bluuebunny/crossref_metadata_2025_split huggingface dataset:
Metallic Impurity-Activated Crystal Growth of Boron Phosphide by Chemical Vapor Deposition and Its Physical Properties
Authors: Motojima Seiji , Miura Yasuo , Sugiyama Kohzo , Takahashi Yasutaka 
Published: July 2006

Abstract
Needle single crystals of boron monophosphide as large as 5–100 μm in diameter and 4 mm in length were obtained by chemical vapor deposition on an impurity painted zone of quartz substrate at 1060–1120 °C. The impurities such as Mn, Ni, Pt, Ag or Au were painted on the substrate in a form of aqueous solution of their salts and decomposed or reduced to the respective metal in hydrogen atmosphere at 1000 °C. Needle crystals with the homo p-n junction were also prepared using Ni impurity. The colors of grown crystals varied with the change of gas composition. Differences of electrical resistivity and thermoelectric power were found between the crystals of different colors.
An NMR and Mössbauer Spectroscopic Study of Mixed-valence Iron Fluoride Heptahydrate and Related Compounds
Authors: Sakai Takuhiko , Tominaga Takeshi 
Published: July 2006

Abstract
The powder X-ray patterns of FeIIIFeIIF5·7H2O, AlFeIIF5·7H2O, FeIIIZnF5·7H2O and AlZnF5·7H2O indicate that they are all isomorphous. When the Mössbauer spectra of the fluorides containing iron were measured, FeII and/or FeIII oxidation states were recognized distinctly. The 19F NMR spectra reveal that all the fluorine atoms are bonded to the trivalent metal ion (Al or FeIII) in these compounds. On the basis of these results, a possible structure is proposed for FeIIIFeIIF5·7H2O.
Influence of Anhydrous Hydrogen Fluoride on Hen Egg-White Lysozyme. I. Effects on Native Hen Egg-White Lysozyme
Authors: Aimoto Saburo , Shimonishi Yasutsugu 
Published: July 2006

Abstract
The influences of anhydrous hydrogen fluoride on the native form of hen egg-white lysozyme under standard conditions of peptide synthesis were investigated by measuring the enzymatic activities of materials recovered from mixtures of anhydrous hydrogen fluoride and hen egg-white lysozyme. The enzymatic activity of hen egg-white lysozyme gradually decreased on incubation with anhydrous hydrogen fluoride at a given temperature. After incubation of the mixture at 0 °C for 60 min, at least three fractions could be separated by gel-filtration on Sephadex G-50. One of these was eluted in the same position as native lysozyme and was fully active enzymatically. Its ultra-violet, and circular dichroism absorptions were identical with those of native lysozyme, and the tetragonal crystals obtained from this fraction could not be distinguished from those of native lysozyme.
Nucleophilic Displacement Catalyzed by Transition Metal. I. General Consideration of the Cyanation of Aryl Halides Catalyzed by Palladium(II)
Authors: Takagi Kentaro , Okamoto Tadashi , Sakakibara Yasumasa , Ohno Atsuyoshi , Oka Shinzaburo , Hayama Naomi 
Published: July 2006

Abstract
The displacement reaction of various non-activated aryl halides with cyanide ions was investigated in the presence of palladium salts. Various aryl iodides and bromides were converted into the corresponding aryl cyanides in good yields under mild conditions. The addition of certain substances, such as potassium hydroxide and potassium carbonate, enhanced the catalytic activity. Hexamethylphosphoric triamide, in which potassium cyanide was scarcely soluble, was an outstanding solvent for the reaction. The reduced palladium species was supposed to be the active catalyst.
The Substituent Effect. VII. Substituent Chemical Shifts of NH Proton of Acetanilides
Authors: Fujio Mizue , Tsuno Yuho , Yukawa Yasuhide , Takai Yoshio 
Published: July 2006

Abstract
NMR chemical shifts of the NH proton of fifty-three m- and p-substituted acetanilides were determined in dilute DMSO solutions. The substituent chemical shifts were correlated with σ0 constants with considerable scatter. Deviations Were particularly significant for −R groups having α-hydrogen. Improved correlation was found for −R substituents with (σ0)DMSO values which had been derived from the phenol hydroxyl chemical shifts in DMSO. Application of the LArSR equation using the DMSO-modified substituent parameters gave a good linear correlation for all substituents; ΔδNHAc=0.686 [(σ0)DMSO+0.277 (Δ\barσR−)DMSO]. These results indicate that the deviations are caused primarily by solvent-modification of substituents, the modification being essentially the same for both the acetanilide and the phenol systems in DMSO. The lower r− value 0.277 in the chemical shifts for the acetanilides than for the phenols suggests that the π-electronic contribution of +R para substituents is less important in the acetanilide system than in the phenol one. The resonance substituent parameter for these solvent-modified substituents was found to be proportional to both (\barσpOH−\barσpNH), the difference between the apparent \barσp constants of the two systems, and to \barσp−0.85\barσm of each series. Estimation of a practical set of inductive and resonance substituent parameters for DMSO-modified substituents is attempted.
The Substituent Effect. VIII. Solvolysis of m- and p-Substituted α-Methylbenzyl Chlorides
Authors: Tsuno Yuho , Kusuyama Yoshiaki , Sawada Masami , Fujii Takahiro , Yukawa Yasuhide 
Published: July 2006

Abstract
The rates of solvolysis of twenty-two m- and p-substituted α-methylbenzyl chlorides were determined in 80% aqueous acetone. The relative rates at 45 °C are not correlated linearly with σ0 or σ. The use of Brown’s σ+ improves the fit but the resulting correlation is still concave. An excellent correlation, logk⁄k0=−4.950(σ0+1.147Δ\barσR+), was obtained by applying the LArSR equation. The r value 1.15 suggests that the π-electronic contribution relative to the inductive contribution of −R para substituents at the transition states differs with reaction, and is more important in the present α-methylbenzyl than Brown’s t-cumyl solvolysis (r=1.00 by definition). A set of Δ\barσ+ and σ+ corresponding to the substituent constants for unit r were calculated. The calculated σ+ values are in precise agreement with Brown’s primary σ+ values. The generality of the LArSR equation and some new substituent constants are illustrated.
A Stoichiometric Investigation of the Reaction of Nitrosylpentaamminechromium(2+) with Ethylenediaminetetraacetatoaquachromate(II)
Authors: Ogino Hiroshi , Tsukahara Keiichi , Tanaka Nobuyuki 
Published: July 2006

Abstract
The reaction of Cr(NH3)5NO2+ with CrII(edta)(H2O)2− gives four chromium products: CrIII-(edta)(H2O)−, Cr(NH3)63+, a reddish-violet species which is considered to be a chromium dimer with a +2 charge, and a trace amount of Cr(H2O)(NH3)53+.
Oxidation of Isocyanides by Hg(II), Tl(III), and Pb(IV) Acetates
Authors: Tanaka Sakuya , Kido Hiroshi , Uemura Sakae , Okano Masaya 
Published: July 2006

Abstract
Isocyanides were oxidized to isocyanates in acetic acid in the presence of Hg(II), Tl(III), or Pb(IV) acetate through acetoxymetallation. The reaction of an isocyanide with Tl(III) acetate in various alcohols gave the corresponding carbamates in good yields.
The Calculations of Dipole Polarizabilities and Anisotropies by the CNDO Method: The Effect of an Extended-basis Set
Authors: Shinoda Hiroyuki , Akutagawa Tatsuo 
Published: July 2006

Abstract
The dipole polarizabilities and the anisotropies of several small molecules have been calculated according to a formula derived from the time-dependent perturbation theory. The wave functions and the energies were calculated by means of the CNDO-CI version, with an extended-basis set. The effects on the calculated results of the introduction of the atomic vacant orbitals into the basis set have been discussed.
Photochemical Reduction of Vanadium(V) in Aqueous Perchloric Acid Solutions
Authors: Jeliazkowa Bojana G , Nakamura Shigeru , Fukutomi Hiroshi 
Published: July 2006

Abstract
It was found that irradiation of V(V) solution gives V(IV) and an equivalent amount of oxygen. The dependence of the quantum yield on light intensity, acid concentration, wave number and the concentration of V(IV) was investigated.
Photosolvation Reactions and Their Quantum Yields of Hexacyanocobaltate(III) in Non-aqueous Solvents
Authors: Nakamaru Katsumi , Jin Kazuo , Tazawa Atsuko , Kanno Masaru 
Published: July 2006

Abstract
The photoreactions of hexacyanocobaltate(III) in non-aqueous solvents (methanol, ethanol, acetonitrile, DMF, pyridine) caused by irradiation at 365 nm or 313 nm are found to be the photosolvation
[Co(CN)_6]^3- + Solv. \oversethν→ [Co(CN)_5(Solv.)]^2- + CN^-
In pyridine, in addition to the photosolvation product, a fluorescent substance which is perhaps an aromatic compound is also formed by the irradiation at 365 nm. The quantum yields are almost the same as that in aqueous solution. In ethanol, the quantum yields irradiated at both 313 nm and 365 nm are the same, indicating that the quantum yield is independent of the exciting wavelength. The sensitized photosolvation using several donors failed to occur because of the solubility limitation. Interesting spectral results are also reported.
Non-empirical Calculation of the G-Values for the Ionization and Excitations in Diatomic Molecules Irradiated by 100 keV Electrons
Authors: Okazaki Kiyoshi , Sato Shin 
Published: July 2006

Abstract
The binary-encounter collision theory has been applied to the calculation of the G-values for the ionization and excitations of diatomic molecules irradiated by 100 keV electrons. The obtained G-values of electrons are as follows, in the order of H2, N2, CO, NO, and O2: 2.83, 2.55, 2.68, 3.61, and 2.98. These values are in fair agreement with the experimental ones. The present non-empirical method is compared with the semi-empirical ones proposed by other investigators. The G-values of some other products were also calculated: the excited hydrogen atoms in the radiolysis of H2 (0.9) and the ozone formation in the radiolysis of O2 (12.6). These G-values are also in fair agreement with the experimental ones.
Anharmonic Potential Functions of Simple Molecules. II. Direct Numerical Diagonalization of Vibratinal Hamiltonian Matrix and Its Application to CO2 and CS2
Authors: Suzuki Isao 
Published: July 2006

Abstract
A general formalism is presented for the calculation of the vibration-rotation energy levels of linear symmetrical XY2 type molecules through direct numerical diagonalization of the vibrational hamiltonian matrix. This method is applied to the CO2 and CS2 molecules, of which the general quartic force fields have been known accurately. The results are compared with those obtained by an ordinary perturbation treatment, and the truncation effects of the matrix sizes as well as of the expansions of the potential functions are discussed. Special attention is paid to the peculiarities in the potential function of CO2 for which very strong mixings of the basis harmonic oscillator wave functions are observed. The general formula for evaluating the matrix elements of the transition moment are also discussed and its applicability to the problems of vibrational intensities and the dipole moment functions is discussed.
Vibrational Spectra and Molecular Structure of Ethyl Methyl Sulfide
Authors: Nogami Norimasa , Sugeta Hiromu , Miyazawa Tatsuo 
Published: July 2006

Abstract
The Raman spectra of the liquid, unannealed solid and annealed solid, and the infrared spectra of the gas, liquid, and annealed solid of ethyl methyl sulfide were measured. Normal vibrations were treated of the trans and gauche isomers. C–S stretching, CH2 rocking and skeletal deformation vibrations were discussed in relation with molecular structures. Only the gauche isomer was found to exist in the annealed solid. In the liquid state, the gauche isomer was found to be more stable, by 0.14±0.05 kcal/mol, than the trans isomer. The vibrational assignment made of ethyl methyl sulfide is consistent with those of related sulfides and disulfides.
The Preparation of 3- and 4-Fluorophthalic Anhydrides by Fluorodenitration
Authors: Ishikawa Nobuo , Tanabe Toshio , Hayashi Dan 
Published: July 2006

Abstract
3- And 4-fluorophthalic anhydrides were prepared by heating the respective nitrophthalic anhydrides with potassium fluoride with or without an aprotic polar solvent.
The Mechanism of the Hydrolysis of Condensed Phosphates. III. The Mechanism of the Hydrolysis of Trimeta- and Tetrametaphosphates
Authors: Watanabe Makoto , Sato Shoji , Saito Hajime 
Published: July 2006

Abstract
The hydrolysis of sodium trimeta- and tetrametaphosphates was run in water, dioxane–water, and formic acid–water solvents with an initial concentration of 0.025 mol/l at various pH values and temperatures. The hydrolysis of both the metaphosphates followed first-order kinetics with respect to the concentration of the phosphate under all the conditions studied and was an acid- and base-catalyzed reaction. In acidic solutions, the rate of hydrolysis of both the metaphosphates in water is faster than that in formic acid–water and slower than that in dioxane-water. Therefore, it is concluded that, in the formic acid–water solvent, the nucleophilicity of the water molecule may decrease on account of the solvation of the water molecule with the acid, while, in the dioxane–water solvent, since the scission of the hydrogen bond between water molecules may occur by the interaction of dioxane and water molecules, the nucleophilicity of the water molecule may increase. The hydrolysis of both metaphosphates in acidic solutions is considered to be an SN2 reaction, because the overall-reaction rate is highly dependent upon the nucleophilicity of the water molecule. In basic solutions, the rate of hydrolysis of sodium trimeta- and tetrametaphosphates in water is faster than or almost the same as that in dioxane-water. Consequently, the mechanism of the hydrolysis of both the metaphosphates in basic solutions seems to differ from that in acidic solutions. The increase in the rate of hydrolysis of small-ring phosphates in acidic solutions depends upon the activation energy and frequency factor, while that in basic solutions depends significantly upon the frequency factor. This may cause the difference in the solvent effect on the rate of hydrolysis of small-ring phosphates between acidic and basic solutions. The activation energy of the hydrolysis of both ring phosphates was 20–40 kcal/mol in the pH range of 1.0–12.5. The rate of hydrolysis of the metaphosphates in an aqueous sodium hydroxide solution is faster than that in an aqueous tetramethyl ammonium hydroxide solution and this can be attributed to catalysis by a sodium ion. The hydrolysis of sodium tripolyphosphate was also carried out in basic water and dioxane–water solvents. The solvent effect on the rate of hydrolysis of tripolyphosphate in basic solutions was the same as that in acidic solutions.
The Addition Reaction of Benzenesulfinic Acid to N-Substituted Maleimides
Authors: Matsuda Itsuo , Akiyama Keiichi , Toyoshima Takaaki , Kato Shinji , Mizuta Masateru 
Published: July 2006

Abstract
It was found that benzenesulfinic acid reacted with N-substituted maleimides in aqueous ethanol to give sulfoneimides in good yields. The rate for the reaction was determined by the use of the neutralization titration, the effect of a substituent in N-substituted maleimides on the rate was studied, and the reaction route of benzenesulfinic acid with N-substituted maleimide was deduced.
Reaction of Organoboranes with Lithium Aldimines. A New Procedure for the Synthesis of Unsymmetrical Ketones
Authors: Yamamoto Yoshinori , Kondo Kaoru , Moritani Ichiro 
Published: July 2006

Abstract
Unsymmetrical ketones are obtained in good yields via the reaction of dialkylchloroboranes with lithium aldimines followed by treatment with (i) thioglycolic acid and (ii) H2O2–NaOH. The reaction permits the introduction of both primary and secondary alkyl groups into R and R′ substituents of ketones (RR′C=O), and can even be extended to the accommodation of a functional group. The reaction of B-n-hexyl-9-borabicyclo[3.3.1]-nonane with lithium aldimine derived from n-butyllithium also gives unsymmetrical ketone, 5-undecanone, upon treatment with H2O2–NaOH.
Determination of Silver in Sea Water after Flotation with 2-Mercaptobenzothiazole
Authors: Hiraide Masataka , Mizuike Atsushi 
Published: July 2006

Abstract
Nanogram quantities of silver in 3000 ml of acidified sea water were quantitatively coprecipitated with 2-mercaptobenzothiazole. The precipitate was then floated with the aid of small nitrogen bubbles, and the silver determined by atomic-absorption spectrophotometry after wet oxidation. The silver concentration was 0.09 μg per liter.
Michael Reactions of α-Phenylthio and α-Phenyisulfinyl Crotonic Esters with Cyclic Enones
Authors: Hagiwara Hisahiro , Nakayama Kiyoshi , Uda Hisashi 
Published: July 2006

Abstract
The Michael reactivities of ethyl α-phenylthio- and α-phenylsulfinylcrotonates with 2-cyclohexenone, 3-methyl-2-cyclohexenone, and 3-methyl-2-cyclopentenone have been investigated.
Pressure Effect on the Optical Spectra of Some One-Dimensional Pt-Complexes
Authors: Hara Yoji , Shirotani Ichimin , Ohashi Yukako , Asaumi Katsuyuki , Minomura Shigeru 
Published: July 2006

Abstract
The absorption and luminescence spectra of the polycrystalline magnesium, barium, and potassium salts of tetracyano platinate (II) were measured at hydrostatic pressures up to 5.4 kbar. These three salts showed an anomalously large red shift with pressure in both the absorption and luminescence spectra. The X-ray powder diffraction measurement was carried out for the magnesium salt up to 70 kbar. At 70 kbar the Pt–Pt distance decreased from 3.16 Å to 2.93 Å, 7.3% in linear compressibility. In the low pressure region up to ∼20 kbar, the Pt–Pt distance was observed to decrease greatly. The intramolecular transition 5dz2→6pz energy was calculated as a function of the Pt–Pt distance. By comparing the calculated and observed values, such a large red shift in the absorption spectra was tentatively explained in terms of electrostatic stabilization of the intramolecular transition 5dz2→6pz due to the decrease of the intermolecular distance and due to the consequent increase of the 5dz2→6pz intermolecular CT character.
ESR Studies on the Anion Radicals of Some Triptycene and [2.2]Paracyclophane Derivatives
Authors: Hayashi Toyoharu , Mataga Noboru , Sakata Yoshiteru , Misumi Soichi 
Published: July 2006

Abstract
ESR spectra of anion radicals of some triptycene and [2.2]paracyclophane derivatives were observed and analyzed in order to study the delocalization interactions between composite aromatic rings.
An Investigation of the Hebb-Wagner’s d-c Polarization Technique I. Steady-state Chemical Potential Profiles in Solid Electrolytes
Authors: Mizusaki Jun-ichiro , Fueki Kazuo , Mukaibo Takashi 
Published: July 2006

Abstract
Using an electrochemical cell, Ag/AgX (X=Br or I)/C, the steady-state chemical potential profiles of silver in AgX were determined under d-c polarization conditions. Several Pt probes were attached to the AgX specimens, and the potential differences between the Ag electrode and the Pt probes were measured. It was found that, in order to obtain the correct chemical potential profiles, the Pt probes must be embedded in the specimen to avoid influences of the degradation of AgX at the surface of the specimen. The results obtained by the cell with carefully assembled probes revealed that Wagner’s theory holds for AgX.
A Convenient Synthesis of 5-Substituted-2,5-dihydro-2-furoic Acids
Authors: Masamune Tadashi , Ono Mitsunori , Matsue Hajime 
Published: July 2006

Abstract
Nine 5-alkyl- and 5-aryl-2-furoic acids were reduced under controlled Birch conditions and then esterified with acidic methanol. 2-Furoic acids with 5-alkyl groups gave good yields of methyl 5-alkyl-2,5-dihydro-2-furoates, which were obtained as mixtures of cis- and trans-diastereoisomers. These 2,5-dihydrofuroates revealed interesting spectroscopic properties; (1) large long-range coupling constants, 5–7 and 3–4 Hz, between protons at C2 and C5 were observed in the NMR spectra of cis- and trans-diastereoisomers, respectively, and (2) two high absorption maxima due to the ester carbonyl group of each furoate appeared near 1750 and 1730 cm−1 in the IR spectrum. On the other hand, the furoic acids with 5-aryl substituents afforded 5-arylpentanoate or 5-arylpent-3-enoate as main products. These esters would be produced as a result of reductive cleavage at C5 of 5-aryl-2,5-dihydrofuroates formed as intermediates.
Metalation of 2-Methyl-4H-pyran-4-one and its Reactions
Authors: Yamamoto Makoto , Sugiyama Noboru 
Published: July 2006

Abstract
2-Methyl-4H-pyran-4-ones formed metalated products in the presence of sodium amide in liquid ammonia, and the metalated product reacted with alkyl and aralkyl halides or carbonyl compounds to give alkylated or condensed products. Self condensation reactions of 2-methyl-4H-pyran-4-ones also occurred in liquid ammonia to give flavone and the γ-pyrone dimer.
Synthesis of Dihydrostreptobiosamine
Authors: Umezawa Sumio , Sano Hiroshi , Tsughiya Tsutomu 
Published: July 2006

Abstract
The isopropylidene derivative (4) of benzyl dihydrostreptoside and 3,4,6-tri-O-acetyl-2-amino-N-anisylidene-2-deoxy-α-l-glucopyranosyl bromide (7) were prepared, and they were coupled by a modified Koenigs-Knorr condensation. After hydrolysis of the N-ankylidene group of the product, N-methoxycarbonylation followed by N-methylation was accomplished to afford the fully protected derivative (9) of dihydrostreptobiosamine, which was, after deblocking, led to benzyl dihydrostreptobiosaminide and dihydrostreptobiosamine.
Total Synthesis of Dihydrostreptomycin
Authors: Umezawa Sumio , Yamasaki Tetsuro , Kubota Yutaka , Tsuchiya Tsutomu 
Published: July 2006

Abstract
Dihydrostreptomycin has been synthesized from dihydrostreptobiosamine and streptidine. A glycosyl chloride derivative (10) of the former was coupled with a protected derivative (26) of the latter to give a mixture of four isomeric glycosides, which were separated by chromatography. Deblocking of the desired glycoside led to dihydrostreptomycin. Several other protected derivatives of dihydrostreptobiosamine have also been described.
Synthesis of (3S, 4S)- and (3S, 4R)-4-Amino-3-hydroxy-6-methylheptanoic Acid, and Their N-(Acetyl-l-valyl-l-valyl) Derivatives
Authors: Kinoshita Mitsuhiro , Hagiwara Akito , Aburaki Shinpei 
Published: July 2006

Abstract
Natural (−)(3S,4S)-4-amino-3-hydroxy-6-inethylheptanoic acid (10a) present in pepstatins, specific inhibitors of acid proteases, and its (+) (3S,4R) diastereomer (10b) were synthesized starting from 3-deoxy-1,2-O-isopropylidene-α-d-erythro-pentodialdo-1,4-furanose (1) through highly stereoselective and stereospecific routes. The partial pep tide of pepstatin Ac, N-(acetyl-l-valyl-l-valyl)-(3S,4S)-4-amino-3-hydroxy-6-methylheptanoic acid (15a) and its (3S,4R) diastereomer (15b) were synthesized via azide-coupling of the t-butyl esters of 10a and 10b with acetyl-l-valyl-l-valine azide, respectively. Compound 15a inhibited proteolysis by pepsin, however, the diastereomer 15b showed no inhibition against pepsin.