bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Primary Process of the Photochemical Isomerization of Azanaphthalene N-Oxides
Authors: Hata Norisuke , Ono Isao 
Published: July 2006

Abstract
The quantum yields for the photochemical isomerization of azanaphthalene N-oxides, such as quinoline N-oxide and isoquinoline N-oxide, into lactam (Process I) or oxazepine (Process II) were determined in benzene (or carbon tetrachloride), in methanol, and in mixtures of the two solvents. Consequently, the reaction was revealed to be closely related to whether or not the N-oxide oxygen atom forms a hydrogen bond with the solvent molecule; that is, a strong hydrogen-bonding interaction between the excited singlet N-oxide and alcohol is essential for Process I, but not for Process II. It was further demonstrated that Process II occurred with the formation of powerful oxidants (probably oxaziridines) from the excited singlet N-oxide, whereas such an oxidizing species was not involved in Process I. The reaction mechanisms of Processes I and II were also discussed on the basis of the present experimental results.
Structure Analysis of a Collagen Model Polypeptide, (Pro–Pro–Gly)10
Authors: Okuyama Kenji , Tanaka Nobuo , Ashida Tamaichi , Kakudo Masao 
Published: July 2006

Abstract
A detailed conformation study of the polypeptide (Pro–Pro–Gly)10, synthesized as a collagen model, has been done using X-ray diffraction. Several structures having the observed helical parameters (unit height=8.61 Å, unit twist=51.4°) together with standard bond lengths and angles were generated and tested in terms of an existence of intermolecular van der Waals contacts and least squares calculations using 49 equatorial reflections. It was found from these studies that three polypeptide chains make a three-stranded rope of which the helical parameters are similar to but significantly different from those of the collagen models proposed so far. There exist two possible models for (Pro–Pro–GIy)10 according to the type of hydrogen bonding. One is the model having a hydrogen bond so-called ‘standard’ structure type, and the other has a hydrogen bond of collagen 11 type. The two-dimensional electron density map, synthesized with the observed structure factors, agrees well with these models. In the least squares calculations, atomic scattering factors were modified by taking into account of effects of amorphous water between the three-stranded ropes.
ESR of Hot Ions: Ni(I) Complex Ions Produced in Rigid Solutions by UV-Exposure
Authors: Amano Chikara , Fujiwara Shizuo 
Published: July 2006

Abstract
It has been shown that univalent nickel complex ions are produced in rigid solutions by electrons released on photo-ionization of N,N,N′,N′-tetramethyl-p-phenylenediamine. These complexes have the same g-values as those obtained by γ-irradiation, suggesting that the univalent nickel complex ions produced on γ-irradiation can be formed as a result of the capture of near-thermal electrons by bivalent nickel complexes. Upon UV-exposure at various sample temperatures between −196 °C and −70 °C, a new chemical species with g⁄⁄ of 2.37 and g⊥ of 2.128 has been observed, which appears to be an exchange-coupled dimer of the univalent hexaaqua nickel complex ions.
Solvent Inclusion Effects on the Structure and Electrical Conductivity of Benzidine-TCNQ Complex
Authors: Takahashi Noriaki , Yakushi Kyuya , Ishii Kikujiro , Kuroda Haruo 
Published: July 2006

Abstract
The solvent-containing modification of benzidine (BD)-tetracyanoquinodimethane (TCNQ) complex is a new type of inclusion compound where solvent molecules are included in the channels of the host lattice formed by hydrogen bonding and charge-transfer interaction between BD and TCNQ. The electrical conductivity at 18 °C is 7×10−10 ohm−1·cm−1 and the activation energy of semiconduction is 0.54 eV in the solvent-free state, but they change to 10−4–10−6 ohm−1·cm−1 and 0.1–0.2 eV, respectively, when an aliphatic solvent is included, and to 10−6–10−9 ohm−1·cm−1 and 0.3–0.5 eV, when benzene or its derivatives is included. By examining the changes of the electrical conductivity and the spin density of BD·TCNQ·[CH2Cl2] system with the pressure change of the ambient dichloromethane vapor, it is concluded that the conductivity of BD·TCNQ·[CH2Cl2] is strongly controlled by the amount of solvent vacancies in the crystal lattice. The correlations between the electrical properties and crystal structures of solvent-containing modifications are discussed.
Silver Ion Catalysed Oxidation of Primary Aliphatic Amines by Potassium Peroxydisulfate — A Kinetic Study
Authors: Babu J Sreekantha , Joshi Km Veena , Bhattacharya A K 
Published: July 2006

Abstract
A detailed kinetic study of the oxidation of propyl-, isopropyl-, butyl- and isobutylamines by potassium peroxydisulfate in presence of silver ions has been carried out in aqueous medium. The effects of silver ion concentration and various neutral salts have been detected and the variation of the order of reaction with respect to amine had been explained. The activity of Ag+ ion has been correlated with the amine structure and probable rate law and the mechanism has been proposed.
π-Electron Structure of Some Nonbenzenoid Hydrocarbons Using β-Variable Method
Authors: Chatterjee Subrata , Das Gupta Nanda K 
Published: July 2006

Abstract
The molecules pentaleno[def]heptalene, cyclohept[fg]acenaphthylene, naphth[cde]azulene and cyclohept[bc]acenaphthylene have been studied using β-variable methods proposed by Dewar et al. and Yamaguchi et al. The predicted results are compared with experimental values and with other theoretical results.
Sterically Controlled Substitution of Copper(II) with 3,3′-Bis[N,N-bis(carboxymethyl)aminomethyl]-o-cresolsulfonphthalein
Authors: Yamada Mutsuo 
Published: July 2006

Abstract
The rate constants for the formation of the diprotonated bimetallic complex of copper(II) with 3,3′-bis[N,N-bis(carboxymethyl)aminomethyl]-o-cresolsulfonphthalein (XO) have been determined by the stoppedflow method. The results are interpreted in terms of the reactions, Cu+LH2\ightleftharpoonsCuLH2 (Remark: Graphics omitted.) Cu2LH2 and Cu+LH3\ightleftharpoonsCuLH2+H (Remark: Graphics omitted.) Cu2LH2+H. The over-all rate constants, k1 and k2 for both reactions are determined to be k1=(3.6±0.3)×106M−1s−1 and k2=(8.7±1.3)×103M−1s−1 and 25.0 °C and I=0.1 M.
The Electrochemical Fluorination of Aliphatic Primary Monohydric Alcohols and Aldehydes
Authors: Abe Takashi , Nagase Shunji , Baba Hajime 
Published: July 2006

Abstract
The perfluorocyclic ethers as well as the perfluoroalkanoyl fluorides were obtained by the electrochemical fluorination of primary monohydric alcohols and aldehydes containing 4–8 carbon atoms. The five-membered rather than the six-membered perfluorocyclic ethers were formed as the cyclic products. The over-all yields of the perfluorocyclic ethers and the perfluoroalkanoyl fluorides from the alcohols were in the range of 10–20%, and 3–12% respectively. Those from the aldehydes were poor because of the formation of a considerable amount of tarry by-products. The physical properties of the perfluorocyclic ethers obtained are also described.
Syntheses of Polymerizable Acetals. I. Vinylbenzaldehyde Acetals with Perfume Alcohols
Authors: Kamogawa Hiroyoshi , Okabe Shinya , Nanasawa Masato 
Published: July 2006

Abstract
Several acetal monomers and a hemiacetal monomer of vinylbenzaldehydes were synthesized from the reaction with some perfume alcohols in the presence of p-toluenesulfonic acid as an acid catalyst. It was found that primary alcohols such as citronellol and geraniol with the exception of cinnamyl alcohol afforded acetal monomers in high yields, secondary alcohols such as borneol and menthol in low yields, with the latter affording only hemiacetal monomer, and linalool, a tertiary alcohol, neither acetal nor hemiacetal monomers. The radical polymerizations of the acetal and hemiacetal monomers synthesized provided soluble polymers which easily release perfume alcohols under mild acidic conditions.
Reactions of 2,4-Dialkoxy-1,3-diphenyl-1,3,2,4-diazadiphosphetidines with Benzil, Benzalacetophenone, and α-Phenyliminobenzyl Phenyl Ketone
Authors: Kawashima Takayuki , Inamoto Naoki 
Published: July 2006

Abstract
2,4-Diethoxy-1,3-diphenyl-1,3,2,4-diazadiphosphetidine (1a) reacted with benzil, benzalacetophenone, and α-phenyliminobenzyl phenyl ketone in refluxing o-dichlorobenzene to give 2-ethoxy-3,4,5-triphenyl-Δ4-1,3,2-oxazaphospholine 2-oxide, 2-ethoxy-1,3,5-triphenyl-Δ4-1,2-azaphospholine 2-oxide, and 2-anilino-3,4,5-triphenyl-Δ4-1,3,2-oxazaphospholine 2-oxide, respectively. Under mild conditions, reaction of 1a with benzil gave a Ramirez type 1:2 adduct, which thermally decomposed to give oxazaphospholine derivatives.
Optical Activation of Racemic α-Substituted Carbonyl Compounds Using Optically Active Amines
Authors: Matsushita Hajime , Noguchi Masao , Yoshikawa Sadao 
Published: July 2006

Abstract
Hydrolysis of immonium salts of enamines consisting of optically active amines and racemic α-substituted carbonyl compounds with hydrochloric acid gave the corresponding optically active carbonyl compounds. The NMR spectra showed that the immonium salt is a mixture of two diastereomeric isomers. The mechanism of the optical activation is discussed on the basis of an isotope labeling experiment and the NMR spectra.
The Oxidation of 3-(2-Hydroxyphenyl)coumarins with Lead Tetraacetate
Authors: Kurosawa Kazu , Nogami Keifumi 
Published: July 2006

Abstract
Five 3-(2-hydroxy-4-methoxyphenyl)coumarins (Ia–Ie) were oxidized with lead tetraacetate to the corresponding 6H-benzofuro[3,2-c][1]benzopyran-6-ones (IIa–IIe) and 3-(1-acetoxy-4-methoxy-2-oxo-3,5-cyclohexadienyl)coumarins (IIIa, IIIb, and IIId). Four 3-(3,4-dimethoxy-2-hydroxy-phenyl)coumarins (If–Ii) gave the corresponding 3-(1-acetoxy-3,4-dimethoxy-2-oxo-3,5-cyclohexadienyl)coumarins (IIIf–IIIi).
Synthesis and Biological Activities of 2-Amino-2-deoxy- and 6-Amino-6-deoxy-α-d-glucopyranosyl-2,5-dideoxystreptamines
Authors: Ogawa Seiichiro , Funaki Yuji , Iwata Keiji , Suami Tetsuo 
Published: July 2006

Abstract
To investigate a relationship between structural features of aminocyclitols and biological activities of aminocyclitol antibiotics, 4-O-(2′-amino-2′-deoxy-α-d-glucopyranosyl)- and 4-O-(6′-amino-6′-deoxy-α-d-glucopyranosyl)-2,5-dideoxystreptamines (8 and 15a) have been synthesized, and their biological activities against several microorganisms were determined.
A Potential Synthetic Intermediate of dl-Carnosic Acid
Authors: Oommen P Kurian 
Published: July 2006

Abstract
The Birch reduction of 2,7-dimethoxy-3-isopropylnaphthalene (IIb), which itself was made from IIa in five steps, followed by acid hydrolysis yielded the tetralone IIIa and the latter was carboxymethylated to IIIb by reaction with dimethyl carbonate and sodium hydride. Michael condensation of IIIb with methyl vinyl ketone yielded the unsaturated ketone IV. The tricyclic ketone IV on methylation followed by thioketalisation gave the thioketal IXa and the latter on Raney nickel desulfurisation yielded Ic.
A Shock-tube Investigation of Ethylene–Oxygen–Argon Mixtures. Chemi-ionization and Apparent Activation Energy
Authors: Hidaka Yoshiaki , Nishi Tomofumi , Suga Masao 
Published: July 2006

Abstract
The reaction of ethylene–oxygen mixtures highly diluted with argon was studied over the temperature range of 1400–1800 K behind reflected shock waves by monitoring the total ionization. A kinetic study of the chemi-ionization in the ethylene oxidation was undertaken. It was inferred that the mechanism of CHO+ formation was dependent on the composition and the temperature, and that the rate-determining step for the chemi-ionization was C2H3+O2→C2H3O+O.
Solvent Effect on the Raman Spectra of Mercury(II) Halides
Authors: Sone Kozo , Aritaki Makiko , Hiraoka Keiko , Fukuda Yutaka 
Published: July 2006

Abstract
Raman spectra show that the Hg–X bond strengths in mercury (II) halides are remarkably weakened by the interaction with certain solvents. Relations between the degree of this weakening and (a) the Lewis basicity (Gutmann’s donor number) of the solvent and (b) the ionic character of the Hg–X bond are pointed out, together with a simple explanation.
Origin of the Oxygen Atom in the Nitrosomesitylene Formed by the Oxidation of Mesidine with Fremy’s Salt
Authors: Takahashi Tomoji , Minato Hiroshi , Kobayashi Michio 
Published: July 2006

Abstract
The mechanism of the oxidation of aromatic amines with Fremy’s salt was investigated by use of 18O-labelled compounds. It was shown that the nitroso-oxygen atom originates not from water but from the nitroxide oxygen and sulfonate oxygen atoms of Fremy’s salt.
Synthesis of 2-Aminonaphthalene-1-thiol and Its Conversion into 8-Nitro-7H-benzo[c]phenothiazine
Authors: Gupta R R , Jain S K 
Published: July 2006

Abstract
Synthesis of 2-Aminonaphthalene-1-thiol by hydrolytic cleavage of 2-aminonaphtho(2′,1′: 4, 5)thiazole and its conversion into 8-nitro-7H-benzo[c]phenothiazine via Smiles rearrangement in situ are reported.
Synthesis of Succin-as-eins. III. Dyes Derived from β-Benzoylpropionic, β-(3-Acenaphthoyl)propionic and β-(α-Thenoyl)propionic Acids
Authors: Gopal R , Gupta P C , Garg S P 
Published: July 2006

Abstract
A number of succin-as-eins have been prepared by condensing β-benzoylpropionic, β-(3-acenaphthoyl)propionic and β-(α-thenoyl)propionic acids with phenol, resorcinol, catechol, quinol, phloroglucinol, pyrogallol and orcinol.
The Effect of Metal Oxides on the Transformation of Copper Phthalocyanine Crystals in Organic Solvents
Authors: Kawashima Norimichi , Suzuki Takao , Meguro Kenjiro 
Published: July 2006

Abstract
The dimorphic transformation of copper phthalocyanine crystals was examined by means of X-ray diffraction analysis and electron-micrograph observation, for α-copper phthalocyayine and metal oxides of various mixing ratios with respect to weight were ground using a grinder and suspended in an organic solvent. The α-β transformation of copper phthalocyanine is accelerated by the presence of metal oxides such as alumina, magnesia, and zinc oxide. Particularly, alumina has a remarkable effect on the acceleration of β-copper phthalocyanine formation. The rate of transformation increases with the amount of metal oxide and the grinding time for a mixture of copper phthalocyanine and alumina. The activation energy for the α-β transformation in a (1 : 1) mixture of copper phthalocyanine and alumina ground for 30 min was calculated to be 12.0 kcal/mol.
Group Interactions in Polyelectrolytes. XII. Amination Kinetics of Chloromethylated Polystyrene in Binary Solvent Systems Composed of Dioxane and Dipolar Aprotic Solvents
Authors: Kawabe Hiroshi 
Published: July 2006

Abstract
The activation parameters (ΔG\eweq, ΔH\eweq, ΔS\eweq) in the amination reaction of chloromethylated polystyrene (CMPS) and benzyl chloride with s-butylamine in N,N-dimethylformamide (DMF)–dioxanes mixtures and with 2 amino-1-butanol in dimethyl sulfoxide (DMSO)–dioxane mixtures were investigated as a function of x1 the mole fraction of DMF or DMSO in the binary mixed solvents. A similar dependence of the parameters on x1 was found in both systems, and the observed values of the parameters were in fair agreement with those calculated on the basis of Kondo and Tokura’s theory concerning reaction rates in binary mixed solvents, assuming that the activated complex is solvated selectively with DMF or DMSO to form an addition product. The solvation in the DMSO–dioxane system was stronger than that in the DMF–dioxane system. Although ΔG\eweq decreases relatively uniformly with the increase in x1, ΔH\eweq decreases sharply and reaches nearly a constant value at x1≈0.2. It was suggested that the increase of TΔS\eweq in the range of x1&gt;0.2, which is approximately proportional to that of x1, may be due to the relative increase in the configurational entropy change of the reaction system on transfer from dioxane to the dipolar aprotic solvents.
The Study of the Raman Band Shape of Sulfuric Acid and Proton Transfer
Authors: Ikawa Shun-ichi , Kimura Masao 
Published: July 2006

Abstract
The Raman bands of sulfuric acid and ammonium sulfate in aqueous solutions were observed in the S–O stretching region and were resolved into components with a Voigt profile. The concentration dependence of the half band-widths was examined. The 980 cm−1 band of SO42− in acidic solutions was determined to have a width of 8.0±0.3 cm−1 when unbroadened by any chemical process. In the concentration-half-width curve for this band, two conspicuous bends were found, at about 2 M and 8 M stoichiometric concentrations of H2SO4. It seems that the former bend is attributable to the disappearance of water clusters, and the latter, to the partial defect of the primary hydration shell of the oxonium ion. The interrelation between the half-widths of the 980 cm−1 and 1050 cm−1 bands suggests that the formation of the HSO4−·H3O+ ion pair is related to the spectroscopic lifetime of HSO4−.
Electric Dipole Moment of 4-Chloro-2,3-tetra-, penta-, and hexamethylene Quinoline
Authors: Dipti Miss , Rastogi Pushti Prakash 
Published: July 2006

Abstract
Electric dipole moments of 4-chloro-2,3-tetra-, penta-, and hexamethylene quinolines have been determined in benzene solution at a frequency of 1 MHz by Guggenheim method. The reported results indicate that these compounds are non-planar and the dipole moment increases with the increase in the size of substituted methylene ring.
Stability of Dextran Solutions
Authors: Aizawa Masuo , Suzuki Shuichi , Kuoka Tatuo , Nakajima Noriyasu , Iwao Yutaka 
Published: July 2006

Abstract
In order to clarify the accessibility of dextran to both water and dextran the onset of turbidity in dextran solution was studied by means of viscosimetry and near-infrared and PMR measurements. Mole fraction of monomeric and hydrogen-bonded water species in dextran solutions were calculated for various concentrations of dextran solutions from 2ν1+ν3 and ν1+ν2+ν3 bands where ν1, ν2, and ν3 are the fundamental vibrations of symmetric stretching, bending and asymmetric stretching, respectively. The extent of hydrogen bonds was estimated from PMR chemical shift of water proton. A dextran solution was characterized by a low concentration in monomeric water. An anomalous time dependence of viscosity and PMR chemical shift was observed for concentrated solutions. A mechanism has been proposed for gelation and the onset of turbidity, stress being laid on comparable accessibility of dextran to both water and dextran.
Temperature Dependence of the Dielectric Constants of Potassium-Chloranil Salt and Würster’s Blue Perchlorate
Authors: Ishii Kikujiro , Kaneko Katsumi , Kuroda Haruo 
Published: July 2006

Abstract
The dielectric constants of potassium-chloranil salt(K+CA−) and Wiirster’s blue perchlorate (WBP) were measured around their phase-transition temperatures in the X-band microwave region. In the case of K+CA−, a sudden increase in the dielectric constant was observed accompanying a change to the low-temperature phase. This is interpreted to arise from the change in electronic polarization associated with a marked increase in the intensity of the charge-transfer band in the near-infrared region. An anomalous peak and associated gradual changes were observed in the temperature dependence of the dielectric constant of WBP around the phase transition temperature. The difference in dielectric behavior of these two cases is discussed in relation to the optical absorption spectra and other properties of the crystals.
Lactone Carboxylic Acids. VIII. A Synthesis of γ-Substituted α-Aminobutyrolactones from Ethyl γ-Substituted α-Hydroxyaminoaconates
Authors: Torii Sigeru , Ukida Masasi , Kano Hiromichi , Furuta Takuya , Tanaka Hideo 
Published: July 2006

Abstract
The conversion of α-hydroxyaminoaconates 1a and 1b to α-aminoaconates 2a and 2c was described, involving a novel reduction of the α-hydroxyamines on treatment with p-toluenesulfonyl chloridep–yridine in 62.1–89.5% yields. In the case of the reduction of 1b N-tosyloxy derivative 11b was isolated. α-Amino-γ-butyrolactones 3 and 4 could be obtained by hydrogenation of N-acetates of 2a and 2c. Ammonolysis of 2-hydroxy-2-butenolides 5a and 7a prepared from acid-hydrolysis of 1b also gave α-aminobutyrolactones 6, 8a, 8b, 9, and 10.
The Coordinative Behavior of the Ethereal Oxygen Atom in Cobalt, Nickel and Copper Complexes with Schiff Bases Obtained from Salicylaldehyde Derivatives and 2-(Aminomethyl)furan
Authors: Yamada Shoichiro , Yamanouchi Kuniko , Mori Wasuke , Kishita Michihiko 
Published: July 2006

Abstract
Cobalt(II), cobalt(III), nickel(II), and copper(II) complexes with N-(2-furylmethyl)salicylideneaminates (abbreviated as X–sal–fum) were synthesized. In addition to the M (X–sal–fum)2 type complexes, those of the formula Cu (X–sal–fum) Cl were obtained in crystals. The complexes Co (X–sal–fum)3 are six-coordinate, octahedral. The cobalt(II) complex is four-coordinate, tetrahedral and the nickel(II) complexes are four-coordinate, planar. In these complexes, the ligands X–sal–fum function as bidentates, the furan oxygen atom not being bound to the metal ions. The results are compared with those reported previously for related ligands. It is most likely that the complexes Cu(X–sal–fum)Cl consist of binuclear complexes with spin-spin interaction between copper(II)ions.
Stereoselectivities in Mixed Ligand Complexes of Cobalt(III), with l-Asparagine as a Ligand
Authors: Takenaka Hideto , Shibata Muraji 
Published: July 2006

Abstract
The [Co(ox)(l-aspNH2)(en)] complex as well as the [Co(l-aspNH2)3−n(l-asp)n]n− complexes (n=1,2) have been prepared and separated into their diastereoisomers by means of column chromatography. The structures of the isomers thus isolated have been characterized by their absorption, CD, and PMR spectra. Stereoselectivity in the [Co(ox)(l-aspNH2)(en)] complex has been found for the fac-Λ and mer-Δ isomers, and those in the [Co(l-aspNH2)3−n(l-asp)n]n− complexes, for the fac-Δ and mer-Λ isomers. These results have provided proof of the stereoselective effect due to the chelated l-aspar aginate ion.
Free Radicals Produced by γ Irradiation of Nitroalkanes in Frozen Glassy Acidic Solutions
Authors: Shiotani Masaru , Forchioni Alain , Chachaty Claude 
Published: July 2006

Abstract
The scavenging of paramagnetic species by nitroalkanes formed during the γ irradiation of aqueous 6.4 molar sulfuric acid glasses has been studied by using ESR. Nitroalkanes give rise to RNO2H radiclas, the nitrogen hyperfine coupling of which has the values A⁄⁄N=48 G and A⊥N=18 G with g⁄⁄=2.0035 and g⊥=2.0075. The RNO2H yields for 0.5 molar solutions of nitromethane and 2-nitro-2-methyl-propanol are G\simeq4 and G\simeq3, respectively. G(SO4−+OH.) is roughly idenpendent of the nitroalkane concentration. These results are interpreted as the scavenging of hydrogen atoms due to the energetic recombination of non-hydrated primary species (H2O+, OH., e−) according to an assumption of Hamill.
Semiempirical Molecular Orbital Considerations of the Electronic Structures of Transition Metal Complexes. I. Dioxygen Nickel Complexes
Authors: Tatsumi Kazuyuki , Fueno Takayuki , Nakamura Akira , Otsuka Sei 
Published: July 2006

Abstract
The electronic structure of Ni(O2)(HNC)2 as a model of “side-on” coordinated dioxygen nickel complexes has been investigated by the INDO method. Calculations show that the square-planar geometry is more stable than the pseudotetrahedral form in accord with the observed structure of Ni(O2)(t-BuNC)2. The central nickel atom possesses an approximately zerovalent configuration: (3d)8.5 (4s)0.5 (4P)1.0. The dioxygen-nickel bonding is effected primarily through the donation and back–donation of electrons in which the O2 πu and πg* orbitals parallel to the molecular plane participate. It is predicted that both the Ni–O and O–O bondings tend to have greater covalent bond strengths as the electron-attracting ability of the ligand isocyanide increases. Attempts are made to assign the electronic spectra.