Authors: Muraoka Masako , Yoshida Norio , Noda Kosaku , Izumiya Nobuo
Published: July 2006

Twelve pure tripeptides have been synthesized and the separation of each mixture composed of two diastereomeric tripeptides with an amino acid analyzer has been studied. Among six model systems of diastereomeric mixture studied, a mixture of the Ll and Ld isomers of glycyl-ornithylglutamic acid was separated most efficiently.
Studies on Pyrimidine Derivatives and Related Compounds. LVII. Cyclization Mechanisms of Ethyl 2-(5-Pyrazolyl)aminoalkylidenecyanoacetates
Authors: Takamizawa Akira , Hamashima Yoshio , Sakai Shoji , Nagakura Saburo
Published: July 2006

It was found that the orientation of cyclization reaction of ethyl 2-(5-pyrazolyl)aminomethylenecyanoacetates (Va–c) and ethyl 1-cyano-2-(5-pyrazolyl)aminocrotonates (Xa–c) largely depends on the catalyst used: for example, the cyclization of Va by the acid catalyst results in only 7-amino derivative; on the other hand, the mixture of 7-amino derivative and 7-hydroxy derivative is obtained in the presence of the base catalyst. In order to clarify the mechanism of this reaction, we studied spectrophotometrically the behaviors of these compounds in basic solution, taking ethyl 2-(1,4-dimethylpyrazol-5-yl)aminomethylenecyanoacetate (XV), and ethyl 1-cyano-2-(1,4-dimethylpyrazol-5-yl)aminocrotonate (XVI) as model compounds. Consequently, it was found that the proton dissociation of the C2-amino group is greatly disturbed by the methyl substitution on that carbon atom. This finding is used for explaining the fact that the base catalyzed cyclization of X is insensitive to the amount of catalyst used while that of V shows some dependency on the concentration of alkali.
Effect of Pressure on Graphitization of Carbon. IV. Abrupt Graphitization of Hard Carbon under 5 kbar
Authors: Kamiya Kan-ichi , Inagaki Michio , Mizutani Masato , Noda Tokiti
Published: July 2006

A hard carbon, phenolformaldehyde resin char carbonized to 700°C, was heat-treated under a quasi-hydrostatic pressure of 5 kbar at various temperatures between 1100–1800°C for the residence times of 3, 20 and 60 min. The graphitization process of the hard carbon under pressure consisted of three stages. In the first stage of the graphitization, the profile of (002) diffraction line was symmetrical. It means that there is only one component AH in the sample. In the second and third stages of graphitization, the (002) profile became composite. In the second stage, three components AH, G′H and G″H coexisted in the sample. The sum of the contents of the components G′H and G″H was less than 20% and increased gradually with heat treatment temperature. In the third stage, two components AH and G″H coexisted. The content of the component G″H increased abruptly up to more than 70% at about 1400, 1500 and 1700°C for the residence time of 60, 20 and 3 min, respectively. The components AH and G″H have the turbostratic and graphitic structures, respectively. The component G′H seemed to have the intermediate structure between turbostratic and graphitic structures.
The Use of Carbon Monoxide in Low-temperature Sintering of High-density UO2 Pellets
Authors: Miyazaki Kazuhide
Published: July 2006

The fundamental effects of carbon monoxide on UO2-pellet densification are described. A high density of more than 95% of the theoretical level is attained using carbon monoxide as the sintering atmosphere at a low sintering temperature of 1400°C for laboratory-processed UO2powders. An approximate prediction of the density for any given UO2 powder may be made from the following two experimental criteria: (a) The experimental activation energy for the rate of dissolution of the material into nitric acid may be taken as a measure for the low-temperature sinterability. The density of sintered oxides rises to a maximum at a point where the value of the activation energy for dissolution is about 20 kcal/mol, which is actually very close to the value for the diffusion of oxygen in uranium oxides. (b) The relative intensity of the (220) peak of the X-ray diffraction pattern furnishes another foundation for judging the densification behavior of the UO2 sample.
Solvent Effect in NMR Spectroscopy. II. A Repulsive Interaction between the Benzene Solvent Molecule and the Nitrogen Lone-Pair, and the Effects Induced by the Addition of Protic Substances
Authors: Yonezawa Teijiro , Morishima Isao , Fukuta Kazuhiko
Published: July 2006

The variations in the chemical shifts of proton resonances in imines, aziridines, and oximes, all of which have oriented nitrogen lone-pair electrons, on going from a carbon tetrachloride solution to a benzene solution (“benzene solvent shift”) are determined. Also determined are the changes in the corresponding proton chemical shifts in a benzene solution when protic substances, such as methanol or trifluoroacetic acid, are added (“addition shift”). It is generally found that the upfield benzene-solvent shift is more sensitive to the protons trans to the oriented nitrogen lone-pair than to the cis. This observation indicates that the formation of a benzene-solute collisional complex is most likely to occur at a site as far as possible from the nitrogen lone-pair. The repelling of a benzene solvent molecule by the nitrogen lone-pair may occur due to the repulsive interaction between lone-pair electrons and benzene π-electrons. It is also found that the addition shift is upfield and is larger for the proton trans to the nitrogen lone-pair than for that cis. These general observations are of predictive value in the determination of the orientation of the nitrogen lone-pair electrons and in the assignment of the signals of proton groups in the vicinity of the nitrogen lone-pair.
Fluorescence Quenching and the Charge Transfer in the Excited State. III. Flash Photolytic Studies
Authors: Yamashita Hiroshi , Kokubun Hiroshi , Koizumi Masao
Published: July 2006

It has been established by the flash photolysis that the N,N-dimethyl β-naphthylamine (DMN) cation is produced by the interaction of excited DMN with dimethyl isophthalate (DMP). The assignment has been made by comparing the transient spectrum with that obtained by the γ-radiolysis of DMN in s-butyl chloride. The decay of the DMN cation is first order in acetone (DK, 20.7), ethanol (24.3) DMF (36.7), second order in formamide (109.5) and it is the superposition of first and second order in acetonitrile. This strongly suggests that the radical cation exists as the solvent-shared ion pair in medium polar solvents while as free species in highly polar solvents. The decay of the former has been found to be not essentially affected by oxygen. The finding that the transient spectrum is observed even in the aerated solution supports the view that it is produced at the singlet excited state. From the effect of [DMP] on the yield of triplet DMN, it has been inferred that the radiationless process occurring in the ex-CT complex is mainly internal conversion. The reactivity of the triplet DMN against DMP has been found very small as compared with that of the signlet excited state; the rate constant for (DMN)T+DMP→DMN+DMP was k10\simeq105  m−1 sec−1. The erroneous discussion given in the previous paper has been corrected; the decrease both in the quenching constant (for normal fluorescence) and in the emissivity of the ex-CT emission with the solvent polarity (in slightly polar solvents) is most likely to be attributed to the solvent-solute interaction, the increase of which (with the increase in solvent polarity) is unfavorable both to the formation of the ex-CT complex and to the emissivity of the ex-CT emission.
The Rectification Effects Using the Ices Doped with Electrolytes
Authors: Shimizu Kuniyoshi , Yoshida Yoshiaki , Sen\={o} Manabu , Nozaki Hiroshi
Published: July 2006

The rectifying properties of the combined systems of two crystals, one being doped with a proton donor (poly(styrene sulfonic acid) or hydrogen fluoride) and the other being doped with a proton acceptor (poly(2-vinyl-N-n-butylpyridinium bromide), poly(2-vinyl-N-n-butylpyridinium hydroxide) or lithium hydroxide) are examined and discussed. In the case of the combination of the ices doped with poly(styrene sulfonic acid) and poly(2-vinyl-N-n-butylpyridinium hydroxide) or poly(2-vinyl-N-n-butylpyridinium bromide), the current versus voltage curves have the hysteresis loops and the rectification ratio defined as the ratio of the forward current to the backward current is low. The dynamic rectification effect is slightly observed. In the case of the combination of the ices doped with lithium hydroxide and hydrogen fluoride, the rectification ratios exceed 100 and the rectification mechanism is presumed to be the same as in the system of the aqueous solutions. The dynamic characteristics depend on the frequencies; the rectification phenomena are not observed when the alternating voltages with frequencies higher than 30 kc are applied.
Bond Distances of Cyanogen as Determined by Gas Electron Diffraction
Authors: Morino Yonezo , Kuchitsu Kozo , Hori Yasur\={o} , Tanimoto Mitsutoshi
Published: July 2006

The internuclear distances of cyanogen were determined by gas electron diffraction to be rg(C≡N)=1.1634±0.0019 Å and rg(C–C)=1.3925±0.0022 Å. The average moment of inertia calculated from this structure agreed with Maki’s infrared results as corrected for rotation-vibration interaction. The spectroscopic moment of inertia obtained by Maki was used for calibrating the electron-diffraction scale factor, and the zero-point average distances, with their limits of error, were obtained as rz(C≡N)=1.1552±0.0013 Å and rz(C–C)=1.3871±0.0014 Å.
Stability of Some Bivalent Metal Complexes of Benzoyl-thiobenzoylmethane in Aqueous Dioxane
Authors: Manome Atsushi , Saito Kazuo
Published: July 2006

Concentration equilibrium constants of benzoyl-thiobenzoylmethane (SdbmH) complexes of bivalent magnesium, cobalt, nickel, copper and zinc have been measured in 75% (v/v) aqueous dioxane containing 0.05 m sodium perchlorate. The values for the transition metal ions are greater than those of dibenzoylmethane (dbmH) complexes measured under the same conditions, although the pK value of SdbmH is smaller than that of dbmH. Contribution of dπ–dπ interaction seems to be responsible for such an unusual relationship.
Absorption Spectra and Circular Dichroisms of Metal Complexes. II. Preparation and Structure of Isomers of l-Aminoalcohol Cobalt(III) Complexes
Authors: Ohashi Kousaburo , Fujita Junnosuke , Shimoyama Bun-e , Saito Kazuo
Published: July 2006

Seven new optically active complexes of fac-Δ- and fac-Λ-[Co2(l-armoH)3(l-amo)3]3+ type have been prepared, where l-amoH and l-amo denote l-aminoalcohol and l-aminoalcoholate ion, respectively. The geometrical and the absolute configuration around the metal ion of these complexes have been determined on the basis of their absorption and circular dichroism (CD) spectra. The complexes are monomeric tervalent complex ions in acid solution. In organic solvents and in crystalline states, they seem to have a dimeric structure with face-to-face O···H···O hydrogen bonds between three OH groups of the triprotonated [Co(l-amoH)3]3+ and three oxygen atoms of the deprotonated [Go(l-amo)3]0.
Photo-induced Reactions. XIX. Photopinacolization of Unsymmetric Aromatic Ketones
Authors: Matsuura Teruo , Kitaura Yoshihiko
Published: July 2006

Stereochemistry of the photopinacolization of unsymmetrical aromatic ketones was investigated. In the photopinacolization of aromatic ketones of type PhCOR in isopropyl alcohol, the dl: meso ratio of diastereoisomeric pinacols formed tends to increase as the size of the substituent R becomes bulkier. The dl: meso ratio of pinacols obtained from p-substituted acetophenone, p-X–C6H4–COCH3, is about 1 in the cases that X is H, Cl, and CH3, whereas the ratio is 1.25 in the case of X=OCH3. The photopinacolization of acetophenone in three solvent systems cyclohexane, isopropyl alcohol, and benzene-isopropyl alcohol, was also investigated, and no solvent effect was observed on the dl: meso ratio of acetophenone pinacols.
Sensitization of Photoconductivity. Poly-N-vinylcarbazole with the Copolymerized Dye Molecule
Authors: Okamoto Kenichi , Hasegawa Yo , Kusabayashi Shigekazu , Mikawa Hiroshi
Published: July 2006

The sensitization of the photoconductivity of PVCz by dyes was investigated by the measurement of the characteristics of the decay of the surface charge put on the polymer films. MG was selected as a dye and the following three systems were measured and the degree of the sensitization was compared; i. e., PVCz-MG, copolymer of VGz and VMG and PVCz-PVMG systems. The sensitization was observed in the wavelength region from 300 to 1200 mμ. Sensitization in the visible region was larger than in the ultraviolet. The copolymer system was inferior to the PVGz-MG system, probably because of the large loss of the carriers by the recombination and trapping in the bulk. There was the optimum concentration of the dyecontent, probably because of the disturbing effect of the dye molecule for the migration of the carriers. To make sure this point, the inhomogeneous films with the dye only on the surface were investigated. The results were explained by the difference in the distiribution of the centers of carrier generation and those of recombination and trapping of the carriers in the bulk.
Formation and Decay of the Transient Species in Radiation Chemistry. Radiolysis of Alkyl Halide Systems
Authors: Ueda Hisashi
Published: July 2006

Biphenyl and trans-stilbene were irradiated by a pulse of 300 mA×0.5 μsec in two types of solvents, alkyl halides and methyltetrahydrofuran. The spectra obtained by n-butylchloride, 1,1-dichloroethane, 1,2-dichloroethane, 1,1,2-trichloroethane, and 1,1,2,2-tetrachloroethane were concluded to be those of the cations, while the spectra obtained by CCl4, 1,1,1-trichloroethane, and pentachloroethane were concluded to be due to something other than the cations. The spectra of o-terphenyl in 1,1,2-trichloroethane and in 2-methyltetrahydrofuran were different, the reason for this was discussed. The decay curves of the optical densities due to both the cations and the anions all exhibited first-order rates. The decay of the cation of the aromatic solute was concluded to consist of two processes, the transportation of the charged species and the neutralization of the ion pair thus formed. The rate-determining step is the neutralization process, the activation energies of which are 2.17 and 3.62 kcal/mol for trans-stilbene and biphenyl respectively. The transportation of the charged species was concluded to be not by the movements of the anion and the cation across the solution, but by the electron-trap- and hole-conductions, such as have been observed in semiconductors.
Calorimetric Study of the Glassy State. IV. Heat Capacities of Glassy Water and Cubic Ice
Authors: Sugisaki Masayasu , Suga Hiroshi , Seki Syûzô
Published: July 2006

By making use of the vapor-condensation type calorimeter, the heat capacity measurements of amorphous, cubic and hexagonal ices were made between 20°K and 250°K. The glass transition phenomenon was found near 135°K with the sudden change of the heat capacity amounting to 35 J/(mol°K). The drastic crystallization with the exothermic effect which amounts to 1.64 kJ/mol was then followed at this temperature. The transformation of the cubic crystal to the hexagonal one was confirmed to occur in the temperature region from 160 to 210°K and to proceed in two steps with the activation energies of 21.3 and 44.7 kJ/mol, respectively. The amount of the exothermic effect accompanying this transformation was found to be about 160 J/mol.
The Fluorescence Spectrum of Benzene in Solution at 77°K
Authors: Murakami Yoshio , Kanda Yoshiya
Published: July 2006

The fluorescence spectrum of benzene in methylcyclohexane at 77°K has been analyzed in detail. The forbidden 0–0 band appeared weakly, and all the bands were interpreted as allowed bands except for the 0–992 band. The fluorescence spectrum has also been studied in carbon tetrachloride; the anomalous vibrational structure has been found in solutions as dilute as 10−3  m, irrespective of the cooling procedure. The correlation with the absorption and with the phosphorescence spectrum of benzene reported previously has been discussed.
Episulfones. IV. The Decomposition Reaction of Episulfones by Bases
Authors: Matsumura Shoichi , Nagai Toshikazu , Tokura Niichiro
Published: July 2006

The present paper deals with the decomposition reaction of episulfones in the presence of several bases. The treatment of cis-stilbene episulfone (I) with 2 n NaOH gave trans-stilbene in a 92% yield, and a hydrogen-deuterium exchange experiment using NaOD showed that 66% of the methine protons of the episulfone were exchanged. On the other hand, the reaction of n-butyllithium yielded cis-stilbene predominantly, along with trans-1,2-diphenylvinyl sulfinate in about a 20% yield. Styrene episulfone (II) gave styrene (80%) and a trace of benzyl methyl sulfone when II was treated with alkali. Tetraphenylethylene episulfone (III) afforded tetraphenylethylene almost quantitatively. The cleavage mechanism by bases is then discussed on the basis of the above results. Ethylene episulfone (IV) is oligomerized by tertiary-amine catalysis.
The Absolute Configuration of Pinocarvone Oxide
Authors: Katsuhara Jun
Published: July 2006

The conversion of (−)-pinocarvone oxide derived from (+)-pinocarvone into (−)-(1R:2S:3R:5R)-cis-2-hydroxypinocampheol and the conversion of (+)-pinocarvone oxide in (+)-(1R:2R:3R:5R)-trans-2-hydroxyneoisopinocampheol and (−)-(1R:2R:3R:5R)-cis-2-hydroxyisopinocampheol are described. With the knowledge of the absolute configurations of these glycols, it was concluded that (−)-pinocarvone oxide and (+)-pinocarvone oxide have the (1R:2S:5R)- and (1R:2R:5R)-configurations, respectively.
A Study of the Charge-Transfer Complexes. V. The Complexes of Tetracyanoethylene with trans-Stilbene and Related Compounds
Authors: Matsuo Taku , Aiga Hiroshi
Published: July 2006

The charge-transfer (CT) absorptions of complexes of tetracyanoethylene with trans-stiibene and related compounds were measured both in solution and in solid media. The first and the second CT bands were found to be affected differently by the substituents on the donor molecule; thereupon they were assigned to the transitions of an electron from, respectively, the highest occupied and the second highest occupied orbitals of the donor to the lowest unoccupied orbital of the acceptor. Both the location and the intensity of the first CT band were found to be extremely sensitive to variation in media and temperature. The explanation was arrived at by the use of a model where an acceptor molecule was assumed to associate independently with several different sites of a donor molecule.
Photochemical Hydrolysis of Barbitals
Authors: Otsuji Yoshio , Kuroda Tokuyuki , Imoto Eiji
Published: July 2006

The irradiation of barbital (BA) and N,N′-dimethylbarbital (DMBA) in aqueous alkaline media gave diethylacetylurea and N,N′-dimethyldiethylmalonarmide respectively. On the basis of the results of kinetic studies, the above photochemical hydrolyses of BA and DMBA were shown to be an attack of the hydroxide ion on the singlet excited states of BA monoanion and DMBA respectively. Such nucleophilic reagents as amines, mercaptide, and cyanide ions retarded the photochemical hydrolyses by quenching the excited state of the substrates.
New Syntheses of Vinyl Sulfides and Unsaturated Nitriles via Quaternary Phosphonium Salts
Authors: Kumamoto Takanobu , Hosoi Kazuo , Mukaiyama Teruaki
Published: July 2006

New methods for the syntheses of vinyl sulfides and unsaturated nitriles via quaternary phosphonium salts have been established. The reaction of isopropylidenetriphenylphosphorane with S-ethyl thiobenzoate or substituted S-ethyl thiobenzoates afforded vinyl sulfides and triphenylphosphine oxide in good yields. Further, it was found that the reaction of α-benzoylalkylphosphonium salts with sodium ethylmercaptide or potassium cyanide gave olefins, such as vinyl sulfides or unsaturated nitriles, and triphenylphosphine oxide in good yields, respectively.
Studies of Aminosugars. XIX. Syntheses of O-Benzyl-α-halogeno Derivatives of 3-Acetamido-3-deoxy- and 6-Acetamido-6-deoxy-d-glucose
Authors: Koto Shinkiti , Tsumura Takayuki , Kato Yoshinori , Umezawa Sumio
Published: July 2006

As a part of investigation of the synthesis and reaction of 1-halogeno derivatives of amino-monosaccharides, 3-acetamido-2,4,6-tri-O-benzyl-3-deoxy-α-d-glucopyranosyl chloride and 2,3,4-tri-O-benzyl-6-(N-benzylacetamido)-6-deoxy-α-d-glucopyranosyl chloride have been synthesized. Attempts to prepare α-glycosides from these benzyl derivatives proved to be practical, giving cyclohexyl 3-acetamido-2,4,6-tri-O-benzyl-3-deoxy-α-d-glucopyranoside and cyclohexyl 2,3,4-tri-O-benzyl-6-(N-benzylacetamido)-6-deoxy-α-d-glucopyranoside as main products. Removal of the masking groups gave cyclohexyl α-glucosides of 3-amino-3-deoxy-d- and 6-amino-6-deoxy-d-glucose respectively. A number of related derivatives have been described.
Studies of Aminosugars. XX. The Synthesis of 6-O-(3-Amino-3-deoxy-α-d-glucopyranosyl)-2-deoxystreptamine
Authors: Koto Shinkiti , Tatsuta Kuniaki , Kitazawa Eiichi , Umezawa Sumio
Published: July 2006

6-O-(3-Amino-3-deoxy-α-d-glucopyranosyl)-2-deoxystreptamine (3AD) which is a glycoside component of kanamycin A has been synthesized. Amino and hydroxyl groups of 2-deoxystreptamine were masked with carbobenzoxy and isopropylidene groups to give racemic mono-O-isopropylidene-di-N,N′-carbobenzoxy-2-deoxystreptamine with which 3-acetamido-2,4,6-tri-O-benzyl-3-deoxy-α-d-glucopyranosyl chloride was condensed by a modified Koenigs-Knorr reaction. Removal of all the masking groups followed by N-dinitrophenylation, acetylation and chromatography gave the product identical with an authentic specimen of the penta-O-acetyl-tri-N-(2,4-dinitrophenyl) derivative of the natural 3AD. The synthetic product was further led to 3AD identical with a natural sample.
Oxidation of Propylene over the Tin-Antimony Oxide Catalysts. II. Investigations of Physicochemical Properties of the Catalysts
Authors: Wakabayashi Katsuhiko , Kamiya Yoshio , Ohta Nobuto
Published: July 2006

The physicochemical properties of the binary system composed of Sn and Sb oxides have been investigated. The electrical conductivity increased rapidly up to 3 atom% Sb, and subsequently decreased, little by little, as the Sb oxide content in the binary system increased. The surface area also increased rapidly up to 3 atom% Sb, and in the region exceeding this content a dilution effect due to Sb oxide was observed. The behavior of the initial rate of acrolein formation as a function of the catalyst composition was fairly similar to that of the surface area. The apparent activation energies for carbon dioxide formation at first decreased, and then became nearly constant when the Sb content of the catalysts increased. On the other hand, the activation energies for acrolein formation may be considered to be always constant, independent of the catalyst composition, at about 17 kcal/mol. The activation energies for the catalyst reduction by hydrogen were 28 kcal/mol for Sn oxide, 14 for a mixture containing 25 atom% Sb, and 30 for Sb oxide. Consequently, it has been concluded from these results that it may depend on the nature of the chemisorbed oxygen which attacks propylene whether the propylene is oxidized into acrolein or into such complete combustion products as carbon dioxide.
Effect of Pressure on Graphitization of Carbon. V. Electron Spin Resonance in Hard Carbon Heat-Treated under High Pressure
Authors: Kamiya Kan-ichi , Yugo Shigemi , Inagaki Michio , Saito Hajime , Tsuzuku Takuro
Published: July 2006

By means of the electron spin resonance (ESR), the graphitization process of a hard carbon (phenolformaldehyde resin char) under a pressure of 5 kbar was investigated in relation to the results of the X-ray diffraction analysis. In the ESR measurement, there is observed only a sharp Lorentzian line having g-value of about 2.003 for the products heat-treated at relatively low temperatures. On the other hand, gradual increase in the heat treatment temperature (HTT) leads to the appearance of new 15–20 G wide line having g-value of about 2.01, overlapping on the sharp one, and its absorption intensity tends to increase further with HTT. The appearance of the broad ESR line has been found always being accompanied by an abrupt increase of the content of graphitic component deduced from the analysis of (002) diffraction profile. From further investigation of features of these ESR lines as a function of ambient temperature, the sharp one is concluded that it originates from the so-called localized spin centers, while the broad one from the delocalized. The coexistence of these two signals suggests that the turbostratic and graphitic parts have enough extent to prevent the motional mixing of these spin centers, which has also been verified by the X-ray diffraction analysis.
An Oxygen Concentration Profile of a MnO2 Particle after Discharge Service
Authors: Miyazaki Kazuhide
Published: July 2006

The behavior of oxygen in a manganese dioxide depolarizer discharged in a Leclanche-type test cell down to a cut-off voltage of 0.7 V was visually examined by means of electron probe microanalysis. The oxygen concentration profile of a typical MnO2 particle of about 50 μ in diameter showed that the relative amount of oxygen at the surface and along the pores inside was evidently reduced due to the discharge reaction invading 5 to 10 μ towards the inner part of the particle, indicating that the discharge primarily took place in these portions and involves a process of releasing oxygen from sites at the outermost surface and along the pores. The region which contains these lower oxide portions was observed to be 20–30% of the total crosssectional area, implying that the utility factor of MnO2 as a depolarizer was accordingly of the order of 20–30%. It was suggested that enhancement of the use of pores or cleavages during a discharge would generally be beneficial to the service life as a depolarizer, better than merely reducing the particle size of the material.
Rate of Electron Exchange between Cuprous and Cupric Ions in Concentrated HCl by Electron Spin Resonance
Authors: Stewart R Allan , Reeves L W , Fujiwara Shizuo
Published: July 2006

Contrary to previous reports, the linewidth of the electron spin resonance spectrum of cupric ion as measured in gauss between points of maximum slope is a sensitive function of ionic strength, chloride ion concentration and cuprous ion concentration. Assuming that electron spin relaxation rates do not change greatly on the addition of cuprous ion, it is possible to derive an electron exchange rate for the reaction:

Cu^++Cu^2+↔Cu^2++Cu^+

of k=1.53×109  l/mol/sec. This value is in good agreement with a previous determination of the same rate constant by McConnell and Weaver using the 63Cu nuclear magnetic resonance (0.5×108). The results for the linewidth changes can be rationalized in all cases by assuming that bridge chloride ions between two cupric ions or one cupric and one cuprous ion change drastically in concentration as such factors as ionic strength or chloride ion concentration changes. The g value of the electron (free) decreases as chloride ion is added, indicating delocalization of the unpaired electron onto chloride ligands.
A Study on the Electronic Spectra of 1-(p-Substituted phenyl)pyrroles
Authors: Matsuo Taku , Shosenji Hideto , Miyamoto Reiji
Published: July 2006

The longest wavelength electronic absorption band of 1-(p-substituted phenyl)pyrrole has been found to show a regular bathochromic shift as the electronegativity of the substituent on the phenyl group increases. The substituent effect is closely related to that for the intramolecular charge-transfer bands of p-substituted anilines. Therefore, the longest wavelength absorption band of 1-(p-substituted phenyl)pyrroles have been suggested to be originated from an electron transfer from the pyrryl group to the phenyl group. Only one exception is the spectra of 1-(N,N-dimethyl-p-aminophenyl)pyrrole. In this case, the longest wavelength electronic absorption band is suggested to be due to an electron-transfer from the N,N-dimethylamino group to the phenyl group.
Radiolysis of Methylcyclohexane. I. Effects of Temperature and Electron Scavengers on Hydrogen Formation
Authors: Kimura Toyoaki , Miyazaki Tetsuo , Fueki Kenji , Kuri Zen-ichiro
Published: July 2006

The effects of temperature and electron scavengers on the hydrogen yield in the radiolysis of methylcyclohexane have been investigated by conventional kinetic techniques. The I value for hydrogen formation from pure methylcyclohexane varied from 4.9 to 4.4 in the range from room temperature to liquid nitrogen temperature. In the iodobenzene-methylcyclohexane system, the decrease in hydrogen yield was equal to the yield of benzene produced within experimental error. It is concluded that the benzene is formed through H atom abstraction from the solvent molecules by phenyl radicals which are formed by dissociative electron attachment to iodobenzene and that the benzene yield indicates the scavenged electron yield. Furthermore, a kinetic treatment for electron scavenging in the glassy state was presented. In the N2O-methylcyclohexane system, it was found that the ratio of the nitrogen yield, G(N2), to the decrease in hydrogen yield, ΔG(H2), is 2 in the temperature range from room temperature to −140°C, 1 at −160°C, and increases from 1 to 4 with increasing N2O concentration at −196°C, respectively.
γ-Radiolysis of a Binary Mixture of Methanol and Water. The Formation of Formaldehyde in the Radiolysis of Liquid Methanol
Authors: Seki Hiroshi , Nagai Reiko , Imamura Masashi
Published: July 2006

The γ radiolysis of a binary mixture of methanol and water over a wide concentration range has been investigated. The observed yields of products are expressed as a linear function of the electron fraction of methanol in the mixture. The yields of molecular hydrogen were also determined. Analyzing the results on reasonable assumptions, one could obtain for neutral water, Ge\barsw=2.3–2.5 and GOHw≥2.6. It was concluded that, in the radiolysis of methanol, formaldehyde may be produced through the decomposition of CH2OH radicals in the spur region, not by the disproportionation of these radicals.
Phase Changes in the ZrO2-TiO2 System
Authors: Noguchi Tetsuo , Mizuno Masao
Published: July 2006

The liquidus curve in the ZrO2-TiO2 system previously reported by the present authors was again examined with a heliostat-type solar furnace in order to determine the peritectic point in the ZrO2-rich side region. Quenched specimens from the melt of the ZrO2-rich side region were analysed by the X-ray technique. The cooling curves from the melt suggested the existence of a new phase stable at higher temperatures, and a tentative phase diagram at high temperatures is presented.
Ca3(PO4)2 - CaNaPO4 System
Authors: Ando Jumpei , Matsuno Seiichi
Published: July 2006

As a fundamental research of a calcined defluorinated phosphate containing a small amount of sodium, the system Ca3(PO4)2(tricalcium phosphate, T) - CaNaPO4(Rhenanite, R) was studied by high temperature X-ray diffraction, differential thermal analysis, etc., and the phase diagram determined. During heating, T inverted from β to α at 1180°C, and then possibly from α to α′ at 1280°C. R inverted from β to α at 690°C. In the composition range containing R from about 10 to 98% by weight, (βT+βR), the stable phase at room temperature, inverted to (βT+αR) at 650°C. The (βT+αR) changed at 980°C to form a compound “A” Ca5Na2(PO4)4 for the sample containing 50.5% R, and (“A”+βT) for samples containing a smaller amount of R. The (“A”+βT) then changed to “A” solid solution at elevated temperatures. The crystals of “A” consisted of a superlattice of αR. “A” and the solid solution changed to αR solid solution at higher temperature. By quenching the samples containing 35 to 50.5% R from 1400°C, a single phase “A” or “A” solid solution was obtained at room temperature. The “A” solid solution was the major phase of the calcined defluorinated phosphate. During heating of samples containing more than 50.5% R, (βT+αR) changed to αR solid solution at or below 980°C; during cooling of the solid solution (“A”+βR) formed at 650°C.
Electronic Structure of Tris(α-diimine)iron(II) Complexes
Authors: Ito Tasuku , Tanaka Nobuyuki , Hanazaki Ichiro , Nagakura Saburo
Published: July 2006

The electronic structures of tris(α-diimine)iron(II) complexes have been investigated. The theoretical consideration has revealed that a considerable π-back donation takes place in the ground state and as a result unusually stable complexes of iron(II) are formed. The intense band which appears in the visible region has been proved to be due to the charge transfer transition from 3dπ AO (atomic orbital) of iron to the lowest vacant π MO (molecular orbital) of the ligand α-diimine. It was found both theoretically and experimentally that the π→π* transition with the lowest energy in α-diimine is polarized parallel to the nitrogen-nitrogen direction of the molecule, and that transition dipoles in the three ligands of tris(α-diimine)iron(II) ion interact to give resultant A1→A2 and A1→E transitions in the metal complex with D3 symmetry. Details of the electronic structures, including the splitting energy and the intensity of the local excitation in α-diimine molecule and the nature of the charge transfer band, have been discussed.
Studies on Separation of Amino Acids and Related Compounds. III. Separation of Diastereomers of Leucyl Dipeptides by Ion-Exchange Chromatography
Authors: Noda Kosaku , Okai Hideo , Kato Tetsuo , Izumiya Nobuo
Published: July 2006

A series of experiments on a column chromatography of Dowex 50 with ammonium acetate solvent systems as eluent was carried out in order to find optimal conditions for the separation of the diastereomers of leucylalanine, leucylvaline, leucylleucine and leucyltyrosine. The effects of pH concentration of the salt and alcohols in the solvent systems for the separation of the diastereomers were studied. Among many conditions tested, the change of pH in the solvent system afforded most remarkable influence for the separation; the order of elution of the diastereomers of the dipeptide was found to be inverted at near pH 5.0. On a preparative scale l-leucyl-Dl-valine was successfully separated into the two diastereomers by using a fairly large column. Attempt to separate benzyloxycarbonyl-l-leucyl-Dl-valine benzyl ester with a column of Sephadex LH-20 was described, also.
Coumarins. IV. The Acid-catalyzed Reaction of Phenols with Allyl Cyanide
Authors: Amakasu Takeshi
Published: July 2006

A new route to the syntheses of 4-methyldihydrocoumarins has been developed by means of the aluminum chloride-catalyzed reaction of phenols with allyl cyanide. The reaction of excess phenol with allyl cyanide in the presence of 2 equivalents of anhydrous aluminum chloride and an excess of hydrogen chloride yielded β-(p-hydroxyphenyl)-butyronitrile in a 16% yield. In contrast, the corresponding 4-methyldihydrocoumarins were obtained, together with β-arylbutyronitriles, from o- and m-cresols. p-Cresol gave rise to 4,6-dimethyldihydrocoumarin as the sole product in a 8% yield. In diisopropyl ether, resorcinol underwent a similar reaction with allyl cyanide and afforded 4-methyldihydroumbelliferone in a 50% yield.
Oxidation of Phosphites by Means of p-Quinones and Benzyl Alcohol
Authors: Mitsunobu Oyo , Kodera Kyoko , Mukaiyama Teruaki
Published: July 2006

Triethyl phosphite and tri-n-butyl phosphite were oxidized to the corresponding trialkyl phosphates by means of p-quinones and benzyl alcohol. On the other hand, when diethyl (N-diethyl)phosphoroamidite was treated with p-benzoquinone and benzyl alcohol, 4-ethoxyphenyl ethyl (N-diethyl)phosphoroamidate was obtained in a 69% yield and no diethyl (N-diethyl)-phosphoroamidate was isolated. The reaction of 2,3,5,6-tetrachloroquinone with diethyl benzyl phosphite in the presence of ethanol resulted in the formation of triethyl phosphate and 4-benzyloxy-2,3,5,6-tetrachlorophenyl diethyl phosphate in 16% and 68% yields respectively.
Photolysis of Nitrite Esters bearing Nitrogen on the β-Carbon
Authors: Suginome Hiroshi , Murakami Masakazu , Masamune Tadashi
Published: July 2006

The results of photolysis of a number of nitrite esters derived from jervine, in which the respective β-carbon of nitrite group bears nitrogen, are described. It has been found that in these nitrites when a nitrogen on β-carbon was in the amide group, the irradiation caused the cleavage of α, β-single bond to the nitrite group. The reaction is exemplified by photolysis of 3O, N-diacetyl-22,27-imino-11-oxojerva-5,13(17)-diene-3β, 23β-diol 23-nitrite ester (Ic) to afford an aldehyde II. When a nitrogen on β-carbon of nitrite was tertiary (e.g., XIb), however, no photoinduced fission of carbon-carbon bond in these nitrites was observed and the starting alcohol recovered unchanged. These results coupled with others, e.g., the result of photolysis of 3O-acetyl-N-benzoyl-22,27-imino-11-oxojerva-5,12-diene-3β, 23β-diol 23-nitrite ester (IIIf) indicate the selective cleavage of acyl-nitrogen bond followed by acidic hydrolysis to an aldehyde during chromatography, as shown in the scheme V to VIII. It is noted that this reaction is contrasted with the reported results with regard to photolysis of nitrites bearing oxygen in place of nitrogen.
Analyses of Organic Soils Extracted from Naturally-soiled Cloths
Authors: Tsunoda Teruo
Published: July 2006

The analyses of organic soils extracted from naturally-soiled chloths were carried out by IR spectroscopy, gas chromatography, thin-layer chromatography (TLC), and gel filtration. The fatty-acid constituents involved in organic soil were determined by gas chromatography. The presence of triglycerides, cholesterol and its ester, and such hydrocarbons as paraffin and squalene in organic soil was also found by means of TLC. In gel filtration, two peaks were found in elution diagrams of the detergent solution after washing naturally-soiled cloths. The ultraviolet spectra, which were measured for the effluent corresponding to each peak, indicated that the nitrogen compound involved in each effluent is probably a protein-lipid complex such as lipoprotein. The nitrogen content in each effluent was also determined by the micro-Kjeldahl method. A smaller nitrogen content was given for the effluent corresponding to the first peak than for that of the second peak. The nitrogen compound involved in the effluent for the first peak was harder to remove from cloths than that for the second peak.
Thermal Decomposition of Ketene in Shock Waves
Authors: Tsuda Morizo , Kuratani Kenji
Published: July 2006

With the use of a single pulse shock tube of a magic hole type, the thermal decomposition of ketene was studied at temperatures from 1140 to 1530°K. The formation of carbon monoxide, that is, the disappearance of ketene, followed a kinetic order of 1.5 with respect to ketene and its rate constant was represented by

k=10^14.2exp[(-65600±1100)/RT]l^1/2mol^-1/2sec^-1.

The thermal decomposition of mixtures of ketene and ethylene in argon was also studied, and the formation of methylene radicals during the pyrolysis of ketene is deduced from the presence of propylene and cyclo-propane in the products of these three component reactants. The rate of ketene disappearance was not affected by the addition of ethylene, or nitric oxide. A chain mechanism in which methylene radicals play a principal part, and a combined molecular mechanism of first, and second orders were proposed tentatively to explain the observed 1.5th order reaction rate.
Adsorption Behavior of Hydrogen and Carbon Monoxide over Zinc Oxide in the Mixed Gas Adsorption and during the Methanol Decomposition Reaction
Authors: Tsuchiya Susumu , Shiba Tadao
Published: July 2006

Adsorption of hydrogen and carbon monoxide at the different situations has been investigated with zinc oxide which is the principal component of ordinary methanol synthesis catalysts. In the simultaneous adsorption of hydrogen and carbon monoxide the mutual interaction was also observed. The results were explained as the displacement effect as well as the enhancement took place in a certain region of the partial pressures. Adsorption measurements during the decomposition reaction suggest that in initial state the adsorbed species are mostly the adsorbed methanol and that the step of the decomposition of it is the rate-determining step of the overall reaction. The mechanism of methanol synthesis over zinc oxide is suggested to proceed in the similar way as on the three component catalyst previously used.
On the Glass Transition Phenomenon of Isopentane
Authors: Sugisaki Masayasu , Adachi Keiichiro , Suga Hiroshi , Seki Syûzô
Published: July 2006

Heat capacity measurement of isopentane was carried out for crystalline, liquid, glassy, and supercooled liquid states in the temperature region between 13 and 300°K. The glass transition phenomenon of isopentane was found around 65°K with drastic heat capacity change of 68.20 J/mol degK. This glass transition phenomenon is tentatively interpreted in terms of the Adam and Gibbs theory. The value of Tg⁄T2, the ratio of glass transition temperature Tg, and the temperature of disappearance of the configurational entropy of the supercooled liquid T2, for isopentane was found to be 1.30 which is concordant with the value cited by Adam and Gibbs. The residual entropy at absolute zero of the glassy isopentane was shown to be 14.06 J/mol degK. In addition the irreversible production of entropy during the glass transition intervals was found to be 0.08 J/mol degK. It is concluded that the neglect of the irreversible production of entropy leads no significant error in determing the residual entropy.
Episulfones. III. Reductive Cleavage of Episulfones by Complex Metal Hydrides
Authors: Matsumura Shoichi , Nagai Toshikazu , Tokura Niichiro
Published: July 2006

The reduction of cis-stilbene episulfone (I) by such a complex metal hydride as lithium borohydride, sodium borohydride, or lithium aluminum hydride gave dibenzylsulfone (V) selectively as a result of the unusual cleavage of the carbon-carbon single bond. Comparing the difference between lithium aluminum hydride and lithium borohydride or sodium borohydride in various solvent systems, we suggest that particular solvent effects are operating in the present reaction. The reduction of I with lithium aluminum hydride resulted in a low yield (0–10%) of V, while the reduction with lithium borohydride afforded V in a 45% yield. The reduction of styrene episulfone (II) gave no carbon-carbon cleavage product, but it did give a carbon-sulfur fission product, yielding sulfinic acid salt (VIII). The formation of VIII is interesting compared with the reduction of styrene oxide by lithium aluminum hydride. Tetraphenylethylene episulfone (III) produced a carbon-carbon cleavage product, 1, 1, 3, 3-tetraphenyl dimethyl sulfone (XI), in a 68% yield. A reaction mechanism for the reductive cleavage reaction has been proposed on the basis of the above-mentioned results. In addition, we observed that diborane was evolved by the reaction of sulfur dioxide with lithium- or sodium borohydrides.
The Autoxidation of Toluene Catalyzed with Cobalt Monobromide in Acetic Acid
Authors: Sakota Koichiro , Kamiya Yoshio , Ohta Nobuto
Published: July 2006

The kinetics of cobalt-catalyzed autoxidation of toluene have been studied in acetic acid in the presence of sodium bromide. The reaction is found to proceed of apparent zero-order in the concentration of toluene for a long duration and of first-order in its initial concentration and of second-order in cobalt ion concentration. In case of ethylbenzene or cumene the rate of oxidation is of first-order in its concentration. This zero-order dependence is explained as a result of the co-oxidation of toluene and its intermediate reaction product, benzaldehyde. A reaction scheme is proposed, which has been shown to be consistent with experimental data by solving out the rate equations simultaneously with a computer, co-oxidation of toluene and benzaldehyde being taken into consideration.
Concurrent Oxygen Exchange and Racemization Reactions of Diaryl Sulfoxides in Concentrated Sulfuric Acid
Authors: Oae Shigeru , Kunieda Norio
Published: July 2006

When diaryl sulfoxides are dissolved in concentrated sulfuric acid at 0°C, characteristic bluish colored solutions are obtained, from which the starting sulfoxides can be recovered quantitatively upon quenching with a large amount of water. When 18O-labeled and optically active sulfoxides are used, one observes the concurrent oxygen exchange and racemization reactions of the sulfoxides. The kinetic behaviors of these reactions have been studied in detail using various substituted diaryl sulfoxides. The rate of the oxygen exchange was found to be identical to that of the racemization while the rates of the racemization were nicely correlated with the Hammett acidity functions (H0) (Slope=1.07). Meanwhile the polar effect of subsituents on the rates of both oxygen exchange and racemization was found to be very small. From these results possible mechanisms for these reactions have been discussed.
The Structure-Stability Relationship of the Metal Ion Complexes of Unsaturated Compounds. III. The Effects of Polar Substituents on the Silver Ion - Olefin Complexation
Authors: Fueno Takayuki , Kajimoto Okitsugu , Furukawa Junji
Published: July 2006

The equilibrium constants for the formation of silver ion complexes of various vinyl compounds in water were determined at 25°C by the distribution method. It has been found that the equilibrium constants obtained are closely related to the Hammett sigma meta values of the relevant substituents, the reaction constant being ρ=−5.07 with the correlation coefficient r=0.974. The results have been interpreted in terms of the inductive effect of the substituents as the most dominant contribution to the stabilities of these complexes.
The Structure-Stability Relationship of the Metal Ion Complexes of Unsaturated Compounds. IV. Argentation Equilibria of Alkenyl Alkyl Ethers
Authors: Fueno Takayuki , Kajimoto Okitsugu , Okuyama Tadashi , Furukawa Junji
Published: July 2006

The equilibrium constants, K, for the formation of 1 : 1 Ag+ - alkenyl alkyl ether complexes were measured in the temperature range 10 to 30°C by the gas chromatographic method. It has been found (1) that cis isomers have the values of K several times greater than those of the corresponding trans isomers, (2) that the K-value tends to diminish with the increasing degree of β-substitutions, (3) that, in a series of cis ethers, K increases as the β-alkyl substituent becomes bulkier, and (4) that the variation of the alkoxy groups causes little change in the K-value. The difference in the K-values between the cis and trans complexes is found to be ascribable mainly to their difference in the enthalpy changes, ΔH, accompanying the complexation. These trends have been discussed on a thermodynamic ground in comparison with those already noted for olefins.