bluuebunny/crossref_metadata_2025 huggingface dataset:
Emission Spectra of Benzene, Toluene, and Xylenes by Controlled Electron Impact
Authors: Ogawa Teiichiro , Tsuji Masaharu , Toyoda Minoru , Ishibashi Nobuhiko
Published: July 2006

The emission spectra of gaseous aromatic hydrocarbons under electron impact excitation (60–300 eV) were measured in the 220–450 nm region at very low pressures. A characteristic band was observed in all cases in the 240–340 nm region; this band was assigned to the transition from the lowest excited singlet state to the electronic ground state. Photoemissions from the fragment species, such as H (Balmer series) and CH (A→X, B→X), were also observed. The excited species were concluded, from the relations of the emission intensities to the electron-beam current and to the gas pressure, to be produced by one-electron processes. The relative intensity and the vibrational structure of the observed spectra were examined and compared with those of the fluorescence spectra produced by photo-excitation.
The Crystal Structure of Cinchomeronic Acid
Authors: Takusagawa Fusao , Hirotsu Ken , Shimada Akira
Published: July 2006

The crystal structure of cinchomeronic acid (3,4-pyridinedicarboxylic acid) has been determined by the method of X-ray diffraction. The crystals are orthorhombic, with a space group of P212121, and with cell dimensions of a=11.211, b=11.206, and c=5.285 Å. The structure was determined by the method of symbolic addition. The final R value was 5.90% for 828 observed reflections. The molecule takes the form of a zwitter ion in the crystal. The pyridine ring has, approximately, the C2v symmetry. One carboxyl group consists of C=O and C–O (H) groups, while the other consists of two O(Remark: Graphics omitted.)O groups. These carboxyl groups twist out of the plane of a pyridine ring by 39.6° and 73.0° respectively. The hydrogen bonds are in the forms of two spirals around the two-fold screw axes parallel to the c axis, thus linking the molecules three-dimensionally. There are four molecules per turn of the spiral along the c axis. The carbonyl oxygen atom O(2) is free from the hydrogen bond, while the nitrogen atom N(l) in the pyridine ring participates in it. The relations between the C–N–C bond angle of the pyridine ring and the N···H distance, and also between the net charge on the nitrogen atom calculated by the “complete neglect of differential overlap” (GNDO) method and the O···N distance for a hydrogen bond are discussed in connection with five pyridine-carboxylic acids.
Catalysis of Manganese Salts in the Autoxidation of Cyclohexanone
Authors: Kamiya Yoshio , Kotake Masayoshi
Published: July 2006

The rate of oxidation of cyclohexanone catalyzed by manganese salt increases remarkably in the presence of acetic acid, and is about one hundred times as high as the limiting rate of oxidation kp2(RH)2/2kt. However, manganese concentration does not affect the rate of oxidation much in a wide range. The oxidation of cyclohexanone by manganic ion should be the rate determining step, since the rate of oxidation, which is of first order in cyclohexanone but independent of manganous ion, corresponds to the rate of oxygen absorption of cyclohexanone with the same manganese concentration. The oxidation of cyclohexanone by manganic ion seems to proceed through enol intermediates, since the rate of oxidation increases in the presence of alkali acetates. The rate equation including enolization step and the subsequent oxidation of enol intermediate with manganic ion agrees with the experimental results. A remarkable synergistic effect of metal salts was observed in a mixture of manganese and cobalt. The oxidation products were also analyzed and discussed.
Synthesis and Substitution of 1,3,4,6-Tetra-substituted-3,6-dihalogeno-2,5-piperazinediones
Authors: Yoshimura Juji , Sugiyama Yuichi , Nakamura Hiroshi
Published: July 2006

Addition of chlorine to 3,6-dimethylene- (3) and 3,6-dibenzylidene-1,4-dimethyl-2,5-piperazinediones gave isomers of the corresponding tetrachloride, and substitution of 1,3,4,6-tetramethyl-2,5-piperazinedione with bromine also gave tetrabromide (2) of the same type via successive elimination and addition reactions. Treatment of 2 with water and with methanolic sodium acetate gave the corresponding 3,6-dihydroxy and dimethoxy derivatives, respectively, while treatment with sodium iodide, sodium sulfide, sodium thiocyanate, or sodium thioacetate gave only 3 and sulfur in a good yield. Similar results were obtained in the case of octahydro-5H,10H-dipyrrolo[1,2-a: 1′,2′-d]pyrazine-5,10-dione. However, bromination of 6,13-dioxo-6a,7,13a,14-tetrahydro-6H,13H-pyrazino[1,2-a: 4,5-a′]diindole gave rise only to aromatization. Configurations of the isomers obtained and the reaction processes were discussed.
Conformations of Prolyl Residues in Oligopeptides
Authors: Ashida Tamaichi , Kakudo Masao
Published: July 2006

The structures of the prolyl residues as found in the crystals of various oligopeptides were studied, and a few interesting structural features were found, (i) The Cα–C′–N angle of the peptide group formed by the N atom of the pyrrolidine ring and the Cα and C′ atoms of the preceding residue is widened to about 118° from the usual value of 114° due to the steric repulsion between the Cα and the two hydrogen atoms bonded to the Cδ atom of the pyrrolidine ring, (ii) The Cγ atoms of some pyrrolidine rings have some sort of disorder, and the Cβ–Cγ and Cγ–Cδ bonds seem to be shortened and the Cβ–Cγ–Cδ angles seem to be widened than usual, (iii) Almost half of the pyrrolidine rings have an approximate C2 (half-chair) symmetry, the twofold axis passing through the N atom and the midpoint of the Cβ–Cγ bond. The others have an approximate Cs (envelope) symmetry, the mirror plane passing through either the Cβ or Cγ atom with equal probabilities. In this case the NCαCαCγCδ or NCαCβCδgroups are almost planar, respectively, (iv) The conformation of Cγ-exo against the C′ atom bonded to the Cα atom is mainly found in the residues having the α-helix type torsion angles, while the Cγ-endo is in those having the collagen type torsion angles.
X-Ray Photoelectron Spectroscopy of p-Benzoquinone, Hydroquinone and Their Halogen-Substituted Derivatives
Authors: Ohta Toshiaki , Yamada Masamichi , Kuroda Haruo
Published: July 2006

X-Ray photoelectron spectra of p-benzoquinone, chloranil, bromanil, iodanil, hydroquinone, tetrachlorohydroquinone and chloranilic acid were observed by using the samples freshly deposited in the high vacuum of the spectrometer. The chemical shifts of C ls and O ls levels determined from the XPS spectra are compared with the chemical shifts predicted according to the electrostatic potential model by use of the charge distributions calculated by CNDO/2 method. The charge distributions in the quinone derivatives are successfully estimated by using the observed binding energies of C ls and O ls levels.
Change from Metastable Cubic to Stable Tetragonal Form of Submicron Barium Titanate
Authors: Naka Shigeharu , Nakakita Fumihiko , Suwa Yoshiko , Inagaki Michio
Published: July 2006

The change from metastable cubic to stable tetragonal form was investigated on the submicron BaTiO3 which was prepared by the hydrolysis of titanium tetraisopropoxide in barium hydroxide solution and by crystallization in the glass of BaO–TiO2–SiO2–Al2O3 system. The precipitated BaTiO3 was found to be the aggregates of minute grains of about 100 Å, to have large amount of strain and to absorb about 6% of OH and alcoholic radicals, some of them absorbed chemically. It is in a metastable cubic form. After the heating above 800 °C, it changed to stable tetragonal form in association with weight loss and decrease in lattice strain. The samples heated at 800–900 °C did not show the Curie point on the DTA curve although they were tetragonal. The samples heated at 1300 °C had the Curie point about 122 °C. The glass-devitrified BaTiO3 was also cubic and had large lattice strain. In order to change to tetragonal form, the heating above 1000 °C was needed. The metastable cubic form of submicron BaTiO3 seemed to be stabilized by the absorbants on the surface which balanced with large amount of strain in the lattice.
Photoreactions of Heteroaromatic Compounds. IV. Solvent and Acidity Dependence of the Photoreactions of Nicotinic Acid and Its Derivatives
Authors: Takeuchi Fumikatsu , Sugiyama Tom , Fujimori Takako , Seki Kazuhiko , Harada Yoshiya , Sugimori Akira
Published: July 2006

Nicotinic acid and its derivatives show manifold photoreactivity depending on the solvent and the acidity of the solution. The cationic form of these compounds in general undergoes photo-hydroxylation in aqueous solutions, and photo-ethylation in ethanol solutions. The anionic form of nicotinic acid is resistant to UV-irradiation in strongly alkaline aqueous solution, but undergoes photo-decarboxylation in alkaline ethanol solution. Nicotinic acid yielded 2-(3-pyridyl)-5-pyridinecarboxylic acid in aqueous solutions at pH=4–6. Photo-substitution by 1-hydroxyethyl group occurs in the neutral forms of 3-cyanopyridine and ethyl nicotinate in ethanol solution. The photoreactivity of nicotinic acid is considered on the basis of CNDO/2 calculation.
Mass Spectrometric Study of the Primary Processes in Photochemical Reactions. II. Mass Spectra of Methyl and Ethyl Radicals
Authors: Yamashita Shigeru
Published: July 2006

The mass spectra of methyl and ethyl radicals have been determined by the photolyses of methyl and ethyl iodide using a high intensity light beam and a collision-free photochemical reactor incorporated in the ion-source of a mass spectrometer. The parent ion peak was the most intense in the mass spectra of methyl and of ethyl radicals. Fair agreement was found between the present work and the result obtained by previous workers for pyrolytically produced methyl radicals.
Conditions for the Formation of Fe3O4 by the Air Oxidation of Fe(OH)2 Suspensions.
Authors: Kiyama Masao
Published: July 2006

The optimum conditions were studied for the formation of Fe3O4 by the air oxidation of Fe(OH)2. The suspensions obtained by mixing NaOH and FeSO4 solutions in various values of R(=2NaOH/FeSO4) were subjected to oxidation with air at various temperatures. The oxidation products were then examined by X-ray powder diffraction, chemical analysis, electron microscopic observation, and BET surface-area determination. Fe3O4 is formed at higher temperatures than is FeOOH. The temperature of formation becomes low as R approaches 1.0. In neutral suspensions (R<1), Fe3O4 is formed via green rust II or a mixture of green rust II and Fe(OH)2. By further oxidation, the Fe3O4 formed gradually changes to γ-Fe2O3. A mixture of α-FeOOH and either NaFe3(OH)6(SO4)2 or α-Fe2O3 is formed as the final oxidation product. In alkaline suspensions (R>1), Fe3O4 is formed directly. The morphology and ferrous-ion content of Fe3O4 powder change considerably with the presence of green rust II before the formation of Fe3O4. It is suggested that Fe3O4 is formed near the surface of the particles of Fe(OH)2 and green rust II by the coprecipitation of ferrous ions with ferric hydroxo-complexes.
Binuclear Metal Complexes. IX. Syntheses and Magnetic Properties of Copper(II) and Nickel(II) Complexes of Schiff Bases Derived from 3-Formylsalicylic Acid and Alkyl Amines
Authors: Tanaka Mitsunori , Okawa Hisashi , Tamura Tomoko , Kida Sigeo
Published: July 2006

Copper(II) and nickel(II) complexes of H2fsac-R have been synthesized, where H2fsac-R denotes the Schiff bases prepared from 3-formylsalicylic acid and alkylamines (alkyl(R)=methyl, ethyl, hydroxyethyl, n-propyl, n-butyl, isobutyl, and sec-butyl). On the bases of elemental analyses, IR spectra, visible spectra and cryomagnetic measurements, it was found that the complexes have a binuclear structure connected by two phenolic oxygens; the complexes are abbreviated to M2(fsac-R)2. The nickel(II) complexes contain two, three or four molecules of coordinated water. The cryomagnetic data for Cu2(fsac-R)2 are interpreted in terms of the Bleaney-Bowers equation with large −2 J values (>700 cm−1), indicating the presence of strong intramolecular antiferromagnetic spin-exchange interactions. The Ni2(fsac-R)2·nH2O obey the Curie-Weiss law, the Weiss constants being estimated to −35–−41 K.
The Iodination of Benzene with Iodine in the Thallium(III) Trifluoroacetate-Trifluoroacetic Acid System
Authors: Ishikawa Nobuo , Sekiya Akira
Published: July 2006

Molecular iodine in the system of thallium(III) trifluoroacetate-trifluoroacetic acid has been found to possess a high potency for aromatic iodination. Under controlled conditions, benzene and also mesitylene were stepby-step mono-, di-, and triiodinated, whereupon whole iodine was consumed for the iodination by the oxidation process of the thallium(III) salt. In the course of the iodination of benzene, an intermediate has been revealed to consist of thalliated benzenes, which were transformed into iodinated benzenes by the electrophilic attack of iodine.
Asymmetric Hydroformylation of Styrene. The Effects of the Reaction Conditions on the Stereoselectivity
Authors: Tanaka Masato , Watanabe Yoshihisa , Mitsudo Take-aki , Takegami Yoshinobu
Published: July 2006

The effects of the reaction conditions on the asymmetric hydroformylation of styrene with rhodium catalysts have been studied. The [α]d value and the configuration of the product, hydratropaaldehyde, were much affected by the phosphine/rhodium ratios, the reaction temperatures (20–110 °C), and the partial pressures of carbon monoxide and hydrogen (10–100 atm). The results were mainly explained in terms of the structures of the catalysts and the skeletal isomerization of acyl complexes. The predominant species of the catalysts and the participation of π-benzyl-type intermediate were also discussed.
Formation of Charge-transfer Complexes by Solid State Reaction; Electronic Spectra and Relative Reactivity
Authors: Sato Hiroyasu , Yasuniwa Tamiharu
Published: July 2006

Formation of charge-transfer complexes by solid state reaction was studied for 16 donors and 10 acceptors. The relative reactivity of 160 pairs was determined by the presence or absence of the charge-transfer band on grinding the component pairs of the same concentration (diluted with sodium chloride) for the same length of time. Equilibrium was not reached within the grinding time. This relative reactivity was compared with and found to have a parallel relationship with the relative ease of formation of the charge-transfer complex on evaporating a mixture of the solutions of components, indicating that the relative reactivity is related to an apparent equilibrium established on the grain surface. Relative reactivity was found to be largely dependent on molecular size and geometry. Smaller molecules were more reactive. For molecules with the same number of rings, those with compact structure were more reactive. Most of the new bands given by the reaction were CT bands of microcrystals. They were very broad. A fairly good linear relationship was found between the transition energies of the CT bands and the ionization potentials of the donors or the electron affinities of the acceptors.
The Crystal and Molecular Structure of Tris(π-cyclopentadienyl nickel) tertiary-butylammonium
Authors: Kamijyo Nagao , Watanabé Tokunosuké
Published: July 2006

The crystal structure of tris(π-cyclopentadienylnickel)tertiary-butylammonium, t-C4H9N(π-C5H5Ni)3, has been determined from single crystal X-ray diffractometer data. The space group is C2/c and the lattice constants are a=28.40 Å, b=9.16 Å, c=15.28 Å, β=100°30′, and Z=8. The refinement was carried out using block-diagonal least-squares calculation including anisotropic temperature factors for the three nickel atoms. The final R index for 1620 reflections is 0.138. The molecule is of approximately a trigonal pyramidal structure with an apical nitrogen atom on a triangle of the nickel atoms. The interatomic distances are 2.33–2.39 Å for nickel to nickel, 1.93–1.98 Å for nickel to nitrogen. The distances between a nickel atom and a centroid of a cyclopentadienyl ring are 1.74–1.81 Å. The three cyclopentadienyl rings are inclined to the nickel triangle plane at 68°–69°.
Effect of pH on the Circular Dichroism(CD)-sensitive Transitions of Some Lanthanoid(III) Complexes and “Pseudo CD-sensitive Transitions” of Europium(III) and Terbium(III) Complexes
Authors: Misumi Seizo , Isobe Toshiyuki , Furuta Haruko
Published: July 2006

The effect of pH on the CD-sensitive transitions of lanthanoid(III) complexes with l-propylenediaminetetraacetic acid(l-PDTA) and l-ethylenediaminedisuccinic acid(l-EDDS) was studied. The relation between the cross-over pH where the CD pattern changes or sign of CD reverses and the number of 4f-electrons in lanthanoid(III) complexes with l-EDDS showed a tetrad curve. A strong evidence for coordination of hydroxide ions was suggested. “Pseudo CD-sensitive bands” in the spectra of the complexes of europium(III) and terbium(III) which do not obey the selection rule ΔJ≤1 were found, and the mechanisms of these transitions were elucidated.
SORPTION OF VAPOUR BY CHABAZITE
Authors: Baba Tositomo
Published: July 2006

1. The sorption amounts and velocities by chabazite of fifteen substances have been measured at 25.0°C. by a statical method.

2. The sorption amounts of the vapours of pentane, benzene, ether, chloroform, carbon tetrachloride, acetone, and ethyl acetate have been found to be negligibly small, while those of methyl alcohol, methyl amine, carbon dioxide and carbon bisulphide have been found to be great. Ethyl alcohol, ethyl amine, propyl amine and butyl amine have been slightly sorbed.

3. No change in appearance of the mineral has been observed by the first sorption of alcohols, amines and carbon dioxide, but in the case of carbon bisulphide the crystal of chabazite have becomes yellow in colour, probably indicating catalytic decomposition of this vapour into free sulphur, hydrogen sulphide and other decomposition products.

4. By the repeated sorptioas of methyl amine, methyl alcohol and ethyl alcohol, the crystals of chabazite have become more or less fragile, and by heating and evacuating these fragile crystals have disintegrated themselves into fine powders.

5. The vapours which have large molecular volumes are generally difficult, if not impossible, to be sorbed by chabazite. The large gaps in sorption amounts between methyl and ethyl compounds in alcohol and amine series may be attributed to the same reason.

6. With regard to the sorption velocities of alcohols, the following formula has been applied which has some theoretical meaning:

(Remark: Graphics omitted.)

where x is the sorption amount at time t, and a, b, k and h the empirical constants.
ATOMIC HYDROGEN OCCLUDED IN IRON NITRIDE
Authors: Satoh Shun-ichi
Published: July 2006

The author confirms the existence of atomic hydrogen in iron nitride:

(1) By the presence of hydrogen when heating iron nitride above 430°C. at which iron nitride is found to decompose slowly.

(2) By the measurement of the single potential of iron nitride in the normal ferrous sulphate solution.

(3) By the oxidation of atomic hydrogen due to oxygen in the water in which iron nitride is immersed.

(4) By the transformation of potassium ferricyanide into potassium ferrocyanide by atomic hydrogen occluded in iron nitride.

By measuring the single potential of nitrided iron, he observed the change of compact iron into porous iron by nitriding.

The influence of light on the single potential of iron nitride was tested and it was found that light produces no marked photo-chemical effect upon it.
Spectroscopic and Equilibrium Dialysis Studies of the Poly(acrylic acid)–Cu(II) Complex in the pH Range 3.5–7
Authors: Yamaoka Kiwamu , Masujima Tsutomu
Published: July 2006

The complex formation between poly(acrylic acid), poly(Acr), and Cu2+ ion was studied in 150 mM NaCl solutions at 25 °C and at the mixing ratios of Acr residues-to-Cu2+, R, of 32, 16 and 8, in the pH range of 3.5–7 by the spectroscopic and equilibrium dialysis methods. The dialysis results showed that more than 90% of the Cu2+ ions remain bound to the polymer at pH’s higher than 4.5, but the bound Cu(II) begins to dissociate at lower pH values. The data also revealed that the true absorption spectra of poly (Acr)–Cu(II) complexes varied with pH and R in a complicated manner. The analysis of the bound Cu(II) spectra disclosed the presence of three different kinds of Cu(II)–Acr complexes over the entire pH range. It is the relative amounts of these three complexes that vary with pH and R. With a newly devised plot of the dialysis data, the stability constant for each Cu(II)–Acr complex was determined. In the poly(Acr)–Cu(II) macrocomplex, each Cu(II) was estimated to bind to two or four carboxylato ligands.
Oxidation-reduction Equilibrium between Anion Radicals. Electron-accepting Property of 2,3-Dichloro-5,6-dicyano-p-benzoquinone
Authors: Iida Yôichi
Published: July 2006

The electron affinity and the oxidation-reduction potential of 2,3-dichloro-5,6-dicyano-p-benzoquinone were estimated by means of the equilibrium constant of the preferred electron transfer reaction between anion radicals in acetonitrile solution.
Nucleophilic Ion Pairs. 6. Catalytic Hydrolysis of p-Nitrophenyl Acetate by Zwitterionic Hydroxamate Nucleophiles in Representative Micellar Systems
Authors: Kunitake Toyoki , Okahata Yoshio , Tanamachi Shoichi , Ando Reiko
Published: July 2006

Several surfactant-like zwitterionic hydroxamates were synthesized and their reactions with p-nitrophenyl acetate were studied in water in comparison with those of simple, anionic hydroxamates. The zwitterionic hydroxamates showed enhanced reactivities in cationic, zwitterionic and nonionic micelles: 20–100 times relative to the nomicellar rate at pH 8.9, 30 °C. The rate enhancement was attributed to lowered pKa values and to activation of the hydroxamate anion in the hydrophobic domain. The rate was suppressed in an anionic micelle because of the enhanced pKa value. Deacylation of the acetyl hydroxamate intermediate was hydroxide-catalyzed. The enhanced reactivity of the zwitterionic hydroxamate in organic media was less sensitive to the water concentration than that of the hydroxamate ion pair. These results can be explained in terms of “hydrophobic ion pair.”
A Rapid Esterification by Means of Mixed Anhydride and Its Application to Large-ring Lactonization
Authors: Inanaga Junji , Hirata Kuniko , Saeki Hiroko , Katsuki Tsutomu , Yamaguchi Masaru
Published: July 2006

A rapid and mild esterification method using carboxylic 2,4,6-trichlorobenzoic anhydrides in the presence of 4-dimethylaminopyridine was developed. The method was also successfully applied to the synthesis of large-ring lactones, including Dl-2,4,6-tridemethyl-3-deoxymethynolide.
Both Oxidation and Reduction of Aromatic Hydrocarbons by an Electrolysis Cell Designed for Low-temperature ESR Studies
Authors: Ohya-Nishiguchi Hiroaki
Published: July 2006

A simple two-electrode cell for low-temperature electron spin resonance (ESR) measurements has been designed. A helical gold wire, the working electrode with large surface area (12 cm2), generated intra muros enough positive or negative ions to measure the ESR spectra of unstable radical ions at low temperatures. To test the electrolysis conditions of the cell, the ESR spectra of about 20 aromatic compounds have been observed at temperatures as low as −90 °C. It has been shown that the cell can be applicable to the compounds with half-wave potential of 1.5 to −3.7 V SCE, provided that the ions produced are not reactive. The experimental conditions of the dimer cation generation have also been checked in polar or nonpolar solvents.
An Alternative Method of Solving the Rose-Drago Equation for the Determination of Equilibrium Constants of Molecular Complexes
Authors: Seal Bejoy K , Mukherjee Ashok K , Mukherjee Dulal C
Published: July 2006

An alternative method for solving the Rose-Drago equation for the determination of equilibrium constants of molecular complexes has been developed. It yields well-defined K values even for certain systems in which the Rose-Drago procedure for solving the R-D equation is not satisfactory. Our method is based on the transformation of the Rose-Drago equation into one involving three variables and using two linear plots. In applying the method to a wide variety of experimental data, the calculated values of the equilibrium constant have been found to be in excellent agreement with those computed by the well-known iterative procedure. With good data, the calculated values are in good agreement with those from the Benesi-Hildebrand or some other modified plots.
Pre-exponential Factor in Semiconducting Vitamin A (Alcohol and Acetate)
Authors: Mallik Biswanath , Ghosh Alpana , Misra T N
Published: July 2006

The semiconductive properties of vitamin A (alcohol and acetate) on adsorption of various vapors have been studied. The adsorbed vapors increase the semiconduction currents by several orders of magnitude and decrease the semiconduction activation energies. Such change depends on the chemical nature and also on the amount of vapor adsorbed. Semiconducting vitamin A follows the three-constant equation

σ(T)=σ0′exp(E⁄2kT0)exp(−E⁄2kT)

where the conventional pre-exponential factor σ0 has been replaced by σ0′exp(E⁄2kTo) (the so called compensation effect). Here T0 and σo′ are constants for the substance and T0 is called the characteristic temperature. Various methods used for evaluating these constants have yielded consistent results with T0≈402 K and σ0′≈2.8×10−9 Ω−1 cm−1 for vitamin A alcohol and T0≈335 K and σ0′1.5×10−10 Ω−1 cm−1 for vitamin A acetate. Excellent correlation obtained between the relevant parameters in semiconducting vitamin A indicates that σ0 and E are physically related. Various models for conduction mechanism leading to compensation effect have been discussed. The measured activation energies on adsorption of same amount of various vapors show a linear relationship with the ionization potential of the adsorbed molecules suggesting that charge-transfer interaction is responsible for the semiconductivity enhancement.
Nonequilibrium Thermodynamics of Ionic Diffusion Coefficients in Binary Electrolyte Solutions
Authors: Kumamoto Eiichi , Kimizuka Hideo
Published: July 2006

Ionic diffusion coefficients were treated on the basis of nonequilibrium thermodynamics. They were calculated for alkali metal chloride solutions and compared with the experimental data of self-diffusion coefficients.
Scalar Coupling and Spin-rotation Interactions in the 13C Nuclear Magnetic Relaxation of Methyl-d3 Bromide
Authors: Yanagisawa Masaru , Yamamoto Osamu
Published: July 2006

13C NMR relaxation times have been obtained for methyl-d3 bromide at room temperature, from which the spin-spin coupling constant between 13C and 79Br has been extracted and found to be 41.6±2.0 Hz. The contribution of the spin-rotation interaction to the 13C relaxation is large in this molecule. This fact may be attributed to the presence of a methyl rotor, but cannot be satisfactorily interpreted in the framework of the present theories.
A Hydroxyl Proton Magnetic Resonance Study of 2-Cyclohexen-1-ols, 1-Tetralols, 4-Chromanols, and 4-Thiochromanols in Dimethyl Sulfoxide
Authors: Hanaya Kaoru , Kud\={o} Hideaki , Gohke Kazuo , Imaizumi Shin
Published: July 2006

The proton magnetic spectra in dimethyl sulfoxide of 2-cyclohexen-1-ols, 1-tetralols, 4-chromanols, and 4-thiochromanols have been determined. In all cases, the pseudoaxial OH proton resonates at a higher field than the pseudoequatorial one. The spin-spin coupling between the hydroxyl and carbinyl protons is found to be greater for the pseudoequatorial epimer.
A Comparative Study of Nickel and Cobalt Catalysts in the Hydrogenation of Substituted Acetophenones. Dependence of Hydrogenation Rate and Adsorption Strength on Substituents and Solvents
Authors: Kajitani Masatsugu , Suzuki Naoki , Abe Tsutomu , Kaneko Yoshimitsu , Kasuya Kazuhiko , Takahashi Kazunori , Sugimori Akira
Published: July 2006

The difference in the nature of nickel and cobalt catalysts has been investigated by a comparative study of the competitive hydrogenation of substituted acetophenones. The electronic and steric effects of substituents and the effects of solvents on the adsorption strength of acetophenones are greater for the reactions over R-Ni than for those over R-Co. On R-Co catalyst acetophenones substituted with electron attracting groups (3-methoxyl, 3-hydroxyl, and 4-fluoro groups with σ0>0) are adsorbed more strongly than those with electron donating groups (2-, 3-, and 4-alkyl and 4-methoxyl groups with σ0<0). Over R-Ni catalyst the adsorption of acetophenone is greater than that of any substituted acetophenones. The rates of hydrogenation over R-Ni are more susceptible to the effects of substituent and solvent than those over R-Co. Over both R-Ni and R-Co the rates of hydrogenation of unsubstituted acetophenones are greater than those of substituted acetophenones with either electron donating or electron attracting groups.
The Stability of Bis(8-quinolinolato)copper(II)
Authors: Akaiwa Hideo , Kawamoto Hiroshi
Published: July 2006

The IR spectra of the titled and related compounds have been measured, and the stabilities of the chelates characterized by the relative strengths of the metalnitrogen bonds. An explanation has been made by comparing the extraction behavior of Cu(II) and Fe(III) chelates.
Synthesis and Absorption Spectra of 1,4-Diazaanthraquinone Derivatives
Authors: Nakazumi Hiroyuki , Agawa Testuro , Kitao Teijiro
Published: July 2006

A new 5-amino-1,4-diazaanthraquinone and related compounds were prepared from 2,3-dichloro-1,4-naphthoquinone by two different methods. The transition energies and electron densities of 5-amino- 1,4-diazanthraquinone and 1-aminoanthraquinone were calculated by a variable β,γ-modification of the PPP method.
Reactions of 2-Tosyloxy- and 2-Chlorotropones with Hydrazine, Methylhydrazine, and Phenylhydrazine
Authors: Imafuku Kimiaki , Kamachi Katsuya , Matsuda Yasunori , Matsumura Hisashi
Published: July 2006

The reactions of 2-tosyloxytropones or 2-chlorotropones with hydrazine, methylhydrazine, and phenylhydrazine gave 2-hydrazinotropones, 2-(α-methylhydrazino)-tropones, and 2-(β-phenylhydrazino)tropones, respectively. All the reactions are normal substitution at C-2 position of the tropone ring. No ciné reaction was observed. The reactivity of hydrazines decreases in the order: NH2NH2>CH3NHNH2>>PhNHNH2.
Halogenated Sesquiterpene Phenols and Ethers from the Red Alga Laurencia glandulifera Kützing
Authors: Suzuki Minoru , Kurosawa Etsuro
Published: July 2006

Several brominated sesquiterpene phenols and the related ethers were isolated from the red alga Laurencia glandulifera Kützing. The structures of these compounds were determined on the basis of spectroscopic evidence and chemical correlation.
Diels-Alder Reaction of 2-Substituted Tropones with Ethylene. HMO Level Aspect of the Regioselectivity
Authors: Uyehara Tadao , Kitahara Yoshio
Published: July 2006

2-Chloro-, 2-methoxy-, 2-phenyl-, and 2-methyltropones (2,4,6-cycloheptatrien-1-ones) and benzoate of tropolone (2-hydroxy-2,4,6-cycloheptatrien-1-one) reacted with ethylene affording Diels-Alder type 1,4-addition products, bicyclo[3.2.2]nona-3,6-dien-2-ones. The regioselectivities of the cycloaddition are quite random, while they are reproduced by the calculated interaction energies based on Salem’s PMO equation which includes the closed-shell repulsion term.
Preparation of a Rare Earth Ion Selective Electrode
Authors: Takasaka Yoshihiro , Suzuki Yasuo
Published: July 2006

A new rare earth-ion selective electrode with a cerium(IV) oxide membrane has been prepared. The electrode was selective for the trivalent rare earths with a slope as great as 58 mV. The electrode was less selective for bi- and quadrivalent cations.
Reaction of Thiobenzamides with Arylmagnesium Bromides
Authors: Karakasa Takayuki , Hanzawa Takashi , Motoki Shinichi
Published: July 2006

Reactions of thiobenzamide, p-methylthiobenzamide, p-methoxythiobenzamide, and p-chlorothiobenzamide with 4 equivalents of phenyl-, p-tolyl-, p-methoxyphenyl-, and p-chlorophenylmagnesium bromides gave the corresponding diphenylmethyleneamine and thiobenzophenone as 1,2-addition produsts in good yields.
17O Nuclear Magnetic Resonance Studies. V. 17O Shieldings of Some Substituted Anisoles
Authors: Katoh Morimatsu , Sugawara Tadashi , Kawada Yuzo , Iwamura Hiizu
Published: July 2006

Fourier transform 17O NMR spectra have been measured for a number of meta and para substituted anisoles in natural abundance at 10.8 MHz. The shielding of the methoxyl oxygen nucleus decreases as the electron-withdrawing substituents are introduced to the ring. A good linear correlation is obtained for a plot of the 17O shifts versus the Hammett σ− constants.
Circular Dichroism and Stereochemistry of Tetranuclear Cobalt(III) Complexes of Hexol Type. II. Hexakis(ethylenediamine)-hexa-μ-hydroxo-tetracobalt(III) Ion, [Co{(OH)2Co(en)2}3]6+
Authors: Kudo Tomikatsu , Shimura Yoichi
Published: July 2006

The theoretically possible eight optical isomers of hexakis(ethylenediamine)-hexa-μ-hydroxo-tetracobalt(III) ion, [Co{(OH)2Co(en)2}3]6+, were separated by column chromatography, absorption and circular dichroism spectra being measured in the visible and ultraviolet region in 0.01 mol dm−3 HCl and 0.15 mol dm−3 Na2SeO3 solutions. Absolute configurations were determined by means of circular dichroism spectra and the characterization of mononuclear cobalt(III) ions produced by decomposition of the tetranuclear isomers in an acid solution. The additivity of the two main circular dichroism contributions due to the chiral CoO6 and CoN4O2 chromophores is discussed, and the configurational chirality of CoO6 chromophore is expressed by summing up the contributions from three pairs of CoN4O2 chromophores as in the so-called ring-pairing method.
Kinetic Study for the Reaction of (Arylthio)trimethylstannane with Benzoyl Chloride Giving S-Aryl Thiobenzoate.
Authors: Kozuka Seizi , Naribayashi Ikuya
Published: July 2006

A kinetic study has been conducted on the reaction of (arylthio)trimethylstannane with benzoyl chloride giving chlorotrimethylstannane and S-aryl thiobenzoate. The reaction has been found to obey a second order kinetic equation. A mechanism involving bimolecular nucleophilic attack of the sulfur atom on the acyl carbon has been suggested for the reaction based on the substituent effects of arylthio and benzoyl moieties.
Reduction of Transition-metal Salts by N-Propyl-1,4-dihydronicotinamide
Authors: Okamoto Tadashi , Ohno Atsuyoshi , Oka Shinzaburo
Published: July 2006

It was found that N-propyl-1,4-dihydronicotinamide reduces bis(benzonitrile)dichloropalladium, palladium(II) acetate, and chlorides of rhodium(III), platinum(IV), and ruthenium(III) smoothly in organic solvents affording a facile method for the preparation of low valent catalysts in situ.
Synthesis of a Few Derivatives of Cycloiridated 2-(2-Thienyl)pyridine
Authors: Nonoyama Matsuo
Published: July 2006

A few derivatives of cycloiridated 2-(2-thienyl)pyridine were prepared and characterized by infrared and 1H NMR spectra.
The 2:1 Adduct of Chloro[N-(2-dimethylaminoethyl)salicylideneaminato]copper(II) with Chlorides of Copper(II), Manganese(II), and Nickel(II)
Authors: Tokii Tadashi , Kaneko Makoto , Yamanaka Kusuo , Muto Yoneichiro , Kato Michinobu
Published: July 2006

The adducts listed in the title have been prepared, and their trimeric nature confirmed on the basis of elemental analysis and IR and electronic spectra. The magnetic properties of the MnCl2 and NiCl2 adducts have been analyzed in terms of a linear trimer model.
Reaction of Guaioxide with N-Bromosuccinimide and the Preparation of 4,6-Guaiadien-3-one and 1-Epi-4,6-guaiadien-3-one
Authors: Hirota Hiroshi , Moriyama Yoshihiko , Shirasaki Hidekazu , Tsuyuki Takahiko , Takahashi Takeyoshi
Published: July 2006

Treatment of guaioxide with N-bromosuccinimide gave 4-bromoguaioxide, which was dehydrobrominated to yield 3-dehydroguaioxide. The olefin was then converted into 8-deoxytorilolone and 8-deoxy-1-epitorilolone by the known procedures. Dehydration of these deoxy derivatives in benzene in the presence of p-toluenesulfonic acid gave 4,6-guaiadien-3-one and 1-epi-4,6-guaiadien-3-one, respectively.
syn- and anti[3.3](1,4)Naphthalenophanes
Authors: Yoshinaga Minoru , Otsubo Tetsuo , Sakata Yoshiteru , Misumi Soichi
Published: July 2006

The title compounds were prepared by pyrolysis of disulfones. The absorption spectra depend rather on the stacking mode between two naphthalene rings than ring-to-ring distance, whereas for the emission spectra the reverse is the case. A [4+4]photocycloaddition and a reverse reaction were observed between anti-form and its photoisomer.
Reactions of Trimethylsilyl Cyanide and N-(Trimethylsilyl) diphenylmethyleneamine with Nitrones and Thermal Decompositions of Their Adducts
Authors: Tsuge Otohiko , Urano Satoshi , Iwasaki Takahiko
Published: July 2006

Trimethylsilyl cyanide (1) and N-(trimethylsilyl)diphenylmethyleneamine (2) reacted with α-aryl-N-phenyl-nitrones to afford the corresponding 1: 1 adducts 4 and 5 respectively. Thermal decomposition of 4 in refluxing xylene gave azoxybenzene, stereoisomers of 2,3-diarylsuccinonitriles, α-iminonitriles and/or benzanilides, whose yields depended on the nature of substituents on phenyl group of 4. On heating in benzene 5 afforded a mixture of azoxybenzene and meso-N,N′-bis(diphenylmethylene)-1,2-diarylethylenediamines. On the other hand, reactions of 1 and 2 with N-(diphenylmethylene)aniline N-oxide or N-(9-fluorenylidene)aniline N-oxide did not give the corresponding 1: 1 adducts, but instead compounds arising from thermal decomposition of initial 1: 1 adducts were directly obtained. The reaction of 1 with N-(p-diethylaminophenyl)-α-phenylnitrone leading to the corresponding α-imino nitrile is also described.
An Ultrasonic Method for Determination of the Difference in Hard-Sphere Volume of Conformational Isomers
Authors: Aoi Masakatsu , Arakawa Kiyoshi
Published: July 2006

An ultrasonic method for determining the difference in hard-sphere volume of conformational isomers from sound velocity has been worked out, its accuracy being improved by taking the temperature dependence of the effective hard-sphere diameter into account. The difference for 1,2-dibromoethane, 1,1,2-trichloroethane, methylcyclohexane, and 1,2-dichloroethane was determined. The fractions of volume differences ΔV⁄V in these liquids were found to be 4.5, 5, 11, and 19% for 1,2-dibromo-, 1,1,2-trichloroethane, methylcyclohexane, and 1,2-dichloroethane, respectively.
Polymerization of Silicic Acid Adsorbed on Iron(III) Hydroxide
Authors: Yokoyama Takushi , Nakazato Tatsuo , Tarutani Toshikazu
Published: July 2006

Adsorption of silicic acid on iron(III) hydroxide from aqueous solution and polymerization of adsorbed silicic acid were affected by pH, concentration of silicic acid before and after adsorption, or the relative amount of silicic acid and iron(III) hydroxide. The amount of adsorbed silicic acid and the rate of its polymerization were maximum at pH 9. The polymerization reaction of silicic acid on the surface of iron(III) hydroxide was found to consist of two steps: (1) polymerization of adsorbed monosilicic acid and (2) polymerization between monosilicic acid in the solution and silicic acid species already present on the surface of iron(III) hydroxide, giving a three-dimensional gel structure.
Quenching of Excited Zinc(3PJ) and Zinc(1P1) Atoms by Several Gases
Authors: Yamamoto Shunzo , Takei Takashi , Nishimura Norio , Hasegawa Shigeo
Published: July 2006

The intensities of the 307.6 nm and 213.9 nm resonance lines of zinc were measured at different pressures of several gases, and the quenching rate constants were determined on the basis of the Stern-Volmer plots. The quenching cross-sections obtained here were compared with those for mercury and cadmium. The simple chargetransfer curve-crossing theory proposed by Breckenridge and Renlund for the quenching of excited cadmium and mercury atoms by N2, CO, CO2, and so on was found to be useful for the quenching of excited zinc atoms, as well. Isotope effects on the quenching of Zn(3PJ) and Zn(1P1) by H2 and D2 were also discussed.
THE SOLUBILITIES OF THIOCYANATE OF METALS
Authors: Masaki Kosaku
Published: July 2006

(1) The solubilities of lead thiocyanate and cadmium thiocyanate were determined by the potentiometric method.

(2) The solubilities of zinc thiocyanate and cobalt thiocyanate were determined by the measurements of the specific conductances.
CHEMISTRY OF THIO-CHOLINE HALIDE (TRIMETHYL THIO-ETHYL AMMONIUM HALIDE). II NEW THIO-CHOLINE CHLORIDE AND ITS DERIVATIVES
Authors: Harada Taichi
Published: July 2006

1. Chloro-choline chloride was obtained by the condensation of trimethylamine with ethylene chloride. It decomposes slowly above 163°C. melting and boiling, at 242°C. with a reddish brown discoloration.

2. Thio-choline chloride was prepared from chloro-choline chloride by the action of 2-thio uracil at 150°C. Its isoelectric point was found to be at PH 7.0. It decomposes slowly above 200°C. (approximately), melting and boiling at 238°C.

3. Thio-choline chloride reacts with silver chloride to form (Remark: Graphics omitted.) whose solubility in water at 37° was found to be 0.1215 gr. It decomposes slowly above 70°C. (approximately), melting and boiling around 228°C.
Palladium-Catalyzed, Atmospheric Pressure Carbonylation of Allylic Halides under the Influence of Sodium Hydroxide or Alkoxides. A Facile Synthesis of β,γ-Unsaturated Acids
Authors: Okano Tamon , Okabe Nobuyuki , Kiji Jitsuo
Published: July 2006

The palladium-catalyzed, atmospheric-pressure carboxylation of allylic halides occurs readily in an aqueous sodium hydroxide/organic solvents two-phase system, giving β,γ-unsaturated acids. Phosphine complexes [PdCl2L2] (I, L = m-(Ph2P)C6H4SO3Na; II, L = Ph3P) or Na2[PdCl4] (III) can be used as the catalyst. Atmospheric-pressure alkoxycarbonylation is realized under the influence of a homogeneous alcoholic solution of sodium alkoxide. Phosphine-free palladium complexes, such as [(π-allyl)PdCl]2 or III, are the favored catalyst. β,γ-Unsaturated esters are obtained in high yields.
Syntheses of and Restricted Csp3–Csp2 Bond Rotation in Triptycenes That Carry C4-Olefinic Substituent at 9-Position
Authors: Oki Michinori , Taguchi Yasushi , Toyota Shinji
Published: July 2006

Triptycene derivatives that carry C4-olefinic substituents at the 9-position, in which the olefin is connected to C(9) through an sp2 carbon, are synthesized. Their dynamic behaviors, as observed by dynamic NMR technique, are discussed on the basis of the results of MM2 calculations. The barrier to rotation of the olefinic groups is higher when there is a methyl group which directs inside relative to the triptycene skeleton, than the cases where no such a methyl group exists.
Refolding of Trimeresurus flavoviridis Phospholipases A2
Authors: Tsuno Shinji , Ogawa Tomohisa , Nakashima Kin-ichi , Oda Naoko , Lee Sannumu , Shimohigashi Yasuyuki , Aoyagi Haruhiko , Ohno Motonori
Published: July 2006

Trimeresurus flavoviridis (Habu snake) venom contains phospholipase A2 (PLA2) isozymes which are rich in disulfide bond and show diverse activities in spite of their highly homologous structures. When reduced form of Tyr(NO2)-67-PLA2, which is a mimic of Asp-49-PLA2 mutant, was oxidized at pH 8.0 in the presence of 5 mM L-cysteine and 5 mM Ca2+, native form of Tyr(NO2)-67-PLA2 was produced as being judged from both activity regeneration and adequate HPLC profile. Reduced forms of two Lys-49-PLA2 isozymes with extremely low lipolytic activity, which are called basic proteins I and II, also generated native forms of proteins when oxidized under the same conditions as above. Protein disulfide isomerase accelerated proper folding of reduced Tyr(NO2)-67-PLA2 at an initial phase of oxidation and was effective for rearrangement of incorrectly paired disulfide bonds of Asp-49-PLA2 to native construction. However, this isomerase failed to convert reduced form of partially active L-fragment, Asp-49-PLA2 lacking N-terminal octapeptide, to the native form, indicating that the entire sequence of protein in a nascent state is primarily required for proper folding. The present data together with the fact that reduced Asp-49-PLA2 folded properly (S. Tanaka et al. J. Biochem., 96, 1443 (1984)) afforded a strong basis for the structure and function study of T. flavoviridis PLA2s by means of in vitro mutagenesis technique.
Synthesis of 2-(Substituted Methyl)-3,4-Disubstituted Pyrroles and Their Conversion into the Corresponding Porphyrins
Authors: Kinoshita Hideki , Tanaka Shingo , Nishimori Natsu , Dejima Hiroshi , Inomata Katsuhiko
Published: July 2006

2-Hydroxymethyl-1-methylsulfonyl-3,4-disubstituted pyrroles and 2-hydroxymethyl-3,4-disubstituted pyrroles were effectively converted into the corresponding 2-(substituted methyl)pyrrole derivatives by the reaction with various nucleophiles in the presence of base. These products were further transformed to the corresponding porphyrins regioselectively under almost neutral or basic conditions.
The Resolution and Absolute Configuration of 2,3-Methanopyroglutamic Acid, 3-Oxo-2-azabicyclo[3,1,0]hexane-1-carboxylic Acid
Authors: Kodama Hiroaki , Matsui Shinichi , Kondo Michio , Stammer Charles H
Published: July 2006

The resolution of racemic 2,3-methanopyroglutamic acid (∇Glp) was accomplished using L- and D-Leu-NH2 and both isomers were hydrolyzed to give optically active (Z)-2,3-methanoglutamic acids1) (∇ZGlu), respectively. The optical rotations of these samples were compared with ∇ZGlu obtained by hydrolysis of ∇Glp prepared by oxidation of (2S,3R)- or (2R,3S)-2,3-methanoproline1) (∇Pro), the absolute configurations of which were determined by X-ray diffraction earlier. These experiments showed (−)- and (+)-∇Glp to have the (2S,3S)- and (2R,3R)-configurations, respectively.
Enantioface Differentiating Reduction of Keto Acid in the Presence of 6-Deoxy-6-amino-β-cyclodextrin with NaBH4 in Aqueous Media
Authors: Hattori Kenjiro , Takahashi Keiko , Sakai Naoki
Published: July 2006

The formation of an inclusion compound and the interaction of both ionic and hydrogen bonding were shown to be indispensable in the asymmetric reduction of keto acid in the presence of 6-deoxy-6-amino-β-cyclodextrin with NaBH4 in an aqueous buffer solution. Furthermore, multiple interactions were elucidated and the enantioface differentiating reduction was induced in the concerted interactions. A mechanistic scheme for the enantioface differentiating attack of a reducing-reagent on the included substrate was suggested.
Lattice Parameters of Sol–Gel Derived Metastable ZrO2–CaO Solid Solutions
Authors: Yoshioka Hideki
Published: July 2006

Metastable cubic and tetragonal phases in (1−x)ZrO2–xCaO solid solutions (x = 0–0.155) were prepared by the sol–gel method. A sequential phase transition from amorphous to cubic, tetragonal, tetragonal+monoclinic with a rise in treatment temperature was observed for specimens of x = 0.044. The lattice parameter of the metastable cubic phases changed linearly with the composition, indicating that the Vegard’s law can be extended to the metastable phase. The validity of the Vegard’s law and the stability of metastable phases are discussed.
Highly Selective Membrane Transport of Zn2+ Ion by a Cooperative Carrier Composed of 1,10-Diaza-18-crown-6 and Palmitic Acid
Authors: Dadfarnia Shayessteh , Shamsipur Mojtaba
Published: July 2006

A mixture of 1,10-diaza-18-crown-6 and palmitic acid was found to be an excellent cooperative carrier for the uphill transport of Zn2+ ions through a chloroform liquid membrane. In the presence of histidine, as a suitable metal ion acceptor in the receiving phase, it can selectively and efficiently transport Zn2+ ion from aqueous solutions containing other cations such as Na+, K+, Mg2+, Ca2+, Mn2+, Cu2+, Ni2+, Co2+, Hg2+, Pb2+, and Cd2+. Amount of Zn2+ transport across the liquid membrane after 2 h is about 90%, while that of other cations is < 4%.