bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Photochemical Raction of 2-Alkoxy-1,4-naphthoquinones with Olefins. II. The Formation of Tetrahydropyran-ring Compounds
Authors: Otsuki Tetsuo 
Published: July 2006

Abstract
The photochemical reaction of 2-alkoxy-1,4-naphthoquinones with numerous types of olefins was investigated. The reaction was found to proceed smoothly in possible combinations of quinones and olefins to give photo-addition compounds in good yields. The structure of the addition compounds was determined to be 10 by their elemental analyses, mass, IR, PMR, and chemical reactions. The photo-addition reaction is characterized by the formation of a tetrahydropyran ring. This type of photo-addition reaction has not been previously known. The scope and limitations of the new photochemical reaction were described.
Spectrophotometric Studies of the Acidities of Dichlorophene and Hexachlorophene
Authors: Inoue Hiroyasu , Asaoku Naomi 
Published: July 2006

Abstract
It has been found that dichlorophene (bis-(2-hydroxy-5-chlorophenyl)methane) and hexachlorophene (bis-(2-hydroxy-3,5,6-trichlorophenyl)methane) have abnormally high acidities as compared with the corresponding reference compounds, i.e., 2-methyl-4-chlorophenol and 2,4,5-trichlorophenol respectively. The values of pKa for the first and second ionizations of dichlorophene in a mixed solvent of ethanol and water (1 : 1) were determined to be 9.10 and 13.1, and those of hexachlorophene, to be 5.87 and 11.9, at 18 °C. On the basis of the infrared spectra, these observations could be interpreted in terms of the additional stabilization of the resulting monoanions of these bis-phenolmethanes by means of the intramolecular hydrogen bondings between the OH and O− groups.
α,β-Unsaturated Carboxylic Acid Derivatives. VI. New Synthesis of N-Acyl-α-dehydroamino Acid Esters
Authors: Shin Chung-gi , Nanjo Katsumi , Ando Eiichi , Yoshimura Juji 
Published: July 2006

Abstract
A new synthetic route to α,β-unsaturated N-acyl-α-amino acid esters (N-acyl-α-dehydroamino acid esters) is described. The dehydroamino acid esters were prepared by the dehydration of α-(N-acylhydroxyamino) acid esters (10), derived from the acylation of α-hydroxyamino acid esters (2 and 6), and by the elimination of carboxylic acid from α-(N-acyl-O-acetyl), α-(N,O-diacetyl, dipropionyl and diethoxycarbonyl-hydroxyamino) acid esters, obtained by the acylation of 2, 6 and 10, in the presence of triethylamine.
Factors Affecting: the Line-width of Nitrogen Superhyperfine Structure in the ESR Spectra of Copper(II) Complexes
Authors: Nonaka Yasuomi , Tokii Tadashi , Kida Sigeo 
Published: July 2006

Abstract
ESR spectra were measured for several series of copper(II) complexes in an attempt to find the best-observable condition for 14N-superhyperfine structure. It was demonstrated that in addition to the temperature and the dilution factors the line-width of 14N-superhyperfine structure is broadened out by the following factors; 1) deviation from square planar configuration around a copper ion, i. e., deformation to elongated octahedron or square pyramid due to weak bonding along the tetragonal axis and/or distortion of coplanality of the coordination bond effected by some steric condition, and 2) the presence of protons that can couple with an unpaired electron and 14N-nuclei.
The Thermal Polycondensation of Glycine in the Presence of Urea
Authors: K\={o}zai Yasuaki , Ikeda Yoshiyuki , Yoshida Masakazu 
Published: July 2006

Abstract
After the discovery of the polycondensation of glycine to form the glycine oligomer by heating in the presence of urea in a sealed tube, we investigated in order to establish the optimum reaction conditions as well as to study the reaction mechanism. The optimum conditions are attained when a mixture of 0.0133 mol (1 g) of glycine and 0.0016 mol (0.1 g) of urea is heated at about 160 °C for 20–30 hr. Under these conditions, an oligomer, composed of glycine units, with a polymerization degree of 17–18 is obtained with a 50–52% yield. The mechanism of oligomer formation is considered to be as follows: first, the urea is melted and part of it is used for converting the glycine to the corresponding amide. The glycinamide thus formed and the glycine dissolve locally in the molten urea, resulting in condensation between them. A repetition of the condensation leads to longer peptide chains.
Methylene Analogs of Cyclobutenedione. VIII. The Oxidation of 1-Halo-and 1,2-Dihalo-3,4-bis(diphenylmethylene)cyclobut-1-enes
Authors: Toda Fumio , Monden Fumio , Ohi Mitsuru 
Published: July 2006

Abstract
The ether peroxide-catalyzed oxidation of 1-chloro- (X) and 1,2-dichloro-3,4-bis(diphenylmethylene)cyclobut-1-enes (V) afforded two ring-opened products, XI and VI respectively. However, neither X nor V was oxidized by photooxidation. By the photooxidation, 1-bromo- (XVI) and 1,2-dibromo-3,4-bis(diphenylmethylene)cyclobut-1-enes (II) were converted to cyclobutanones, XIII and I respectively. Although II was inert to the peroxide-catalyzed oxidation, XVI was oxidized by this procedure. Nevertheless, the main product of the latter reaction was the cyclobutanone (XIII). The mechanisms of these reactions were described.
Dye-sensitized Photolysis of Diazonium Compounds in the Presence of Thioacetamide
Authors: Inoue Eiichi , Kokado Hiroshi , Ikawa Tsuneo , Yamase Toshihiro , Inoue Yasuo 
Published: July 2006

Abstract
Effects of solution pH and molecular oxygen on the quantum yields of methylene blue-sensitized photolysis of diazonium salt have been studied in aqueous solutions, using thioacetamide as an activator. The quantum yield increased with an increase in pH when other parameters were kept constant. The presence of oxygen at pH (&lt;7) promoted dye sensitization, but at pH (&gt;7) dominance of the pathway of oxygen quenching of the excited dye triplet caused its suppression. The polymerization of acrylamide in the deaerated solution was readily initiated by dye-sensitized photolysis. A mechanism involving an electron transfer to diazonium cation from unprotonated semimethylene blue formed by a photoredox reaction between excited triplet dye and thioacetamide was in line with these observation.
Magnetic Susceptibilities of Octacoordinated Uranium (IV) Complexes
Authors: Yoshimura Tetsuhiko , Miyake Chie , Imoto Shosuke 
Published: July 2006

Abstract
Magnetic susceptibility measurements were carried out on octacoordinated uranium(IV) complexes, such as tetrakis(acetylacetonato)uranium (IV), tetrakis(trifluoroacetylacetonato)uranium (IV), tetrakis(benzoylacetonato)uranium(IV), tetrakis(dibenzoylmethanato)uranium(IV), tetrakis(thenoyltrifluoroacetonato)uranium(IV), tetrakis(cupferronato)uranium(IV), and uranium(IV)tetrachloride, in the temperature range from room temperature to the temperature of liquid nitrogen or liquid helium. The Curie-Weiss law holds above the temperature of liquid nitrogen, with a magnetic moment of 3.5–2.92 BM. For the latter two complexes, a temperature-independent paramagnetism was observed in the low temperature range; the other complexes also seemed to show the same trend. We tried to interpret the magnetic behavior on the basis of the crystal-field model of the square antiprism structure or the dodecahedron structure of the complexes.
The Dianion of 9,9′-Bixanthenylidene and Its Reaction with Oxygen. A Contribution to Photochromism
Authors: Hoshino Mikio , Matsui Masao , Imamura Masashi 
Published: July 2006

Abstract
The anion produced by the reduction of 9,9′-bixanthenylidene with sodium or potassium metal was identified with the dianion by pulse radiolysis. It appears that the dianion is twisted around the central ethylenic bond. The dianion reacts with oxygen at 100 K to produce a colored form, the spectrum of which is in accord with that of the transient species observed in the flash photolysis of 9,9′-bixanthenylidene. The colored form is expected to be produced via a twisted 9,9′-bixanthenylidene, because the oxygen is considered to remove electrons from the twisted dianion. This twisted intermediate may also participate in the photochromic or thermochromic reaction in which the same-colored form is produced.
Calorimetric Study of Glassy State. IX. Thermodynamic Properties of Stannous Chloride Dihydrate and Dideuterate Crystals
Authors: Matsuo Takasuke , Oguni Masaharu , Suga Hiroshi , Seki S\^{y}uzô , Nagle Johan F 
Published: July 2006

Abstract
The heat capacity of SnCl2·2H2O and SnCl2·2D2O crystals, substances with layer structure, was measured from 13 to 300 K. Anomalies due to ordering of the hydrogen (deuterium) position were observed at TC(H2O)=217.94 K and at Tc(D2O)=234.47±0.05 K. The total entropy change of the transition was estimated to be 4.6 J K−1 mol−1 for both compounds. An exact calculation of the high temperature entropy based on the two-dimensional lattice model gave 3.13 J K−1 mol−1. The critical indices α± of the divergent heat capacity anomalies are as follows: α+(H2O)=0.53, α−H2O)=0.48, α+(D2O)=0.57, α−(D2O)=0.54. Another heat capacity anomaly was found at 140–160 K where the heat capacity values depended on the thermal history of the specimen. The enthalpy relaxation observed at the temperature region was analysed by use of the first-order rate equation, giving the activation enthalpies ΔHa(H2O)=49.9 kJ mol−1 and ΔHa(D2O)=49.8 kJ mol−1. The concept of long-range-ordered glassy state was introduced for description of the non-equilibrium state of the present substances below 140 K. A general consideration of the relation between molecular relaxation and phase change in terms of the Deborah number is presented.
The Molecular and Crystal Structure of the Cyclic Tetramer of Formaldehyde, 1,3,5,7-Tetroxocane
Authors: Chatani Yozo , Yamauchi Tadafumi , Miyake Yasuhiko 
Published: July 2006

Abstract
The crystal structure of the cyclic tetramer of formaldehyde, 1,3,5,7-tetroxocane, has been determined by the X-ray diffraction method. The unit cell is monoclinic, with a=11.455, b=4.160, c=12.232 Å, and β=108.4°. The space group is C2/c, and there are four molecules per unit cell. The structure was solved by using a molecular transform method and was refined by the block-diagonal least-squares method to a final R factor of 0.051, using 728 reflections measured with an automated four-circle diffractometer. The molecules in the crystal are of the so-called crown form, with an approximate C4v symmetry but an exact C2 symmetry. The torsion angles about the four independent C–O bonds appear in two distinguishable values: two bonds with 83.7 and −83.6°, and the other two bonds with 93.6 and −94.1°. The average C–O bond length is 1.403 Å, while the average C–O–C and O–C–O bond angles are 116.6 and 113.8° respectively. The deformation from a regular crown form by taking the two distinguishable torsion angles and the increase in bond angles is favorable to compensating for the intramolecular H···H repulsions; the close H···H distances in the deformed crown form are 2.16 and 2.20 Å.
A New Method for Determination of Self-diffusion Coefficients in Solid Solutions
Authors: Kurihara Seiichi , Fueki Kazuo , Mukaibo Takashi 
Published: July 2006

Abstract
A new method for obtaining the self-diffusion coefficients of A in the AY–BY solid solution has been proposed. In this method, the tracer diffusion of A* and the interdiffusion between AY and BY are carried out simultaneously, and the self-diffusion coefficients are determined as a function of composition over the whole range of composition in a similar way as the Boltzmann-Matano analysis. Since this method employs a diffusion couple consisting of single crystals of AY and BY, one can avoid troubles and errors due to segregation and/or phase separation which are often encountered in experiments using solid solutions as specimens. In order to confirm the validity of the proposed method, Dcl* in the TlCl–TlBr system and DAg* and DNa* in the AgBr–NaBr system have been determined at 400 °C by this method and compared with the results obtained by the conventional method. A good agreement has been found between them.
The Triplet States of 1,3,5-Tricyanobenzene Complexes with Methyl Substituted Benzenes
Authors: Matsumoto Satoru , Nagakura Saburo , Shimozato Yasuyuki , Hayashi Hisaharu , Nakamura Junko 
Published: July 2006

Abstract
Triplet-triplet absorption, phosphorescence, and ESR spectra have been measured on the 1,3,5-tricyanobenzene complexes with toluene, mesitylene, durene, and hexamethylbenzene. Four triplet-triplet absorption bands were commonly observed in the wave number region of 10000–30000 cm−1 for all the complexes. The observed phosphorescence and T-T absorption spectra could be understood systematically by considering the interaction among zero-order charge-transfer triplet states and zero-order locally (within the acceptor) excited triplet states. From an analysis of the zero-field splitting values obtained from the observed ESR spectra, the contribution of the zero-order charge-transfer triplet state to the lowest triplet state was determined to be 76,65,25, and 9% for the 1,3,5-tricyanobenzene complexes with hexamethylbenzene, durene, mesitylene, and toluene, respectively. From the consideration on the results obtained for various polycyanobenzene complexes, the phosphorescence lifetime was found to decrease remarkably for the complexes with the charge-transfer character higher than 50% in their lowest triplet states.
Metachromasy. II. Interaction between Sodium Polyphosphates and Crystal Violet with Special Emphasis on the Effect of Chain Lengths of the Polymer on the Metachromasy Band
Authors: Yamaoka Kiwamu , Takatsuki Mineo , Yaguchi Kunio , Miura Masaji 
Published: July 2006

Abstract
The interaction of crystal violet with sodium polyphosphate in aqueous solutions at neutral pH has been investigated by means of visible absorption spectroscopy and electric conductivity. The mixing ratio of polymer residue to dye was varied from 0.1 to 10000. The metachromasy band at 506 nm was found to fully develop between 3 and 10, whereas conductometric titration showed that crystal violet saturates the polymer site. Emphasis was placed on the effect of the polymer chain length on the metachromasy band. To study this effect, 17 fractionated and 13 refractionated polymer samples with degrees of polymerization extending from 4 to 300 were utilized. A critical range of the degree of polymerization from the metachromasy band exists between 7 and 20. The effect of small ions on metachromasy was also studied using sodium phosphates. An increase in Na+ ions tends to suppress the metachromasy band. This effect is more pronounced with shorter polymer lengths. In order to explain the observed metachromasy phenomena, two mechanisms were postulated; one attributes metachromasy to the flexibility of the polymer backbone when dye is present, and the other deals with specific interaction of dye and polymer site.
Dielectric Relaxation and Molecular Structure. X. Dielectric Behavior of 2-Propanol, 2-Methylpropanol, and 2-Butanol in a Variety of Solvents
Authors: Koshii Taro , Arie Eiji , Nakamura Masahiko , Takahashi Hiroaki , Higasi Keniti 
Published: July 2006

Abstract
The dielectric constants and losses of 2-propanol and its mixtures with benzene, chlorobenzene, 1,4-dioxane or pyridine and 2-methylpropanol or 2-butanol and their mixtures with benzene or pyridine have been measured in the frequency range of 0.35–2.1 GHz at 25.0 °C. Concentrations of alcohols are 1–0.6 mol fractions of the mixtures. The principal relaxation times and the Kirkwood correlation factor g were evaluated. Variation of the principal relaxation times against the concentrations of these branched alcohol mixtures is not much different from that of normal alcohol mixtures. The g factor decreases almost monotonously with increasing amount of solvent exception being found in case for propanol–benzene mixtures.
Vibrational Structures in the He(I) Photoelectron Spectra of Carboxylic Acids
Authors: Watanabe Iwao , Yokoyama Yu , Ikeda Shigero 
Published: July 2006

Abstract
The first and the second bands of the photoelectron spectra of acetic, propionic, and isobutyric acids were recorded, and the vibrational structures in the spectra were studied by comparing with the results of formic acid. The first band exhibits a νc=o, a δOH, and a ρCOOH vibrational progression, and this implies that an oxygen lone pair orbital, from which the first band of the spectra originates, contributes not only to a C=O bonding and the bonding between carbonyl oxygen and hydroxyl hydrogen, but to the settling of carboxyl group in the molecular plane. The second band exhibits a νc=o, a νc-o vibrational progression with very high frequency for the νc=o as observed in the case of formic acid. Thus the vibrational features of the second band are consistent with the ionization of an antisymmetric π orbital localized mainly on carbonyl and hydroxyl oxygen atoms. Since the 0-0 vibrational transitions for the second ionization are out of the Franck-Condon region, the second adiabatic ionization potential was estimated by comparing the vibrational fine structures of the spectra with that of formic acid. The second adiabatic ionization potential of acetic acid so determined is 11.63 eV.
Molecular Structure of Formamide as Studied by Gas Electron Diffraction
Authors: Kitano Mitsuo , Kuchitsu Kozo 
Published: July 2006

Abstract
The structure of formamide HCONH2 has been determined by gas electron diffraction. The rotational constants determined in previous microwave studies have also been used for determining the hydrogen parameters. From a joint least-squares analysis of the diffraction intensity and the rotational constants, where the out-of-plane vibrations are treated as finite-amplitude motions in the corrections for vibrational effects, the following rg bond distances and rz angles have been derived: C–N=1.368±0.003 Å, C=O=1.212±0.003 Å, ∠N–C=O=125.0±0.4°, N–H(average)=1.027±0.006Å, C–H=1.125±0.012 Å, ∠C–N–H(cis to C=O)=118.7±1.0°C, and ∠C–N–H (trans to C=O)=119.7±1.0°, where the uncertainties represent estimated limits of experimental error. The C–N bond is about 0.07 Å longer, whereas the C=O bond is about 0.04 Å shorter, in the free molecule than in the crystal studied by X-ray diffraction. The C–N and C=O bonds are about 0.01 Å or more shorter, and the N–C=O angle is about 3°C larger than the corresponding parameters in acetamide and N-methylacetamide.
Some Electrophilic Substitution Reactions of 2-Hydroxyazulene Derivatives
Authors: Nozoe Tetsuo , Asao Toyonobu , Oda Masaji 
Published: July 2006

Abstract
The bromination, chlorination, and nitration of 1,3-disubstituted 2-hydroxyazulenes were investigated. Bromination by bromine or NBS afforded 1-bromoazulan-2-one derivatives as kinetically-controlled products and 6-bromo-2-hydroxyazulene derivatives as thermodynamically-controlled products. Ghlorination by NCS gave 1-chloroazulan-2-one derivatives, while that by chlorine afforded further chlorine addition products. Nitration afforded a mixture of 1-nitroazulan-2-one and 6-nitro-2-hydroxyazulene derivatives. The ultraviolet, infrared, and NMR spectra of the products were discussed.
Studies of Peptide Antibiotics. XXX. Syntheses of Gramicidin S Analogs Containing N-Methylleucine in Place of Leucine
Authors: Sugano Hiroshi , Abe Hayao , Miyoshi Muneji , Kato Tetsuo , Izumiya Nobuo 
Published: July 2006

Abstract
Two analogs of gramicidin S, cyclo(–Val–Orn–Leu–d-Phe–Pro–Val–Orn–MeLeu–d-Phe–Pro–), i.e., [3-N-Methylleucine]–gramicidin S, and cyclo(–Val–Orn–MeLeu–d-Phe–Pro–Val–Orn–MeLeu–d-Phe–Pro–), i.e., [3,3′-di-N-Methylleucine]–gramicidin S, were prepared in an attempt to investigate the contribution of the NH group of the leucine residue with regard to antibacterial activity. These analogs were almost as active as gramicidin S in the antibacterial test in reaction to microorganisms. The optical rotatory dispersions of these two analogs and of gramicidin S were measured in solvents of ethanol and 8 M aqueous urea. These studies suggested that both of the analogs containing N-methylleucine have a molecular conformation very similar to that of gramicidin S, and that the NH group of the leucine residues is not necessary for stabilizing the conformation in order to exhibit the biological properties.
Effect of Pressure on the Rate of Solvolysis. Formolysis of 1-(p-Substituted benzyl)ethyl Tosylates
Authors: Sera Akira , Yamagami Chisako , Maruyama Kazuhiro 
Published: July 2006

Abstract
The effect of pressure on the formolysis of 1-(P-substituted benzyl) ethyl tosylates was investigated, and the activation volumes, ΔVo\eweq were estimated. The apparent values of activation volume were found to correlate nicely with σ*. Because the present substrates were believed to be formolyzed through two separate processes, anchimerically assisted (kΔ) and unassisted (ks), the apparent values of activation volume were partitioned into the corresponding activation volumes, ΔVΔ\eweq and ΔVs\eweq. The dependence of ΔVΔ\eweq and ΔVs\eweq on the substituents was examined, and the correlation between the mechanisms of solvolysis and ΔVΔ\eweq and ΔVs\eweq was discussed.
Carbon-13 Nuclear Magnetic Resonance Studies of Biphenyl Derivatives II. FT–NMR of Halobiphenyls
Authors: Imanari Mamoru , Kohno Masahiro , Ohuchi Muneki , Ishizu Kazuhiko 
Published: July 2006

Abstract
The natural-abundance 13C NMR spectra of the ortho- or the para-halobiphenyls were obtained by the pulse Fourier transform NMR (FT-NMR). For the para-derivatives, the observed chemical shifts of the C1 C2, and C3-positions gave an excellent linear dependence on the electronegativity of the substituents. The dependence for the C4-position, which showed a deviation from the linear plot, may be due to the heavy atom effects. The additivity of the chemical shifts holds also for the ortho-derivatives except for the cases of the bridgehead carbons, the C1 and C1′-positions. In particular, the observed chemical shifts of the C2, C3, and C4 positions for 2,2′,6,6′-tetrachlorobiphenyl showed a good agreement with the predicted values, whereas a large discrepancy can be seen between the observed and the assumed values for the C1 and C1′ positions. The effects on the chemical shifts due to the steric hindrance are discussed by comparison with the results of the hindered alkylbiphenyls. The temperature dependence of the spin-lattice relaxation time was investigated for 4,4′- and 2,2′-dichlorobiphenyls. The activation energies of the molecular reorientation are negligibly small at the C1 and C4-positions for the para-derivative, but the ortho-derivatives have higher values at these positions, indicating anisotropy for the molecular motion.
The Effect of Copper(II) on the Formation and Thermal Change of Synthetic β-FeOOH
Authors: Inouye Katsuya , Imamura Hiroyuki , Kaneko Katsumi , Ishikawa Tatsuo 
Published: July 2006

Abstract
The effect of Cu(II) added to β-FeOOH in various ratios up to 6% Cu/Fe was examined by X-ray diffraction, electron microscope, BET surface area, DTA, TGA and chemical analyses. Differing from other cases reported previously, Cu(II) showed no effect, but thermal changes of the Cu-doped samples indicated a reinforcement of bonding by Cu.
Studies on Preparation of High Purity Sulfur. II. Removal of Trace Amounts of Selenium and Tellurium in Sulfur by Means of Distillation with Silver
Authors: Suzuki Hiroshi , Osumi Yasuaki , Nakane Masanori , Miyake Yoshizo 
Published: July 2006

Abstract
In the distillation without silver, most of the selenium and tellurium in crude sulfur appeared in the distillate. However, these impurities were removed by distillation using a column which was filled with silver and heated at 600–700 °C. The removal of them in the process was confirmed in a tracer experiment.