bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cationic Effect on the Polarographic Reduction of Nickel(II) in Acetonitrile
Authors: Ikeda Shigero , Itabashi Eiki 
Published: July 2006

Abstract
The polarographie behavior of nickel(II) acetate salts dissolved in acetonitrile solvent containing small quantities of acetic acid has been investigated in various natures and concentrations of supporting electrolytes. A single reduction wave is observed in the solutions of lithium perchlorate or sodium perchlorate. The limiting current has an intermediate nature of both diffusion- and kinetic controlled polarographic current. A double wave, on the other hand, is observed in the solutions of tetraalkylammonium perchlorate supporting electrolyte such as (CH3)4NClO4, (C2H5)4NClO4 or (n-C4H9)4NClO4. The limiting current of the first step exhibits an intermediate nature of both diffusion and kinetic currents, and that of the second step is kinetic in nature. The effect of the nature and concentration of electrolyte on the visible absorption spectra of acetatonickel(II) complexes in acetonitrile containing small quantities of acetic acid are also discussed. On the basis of evidence, a mechanism which involves a substitution reaction of acetatonickel(II) complexes with the supporting electrolytes is proposed. The substitution reaction in tetraalkylammonium perchlorate solutions is thought to be the rate-determining step. The first step of a double wave is also thought to be due to the inhibition of charge transfer process by the weakly absorption of tetraalkylammonium cations of supporting electrolytes on the DME.
Organic Syntheses by Means of Noble Metal Compounds. XXXVII. Carbonylation of Allene-Palladium Chloride Complexes
Authors: Susuki Tosaku , Tsuji Jiro 
Published: July 2006

Abstract
The reaction of allene with palladium chloride and a carboxylate anion gave di-μ-chloro-bis(2-acyloxy-π-allyl) dipalladium which was converted into an acetoacetate by carbonylation. Carbonylation of allene in ethanol in the presence of palladium chloride produced ethyl itaconate. The carbonylation of di-μ-chloro-bis(2-chloro-π-allyl) dipalladium in ethanol formed 3-chloro-3-butenoate. 4-Hydroxy-3,4-dimethyl-2-pentenoic acid γ-lactone, 3-isopropylideneglutarate and 3-(ethoxycarbonylmethyl)-4-methyl-3-hexenedioate were isolated by the carbonylation of di-μ-chloro-bis[2-(1-(chloromethyl)vinyl)-π-allyl] dipalladium. The mechanisms of these reactions are discussed.
Hydrogen Produced by the Hot-Atom-Process in the Radiolysis of Ethane
Authors: Inoue Masao , Uno Taiko , Sato Shin , Shida Shoji 
Published: July 2006

Abstract
The mechanism of the formation of “molecular” hydrogen in the ethane radiolysis at 300 Torr has been studied with ethane-ethane-d6-ethylene mixtures. The G-value of the hydrogen has been found to be 3.3. The addition of electron and positive ion scavengers scarcely affected the formation of the hydrogen at all. From the isotopic composition of the hydrogen, it was demonstrated that most of the hydrogen is formed by molecular detachment from the ethane molecule, while the rest is formed by the abstraction of a hydrogen atom from the ethane molecule by a hot hydrogen atom, the G-value being estimated to be 0.6.
Syntheses of trans-Isoflavan-4-ols
Authors: Yamaguchi Shozo , Ito Shoei , Suzuki Ikuko , Inoue Naoto 
Published: July 2006

Abstract
The reaction of nitrous acid and three 4-aminoisoflavan hydrochlorides (III, IV, and V) obtained by the catalytic hydrogenation of isoflavanone oximes, and the hydroboration of three isoflavenes (XII, XIII, and VIII), were investigated in the hope of finding a general method of synthesizing trans-isoflavan-4-ols. The reaction of III and IV with nitrous acid afforded the corresponding trans-4-ols, though in a poor yield, but that of V produced no expected compound, the corresponding isoflavene (VIII) being obtained instead. The hydroboration of XII, XIII, and VIII afforded the corresponding trans alcohols (VI, VII, and XIV) in good yields. In addition, it became clear that 4-aminoisoflavans obtained by the catalytic reduction of the oximino compounds possess the 3,4-cis configuration.
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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.