bluuebunny/crossref_metadata_2025 huggingface dataset:
Improvement of Zone Melting Apparatus. I. Zone Melting Apparatus with a Device to Prevent Breakage of a Sample Tube
Authors: Wakayama Nobuko I , Nakano Yasuko , Mashiko Yo-ichiro
Published: July 2006

A glass sample tube is widely used in zone melting of organic substances since it is transparent, inert to most substances and easily prepared in the laboratory. The glass tube, however, is frequently broken owing to the volume increase of the sample. A new device was worked out to prevent breakage of the sample tube, to purify the sample efficiently and to make replacement of the atmosphere inside the sample tube possible. The apparatus requires much less space than for one ever reported and consists of a sample tube with a set of stainless steel spring and Teflon plug and a new mechanism for carrying it. It was successfully used for biphenyl and p-dichlorobenzene.
Thermoluminescence from the UV-Irradiated Solution of Triphenylmethane at Low Temperature
Authors: Yamamoto Naoto , Matsumura Michio , Tsubomura Hiroshi
Published: July 2006

Triphenylmethane, irradiated in the near ultraviolet region in a non-polar rigid medium at 77 K, showed thermoluminescence consisting of three bands, fluorescence and phosphorescence of triphenylmethane and fluorescence of triphenylmethyl radical. With the increase of solute concentration the yield of the emissions from triphenylmethane decreased while that of the emission from the radical increased. It was concluded that the emissions from triphenylmethane were due to the recombination between triphenylmethane cation and the photoejected electron, and that the fluorescence from the radical was mainly due to the electron transfer reaction between triphenylmethane cation and triphenylmethyl anion. Detailed emission processes inlcuding electron transfer and energy transfer processes were discussed.
Transmission of Substituent Effects through the Oxygen and Sulfur Atoms. IV. CNDO/2 Charge Distributions in Vinyl and Divinyl Ethers and Sulfides
Authors: Kajimoto Okitsugu , Kobayashi Masaru , Fueno Takayuki
Published: July 2006

Charge distributions in vinyl methyl and divinyl ethers and their sulfur homologs bearing a polar substituent at the trans-β position were calculated by the CNDO/2 method. It was found that the effect of substituents on charge distribution is transmitted primarily through the successive π-polarization of the ethylenic units involved. In the divinyl compounds, the sulfur atom on the spd basis is calculated to transmit the substituent effects more effectively than the oxygen atom. The greater transmission efficiency of the sulfur atom is interpreted in terms of the pπ-dπ-pπ conjugation.
Nuclear Quadrupole Effects in the Microwave Spectrum and Dipole Moment of Aniline
Authors: Hatta Aritada , Suzuki Masao , Kozima Kunio
Published: July 2006

The quadrupole hyperfine structure was resolved and analyzed for the vibrationally-ground state of the NH2 species. The quadrupole coupling constants are: χaa=2.34, χbb=1.86, and χcc=−4.20 MHz. The rotational constants obtained from the quadrupole corrected frequencies are as follows: A=5617.67, B=2593.88, and C=1777.04 MHz. The rotational constants of the ND2 species in the vibrationally-ground state were also determined. By the use of the moments of inertia of both species, the non-planarity of this molecule was ascertained. The dipole moments of the NH2 and the ND2 species were determined to be 1.15±0.02 D and 1.13±0.01 D respectively.
The Photoconductivity of Poly(N-vinylcarbazole). III. Photoconductivity in a Sandwich-type Cell.
Authors: Okamoto Kenichi , Kusabayashi Shigekazu , Mikawa Hiroshi
Published: July 2006

Photoconductivity in a sandwich-type cell of a PVCz film was investigated in a high vacuum and in the air. A large photociirrent was observed in the π–π* absorption region and a small photocurrent in the visible region. The former showed the following interesting points in its behavior. In low applied fields, no difference was found between the photoconductivity with positive-electrode illumination and that with negative-electrode illumination. In moderate or high fields, however, the photoconductivity with positive-electrode illumination was significantly different from that with negative-electrode illumination. The former showed a superlinear dependence on the applied field (consequently, iph+>>iph−) and a spectral response coinciding with the absorption spectrum. This photoconductive behavior was explained by assuming the mechanism of carrier generation, namely, the fieldassisted thermal dissociation of exciplexes and the detrapping of trapped carriers by singlet excitons. Carriers are supposed to migrate through the overlap of π-electrons of neighboring carbazyl rings in the same polymer chain.
Studies of the Preparation and Physical Properties of Multivalent Metal Condensed Phosphates. V. The Grinding of Various Aluminum Phosphates
Authors: Tsuhako Mitsutomo , Motooka Itaru , Kobayashi Masamitsu
Published: July 2006

Changes in the structures of various aluminum phosphates as a result of grinding were studied by a variety of physical methods—X-ray analysis, DTA, TGA, infrared absorption spectroscopy and electron microphotography, and their acidic properties were investigated in order to obtain information on the surface activity of the compounds. The X-ray diffraction patterns indicated that the A, B, and C types of Al4(P4O12)3 and AlPO4 (Berlinite) did not become completely amorphous even after grinding for 72 hr; this shows that the crystal structures of these compounds were relatively stable to grinding. Substance K was structurally more fragile than the other aluminum phosphates (Al4(P4O12)3, AlPO4), becoming completely amorphous on being ground for 72 hr. On DTA and TGA, the ground aluminum phosphates exhibited an endothermic peak, accompanied by a weight loss due to the loss of adsorbed water in the vicinity of 100°C. A further weight loss at higher temperatures was presumably due to dehydration caused by the condensation of P–OH. The amounts of acids on the ground aluminum phosphates were almost independent of the acid strength, which was around +1.5 (pKa). The amounts of acids of the A, B, and C types and of AlPO4 tended to increase slightly with the grinding time. The amount of acid of the K substance reached a maximum after 6 hrs grinding but decreased slowly when grinding was continued for longer than 15 hr.
Variational Calculation of Atoms and Molecules by a Modified Hassé Method Using Hulthén Functions. III. Long-range Interactions between Hydrogen Atom and Proton and between Two Hydrogen Atoms
Authors: Yamabe Tokio , Ishimaru Shingo , Fukui Kenichi
Published: July 2006

The variation method using the wave function of the modified Hassé form is applied to the problem of long-range interactions between hydrogen atom and proton and between two hydrogen atoms. The interaction energy is also related to the perturbation energy under the Unsöld approximation by the use of several pertinent approximations, and an “improved second-order Unsöld energy,” which will be higher than the exact second-order perturbation energy, is newly proposed. The numerical results show that the present trial wave function is quite effective; particularly, at R\gtrsim10 (a.u.), the dispersion energy between hydrogen atoms is better than that of Hirschfelder-Linnett, which might be the best variational result at a large nuclear separation. Furthermore, the importance of considering the degeneracy in treating the induction energy is numerically disclosed for an example of H–H+ interaction. The coefficients in the asymptotic form of the dispersion energy between two hydrogen atoms are briefly discussed, and, finally, a new method for the calculation of the second-order energy is suggested.
The Crystal Structure of Quinolinic Acid
Authors: Takusagawa Fusao , Hirotsu Ken , Shimada Akira
Published: July 2006

The crystal structure of quinolinic acid (2,3-pyridinedicarboxylic acid) has been determined by the method of X-ray diffraction. The crystal is monoclinic, with a space group of P21/c and with cell dimensions of a=7.421, b=12.729, c=7.850 Å, and β=116.96°. The crystal structure was solved by the inspection of a Patterson map. The final R value was 6.78% for 1224 observed reflections. The quinolinic acid molecule takes the form of a zwitter ion in the crystal. The pyridine ring in the molecules shows a significant deformation from the C2V symmetry of idealized geometry. The lengths of the two C–C bonds joining the carboxyl groups to the ring are longer than the normal value. There is an intramolecular hydrogen bond between the adjacent carboxyl groups. The bond lengths in the two C–O groups which participate in this intramolecular hydrogen bond are longer than those of the other two C–O groups. One of the two carbonyl oxygen atoms participates in a hydrogen bond, while the other is free from it. The molecules are arranged in layers closely parallel to the (0 1 0) plane. Each molecule on the same plane is hydrogen-bonded to form an endless chain along the a axis. These chains are packed by the van der Waals forces. The thermal diffuse scattering observed on Weissenberg photographs can be explained by this hydrogen-bond system.
Studies on Intermolecular Complex Formation. III. Crystal Structure of Thymine-N,N-Diethylmelamine Complex Monohydrate
Authors: Tamura Chihiro , Hata Tadashi , Sato Sadao
Published: July 2006

The crystal and molecular structure of the thymine-N,N-diethylmelamine complex monohydrate has been solved by means of the direct method. The crystals are monoclinic, with the space group of P21/c and with a=7.167, b=16.123, c=13.179 Å, and β=104.2°. The final R-factor for 1612 reflections is 0.087. These two components are hydrogen-bonded by a NH···N and two NH···O bonds with distances of 2.881, 2.821, and 3.006 Å. The complex formation ability for thymine and uracil has also been tested for some other organic compounds with amino and nitrogen heterocycles.
Optical and Magnetic Studies of CuSeO3·2H2O Based on the Refined Crystal Structure
Authors: Asai Takeshi , Kiriyama Ryôiti
Published: July 2006

Magnetic, IR and electronic spectral studies were made on CuSeO3·2H2O, its crystal structure being refined. The IR band at 927 cm−1 was found to be due to a rocking vibration of a water molecule. The H-bonding scheme was suggested. The electronic spectrum shows a maximum of the d-d transition bands at ca. 14000 cm−1. This was explained on the basis of a square pyramidal coordination of a Cu ion. Above 100 K the magnetic susceptibility obeys the Curie-Weiss law with θ=−92·6 K and μeff=2.00βB. At lower temperatures it shows a broad maximum at ca. 45 K, a sharp peak at 26.4 K corresponding to TN. The behaviour could be explained from the antiferromagnetic superexchange interactions of Cu cations through the σ-bonds of SeO32− anions. The small anisotropy and the number of cations intermediated by each anion give rise to the 1-dimensional character. A linear Heisenberg model and the molecular field model gave J⁄k values of −33 and −31 K, respectively. The latter model also gave the observed ratio of |θ|⁄TN.
Structural Studies of Tryptophan Metabolites by X-ray Diffraction Method. I. The Crystal and Molecular Structure of 5-Hydroxy-Dl-Tryptophan
Authors: Wakahara Akio , Kido Masaru , Fujiwara Takaji , Tomita Ken-ichi
Published: July 2006

5-Hydroxy-Dl-tryptophan was crystallized from a methanol solution in the monoclinic space group C2/c, with cell-dimensions of a=16.765, b=5.892, c=20.887 Å, and β=92.06°. The molecular structure and stereoconfiguration have been elucidated by the direct method for non-primitive space group. A Fourier map, calculated with the largest 198 normalized structure factors as Fourier coefficients, revealed the whole structure which was refined by the least-squares method. The molecule is a zwitterion as in the crystal structure of amino acids, each amino nitrogen atom having an extra proton. The indole ring plane forms a dihedral angle of 40° with that formed by an acid group. With respect to the conformation about the C(α)–C(β) bond, the orientation of C(β)–C(γ) bond is trans with respect to the C(α)–COO–. The molecules are arranged in double layers parallel to the ab-plane. The layer by polar groups is held together by a series of hydrogen bonds in a three-dimensional network, and by non-polar groups in the other layer, indole rings being stacked by van der Waals forces. The d-and l-forms of 5-hydroxytryptophan are hydrogen-bonded into two types of dimer related by the center of symmetry, one through N–H···O, and the other through O–H···O hydrogen bonding.
Crystal and Molecular Structure of ω-Amino Acids, ω-Aminosulfonic Acids and Their Derivatives. V. Crystal and Molecular Structure of γ-Guanidino Propane Sulfonic Acid
Authors: Kim Yang Bae , Wakahara Akio , Fujiwara Takaji , Tomita Ken-ichi
Published: July 2006

The crystal structure of γ-guanidino propane sulfonic acid was determined by the symbolic addition method with X-ray intensity data on a diffractometer and refined by the least-squares method to an R-value 0.069 for 1963 reflections. The crystals were monoclinic, space group P21/c, Z=8, with a=10.080, b=8.013, c=19.716 Å and β=98.17°. Two independent molecules in the asymmetric unit both have a zwitterionic form, (NH2)2+CNHCH2CH2CH2SO3−. There are two forms, trans zigzag and cis ones, which are linked by N(1)H···O hydrogen bonds. The molecules are held together in the crystal by a three-dimensional network of NH···O hydrogen bonds.
Reactions of Diphenylphosphinothioyl Isothiocyanate and Related Compounds with Some Nucleophiles and Carbodiimides
Authors: Ojima Iwao , Akiba Kin-ya , Inamoto Naoki
Published: July 2006

Diphenylphosphinothioyl isothiocyanate (1) reacted with alcohols, water and diphenylphosphinothioic acid to give the esters and anhydride of diphenylphosphinothioic acid by substitution reaction on the phosphorus atom, but reacted with amines by addition to the isothiocyanate group to afford diphenylphosphinothioylthioureas or their ammonium salts. Diphenylphosphine and p-toluenethiol, however, did not react with 1. On the contrary, diphenylphosphinothioyl isocyanate underwent only addition reaction with water, amine and thiol. Isothiocyanate (1) and p-toluenesulfonyl isothiocyanate were found to undergo 1,2-cycloaddition reaction with carbodiimides across the C=S bond to produce 1,3-thiazetidine derivatives.
Synthesis of Carbocydic Adenosine Analogs: 9-(2′,3′,4′,5′-Tetrahydroxycyclopentyl)adenines
Authors: Suami Tetsuo , Nishiyama Shigeru , Tadano Kinichi , Lichtenthaler Frieder W
Published: July 2006

The synthesis of five 9-(2′,3′,4′,5′-tetrahydroxycyclopentyl)adenines with 1,2,4/3,5- (2a), 1,2,3/4,5- (2b), 1,4,5/2,3- (2c), 1,4/2,3,5- (2e) and all-cis configuration (2d) are described, by animation of 4-amino-5-nitro-6-chloropyrimidine with the respective 5-aminocyclopentanetetrols (3a–e), followed by reduction of the nitro group and cyclization with formamide.

Prelimimnary anyifungal properties are reported.
Some Doping Effects on the Semiconducting Properties of Gd2CuO4
Authors: Kenjo Tadao , Yajima Seishi
Published: July 2006

Some doping effects on the semiconducting properties of the Gd2CuO4 compound were investigated. The ZrO2 or ThO2 (0.5 mol%) lowered the resistivity of the Gd2CuO4 at room temperature by a factor of 104. The thermoelectric powers of the same samples were negative. These were explained as being due to the Cu+ ions formed by the dopants. The CaO dopant lowered the resistivity by a factor of ten and converted the sign of the thermoelectric power from negative to positive. The resistivity of the BaO-doped samples increased with an increase in the dopant concentration up to 0.5 mol%, and decreased with an increase in the dopant concentration in the concentration region lower than that. This suggested that the dopant of BaO was less effective on the resistivity-lowering than was the CaO. The samples doped with the ZrO2 and CaO simultaneously gave a trend similar to those doped with the BaO in the concentration dependence of the resistivity. Silver oxide and indium oxide were also employed as dopants, but no doping effects were observed on either resistivity or the lattice parameters.
Studies of the DNA–Acridine Complexes. I. Fluorescence Depolarization
Authors: Kubota Yukio
Published: July 2006

The motion of the DNA–acridine complexes in solution was studied by the fluorescence depolarization method. Five derivatives of 3,6-diaminoacridine were used in order to investigate the effect of amino substituion on the depolarization results. A linear relation between the reciprocal polarization (1/P) and T/η was obtained by varying the temperature of a native DNA–acridine solution. The limiting polarization (P0) and the mean rotational relaxation time (ρh) of the complex were evaluated from these data. The ρh value of the complex (30–50 nsec) was much larger than the value of free acridine in water, but it was much too small to correspond to the rotation of the whole DNA molecule. Further, it was found that the values of P0 and ρh for 3,6-bis(diethylamino)acridine are much smaller than those for other acridines. This may result from some steric hindrance of the binding by bulky diethylamino groups.
Mechanism of Hydrogenolysis. III. Thermal Hydrogen Exchange and Demethylation of Toluene-2-d1, -3-d1, and -4-d1
Authors: Sato Yoshiki , Amano Akira
Published: July 2006

Rates of gas phase thermal hydrogen exchange and hydrogenolytic demethylation of toluene-2-d1, -3-d1, and -4-d1 are evaluated using flow apparatus at temperatures 675–750 °C in the presence of a large excess molecular hydrogen. Both the exchange and the demethylation obey three-halves order rate law indicating the chain mechanism carried by hydrogen atom, the former being found slightly faster than the latter. Rate parameters of the two reactions taking place concurrently are then correlated with the extended Hückel superdelocalizability values appropriate to methylcyclohexadienyl transient formation. Overall applicability of the dynamic index as a measure of reactivity of deuteriotoluenes toward hydrogen atom attack is taken as an additional support for the generally accepted chain mechanism whose rate-determining step consists of electroneutral hydrogen atom addition to aromatic nucleus.
Simulation Analysis of the Acid–catalyzed Hydrolysis of Carboxylatopentammineruthenium(III) Complexes
Authors: Ohkubo Katsutoshi , Sakamoto Hiroyuki , Kitagawa Futoshi , Ohyoshi Akira
Published: July 2006

The mechanism of the acid-catalyzed hydrolysis of (NH3)5RuO2CR2+ (R=H, CH3, C2H5, (CH3)2CH, CH2OH, and/or CH2NH2) has been established by the trapezoidal simulation analyses with a computer. The proposed reaction sequences of SN1 combined with SN2 mechanisms involving a quasi-stable intermediate (NH3)5Ru3+ have proved to be plausible, and the kinetic parameters (rate constants, ΔH\eweq, ΔS\eweq, etc.) have been given for all of the elementary reactions. The aquation rate has been determined by the solvent-assisted, heterolytic dissociation of (NH3)5RuO2CR2+ and follows this order: formato>acetato>propionato>isobutyrato>glycolato>glycinato.
Charge Transfer in Acetonitrile–Halogen Complexes
Authors: Negita Hisao , Shibata Kaoru , Furukawa Yoshihiro , Yamada Koji
Published: July 2006

The charge transfer in acetonitrile-halogen complexes was examined by means of the nuclear quadrupole resonances resulting from the relevant nuclei. 14N NQR parameters (|e2Qq|=3.6000 MHz and η=0.0183) and 35Cl NQR parameters (|e2Qq|=107.44 and 108.50 MHz) were obtained for the acetonitrile-chlorine complex, whereas 14N NQR parameters (|e2Qq|=3.5439 MHz and η=0.0043) and a 81Br NQR parameter (|e2Qq|=640.52 MHz) were obtained for the acetonitrile-bromine complex. From these parameters, the charged states of the nitrogen, chlorine, and bromine atoms in these charge-transfer complexes were calculated by means of the Townes and Dailey theory. In the case of the acetonitrile-bromine complex, the charge loss at the nitrogen atom was not equal to the gain at the bromine atom, as long as the charge was assumed to be transferred only to the p-orbital of the latter. This discrepancy was explained by assuming some d-hybridization at the bromine atom. The charged states of the nitrogen atoms in these complexes were qualitatively in good agreement with the electron affinities of the chlorine and bromine molecules. Moreover, the temperature dependences of the 14N and 81Br nuclear quadrupole coupling constants in the acetonitrile-bromine complex were investigated in the range from −196 to −60 °C.
Counterion Effect on the Titration Behavior of Poly(maleic acid)
Authors: Muto Nobuhiko , Komatsu Tsuyoshi , Nakagawa Tsurutaro
Published: July 2006

The potentiometric titration of poly(maleic acid) (PMaA) in aqueous solutions containing alkali metal salts and a tetramethylammonium salt was carried out at 25 °C, and the effect of the counterions on the titration behavior of PMaA was examined in detail. The acidity of the primary carboxylic groups of PMaA increases in the order of (CH3)4N+<Li+<Na+<K+, whereas that of the secondary carboxylic groups increases with the decrease in the crystallographical radius of the counterions, in agreement with the results for ordinary polycarboxylic acids. The order of K+>Na+>Li+ for the binding strength to the primary carboxylate groups of PMaA is interpreted in terms of the radius of the hydrated cations; it can be attributed to the stable ring structure of the monoanion of the maleic acid residue, resulting from the hydrogen bonding between two adjacent carboxylate groups.
Solvent Effect in Electron Spin Resonance Spectra and Electrochemical Reaction of Substituted Nitrobenzene Anion Radicals
Authors: Fujinaga Taitiro , Deguchi Yasuo , Umemoto Kisaburo
Published: July 2006

In order to examine the effect of solvents on the hyperfine splittings of anion radical the electron spin resonance spectra of substituted nitrobenzene anion radicals were studied. The effect of hydroxylic solvent is enhanced when the nitro group is forced out of the plane of the benzene ring due to the steric influence of the bulky functional group at the ortho position. The effect is reduced when the nitro group forms intramolecular hydrogen bond with the hydroxyl group at the ortho position. A model for the solvent effect considering the hindered rotation of the nitro group in the radical molecule caused by the formation of intermolecular hydrogen bond with solvent is found to be reasonable from a molecular orbital calculation, taking account of changes in molecular orbital parameters resulting from hydroxylic solvation. The shifts in polarographic half wave potentials with the solvent system as well as the dehalogenation reaction in the course of electrochemical reduction of halonitrobenzenes is interpreted by means of the model.
Studies on Fragment Ion Distribution and Reactions with the Use of a Charge Spectrometer. IV. Dependence of Cross Sections of Some Ion–Molecule Reactions on the Kinetic Energy of Ions
Authors: Nagatani Toshio , Yoshihara Kenji , Shiokawa Takanobu
Published: July 2006

Gross sections of methylamine and methanol for ion-molecule reactions with various rare gases have been studied by means of a charge spectrometer used as a double mass spectrometer. The results differed from those predicted by the Gioumousis-Stevenson theory. The difference was most pronounced for helium ion, the lightest ion.
Ultrasonic and Thermodynamic Studies on the Aqueous Solutions of Tetramethylurea
Authors: Sasaki Katsutaka , Arakawa Kiyoshi
Published: July 2006

Ultrasonic absorption and sound velocity were measured for aqueous solutions of tetramethylurea at temperatures 10–30 °C. Excess compressibility and partial molar volume were obtained. The curves for the concentration dependence of density, viscosity, and absorption show a maximum at about 60 vol% (20 mol%). The excess compressibility curve shows a minimum at the same concentration. It is concluded that a molecular complex of the molar ratio 4: 1 (water: tetramethylurea) linked with hydrogen-bonds is formed at 20mol%. In a dilute solution (below 4mol%), the magnitude of ultrasonic absorption of tetramethylurea solutions is equal to that of 1,3-dimethylurea solutions, but is less than that of 1,3-diethylurea solutions. The tetramethylurea–water interaction is of a similar nature to that between 1,3-dimethylurea and water in a dilute solution.
Crystal Structure and Absolute Configuration of (−)-2,2′-Bisbromomethyl-1,1′-binaphthyl
Authors: Harata Kazuaki , Tanaka Jiro
Published: July 2006

Crystals of (−)-2,2′-bisbromomethyl-l′-binaphthyl have been subjected to crystal structure analysis in order to determine the absolute configuration of optically active 1,1′-binaphthyl derivatives. The crystals are orthorhombic, space group P212121 with Z=4 and the lattice constants are; a=10.360, b=13.052, c=13.178 Å. The structure was solved by the heavy atom method and the final R index was 0.064. The absolute configuration was determined as (S)-configuration by utilizing the anomalous dispersion effect of bromine atom.
Infrared Absorption Intensities of Torsion–Rotation Transitions of Molecules with Symmetric Internal Rotor
Authors: Sugeta Hiromu , Miyazawa Tatsuo
Published: July 2006

The infrared absorption intensities of torsion-rotation transitions were theoretically derived on the basis of torsion-rotation interactions of molecules with symmetric internal rotor. The theoretical intensities depend upon molecular structure parameters and molecular dipole moment. Implications of the present theory are discussed on absolute intensities, orientations of dipole transition moment, band types (A, B, or C), and deuteration effects on absorption intensities of methyl torsional transitions. For propylene oxide and propylene sulfide, the far infrared spectra of the gaseous state were measured, and the experimental absorption intensities of methyl torsional vibrations were compared with theoretical intensities.
Distribution of Alkali Metal Picrates between Water and Methyl Isobutyl Ketone
Authors: Iwachido Tadashi
Published: July 2006

As regards the distribution of alkali metal picrates between water and methyl isobutyl ketone, distribution ratios of alkali metals and acid species were determined in the pH range 1.5–8.5. The extraction curves are almost the same for each alkali metal. Association constants of the picrates and the dissociation constant of picric acid in the organic phase were determined conductometrically. The association constants of picrates in the aqueous phase were determined with distribution coefficients by means of a solvent extraction method. The results obtained show that the picrates exist mainly in a dissociated form in both phases, whereas picric acid exists in a weakly dissociated form in the organic phase. The extractability of picrates is discussed on the basis of the extraction parameter proposed and compared with that of the nitrobenzene system.
ESR of Copper(II) Complexes in Magnetically Non-dilute Crystals. I. Single Crystals of Bis(l-alaninato)copper(II)
Authors: Yokoi Hiroshi , Ohsawa Shigeru
Published: July 2006

Single-crystal ESR studies have been carried out on bis(l-alaninato)copper(II). Only one symmetric absorption peak has been obtained in any direction of the magnetic field, regardless of the fact that there are two molecules per unit cell. The principal values and the directions of the principal axes of the g tensor have been determined, and a correlation between those components of the g tensor and the crystal structure has been confirmed on the basis of the effect of the spin-exchange interaction between the dissimilar copper(II) ions. The absorption linewidths have been examined in order to estimate the spin-exchange energy.
Kinetics and Mechanisms of the Reactions of Ce(IV) and Co(III) with Variamine Blue, [N-(p-Methoxyphenyl)phenylenediamine], in Aqueous Perchlorate Media
Authors: Imamura Taira , Fujimoto Masatoshi
Published: July 2006

The kinetics of the non-complementary reactions of Ce(IV) and Co(III) with Variamine Blue perchlorate were studied under nitrogen atmosphere in aqueous perchlorate media of ionic strength μ=2.0 M. The iminoquinone form of Variamine Blue was spectrophotometrically followed at 550 nm by stopped-flow technique. The rate constants of the stepwise reaction, Mn++(V.B.)\oversetkα\undersetkγ\ightleftharpoonsM(n−1)++(V.B.)sox,Mn++(V.B.)sox\xrightarrowkβM(n−1)++(V.B.)ox+2H+ were evaluated at 25°C to be kα=1.7×105 and kβ=2.4×105 M−1 sec−1 for Ce4+ and kα=1.35×104 and kβ=1.53×104 M−1sec−1 at [H]=1.0 M for Co3+. The rates of Ce4+ were not affected by [H]. The [H]-dependece of kα and kβ for Co3+ gives the mechanism Coaq3++B\oversetk1\ightleftharpoons product, CoOHaq2++B\oversetk2\ightleftharpoons product, Coaq3+\oversetKh\ightleftharpoonsCoOHaq2++H+, with K2\simeq107 M−1sec−1, suggesting an outer-sohere mechanism for the electron transfer with CoOH2+.
Photochemical Reactions of Uranyl Ions with Organic Compounds. V. Effects of Temperature and Solvent on the Photooxidation of Alcohols
Authors: Sakuraba Shukichi , Mimura Soichi , Matsushima Ryoka
Published: July 2006

A comparative study of the photokinetic behaviors of aliphatic alcohols and related substrates was made for the photooxidation with uranyl ions. Ethylene glycol, glucose, sucrose and some other substrates showed abnormal results compared to a series of simple aliphatic alcohols: the photoredox quantum yields φ for the former substrates decreased with substrate concentration (at their higher concentrations) and temperature rise, in contrast to simple aliphatic alcohols. In aqueous acetone solution φ increased with the increase in acetone content, the reaction constant ρ* being more negative than in aqueous solution. In 40% aqueous acetone solution the φ values for simple aliphatic alcohols varied in a complicated way with temperature. The abnormal results were interpreted in terms of the relative importance of physical quenching competing with the primary chemical process.
Kinetics of the Oxidation of Ascorbic Acid by the Copper (II) Ion in an Acetate Buffer Solution
Authors: Hayakawa Katumitu , Minami Shoko , Nakamura Sumio
Published: July 2006

The kinetics of the oxidation of ascorbic acid by the copper(II) ion has been studied spectrophotometrically by a stopped-flow technique. At pH 4–6, the initial rate of the decrease in the monohydroascorbate anion is of the second-order with respect to the total concentration of the copper(II) ion and of the first-order with respect to the concentrations of the monovalent and divalent ions of ascorbic acid:

-(d[HA^-]/dt)_t=0=k_1[Cu(II)]_T^2[HA^-]+k_2[Cu(II)]_T^2[A^2-]

where HA− and A2− are the monovalent and divalent ions of ascorbic acid respectively. k1, k2, and the activation parameters are obtained as follows: k1=3.1×104, k2=6.1×1010 M−2 s−1, ΔH\eweq=17 kcal/mol, ΔS\eweq=8.3 cal/deg mol, and ΔG\eweq=15 kcal/mol. The EPR signal from the ascorbate radical is not observed in the kinetic run by either a flow technique or a quenching technique. Some discussions of the mechanism of the reaction are given.
H+ Ion Equilibria in Solutions of Copolypeptides of l-Lysine and l-Aspartic Acid and of l-Lysine and l-Glutamic Acid
Authors: Atreyi M , Gupta R C
Published: July 2006

pH and conductometric titration curves of copolypeptides containing l-lysine and either l-glutamic acid or l-aspartic acid residues have provided necessary evidence to believe that in the copolypeptides the zwitterion formation is complete at the isoionic point. The amounts of acid/alkali used up at the final inflexion/break in the titration curves agreed with the analytically determined quantity of basic/acid groups in the copolypeptides. Besides, the titration curves showed additional inflexions/breaks which distinguished between the various kinds of acid/basic groups present.
The Reaction of Nitriles under High Pressure. II. The Catalytic Effects of Amines and Water on the Formation of Trisubstituted 1,3,5-Triazines from Nitriles
Authors: Yasumoto Masahiko , Yanagiya Koshin , Kurabayashi Masahiro
Published: July 2006

When a mixture of benzonitrile and methanol is kept under a high pressure of a few thousand atoms at an elevated temperature, methyl benziminoether is produced and trimerized to triphenyl-1,3,5-triazine. In the present study it was confirmed that the addition of ammonium salts or some nucleophiles with an active hydrogen atom such as water, amines, and ammonia at several per cents in the molar fraction increases the rate of the formation of this triazine by several times. It was found that the nucleophilic benzamidines produced by the reaction of benziminoether with amines attacked the second molecule of the iminoether and successively took the third iminoether molecule to form a triazine ring. The addition of water to the nitrile-methanol mixture produced amidine, methyl ester, amide, and amidinium carboxylate, of which the carboxylate exhibited the highest promotive effect. Some benzamidines were obtained in fairly good yields from amines and benzonitrile under similar high-pressure conditions. It is thought that this could be useful for synthesizing amidines.
The Reaction of Nitriles under High Pressure. IV. The Replacement of the Substituents of Trialkyl-1,3,5-triazines
Authors: Yanagiya Koshin , Yasumoto Masahiko , Kurabayashi Masahiro
Published: July 2006

It was found that, when some symmetrically 2,4,6-tri-substituted 1,3,5-triazines are kept with an iminoether or an amidine under high pressures and at elevated temperatures, unsymmetrically 2,4,6-tri-substituted 1,3,5-triazines are produced by way of the replacement of one or two (Remark: Graphics omitted.) groups of the triazines with the (Remark: Graphics omitted.) group of the iminoether or that of the amidine. Several mixtures of nitriles and methanol can be used for this replacement reaction in place of iminoethers or amidines at 4000–8000 atm and 100–150 °C. In these mixtures, equilibrium amounts of methyl iminoethers are rapidly formed. Increases in the size of the substituents of the original triazine and in their electron-releasing power inhibit this replacement reaction. Nitriles with an electron-releasing moiety give tri-substituted triazines replaced selectively by one of the original substituents.
Linear Conjugated Systems Bearing Aromatic Terminal Groups. XII. Syntheses and Electronic Spectra of α,ω-Di-2-pyrenyl-and α,ω-Di-2-fluorenylpolyenes
Authors: Takeuchi Yasuhira , Yasuhara Akio , Akiyama Shuzo , Nakagawa Masazumi
Published: July 2006

The syntheses of α,ω-di-2-pyrenyl- and α,ω-di-2-fluorenylpolyenes In and In′ (n=1–6) by means of the Wittig reaction are described. Aldehydes II, II′, propenals IV, IV′, pentadienals V, V′ bearing 2-pyrenyl or 2-fluorenyl terminal group and muconaldehyde VI were used as carbonyl components. Phosphoranes III, III′, VII, VII′, VIII and VIII′ were prepared from methyl-, propenyl-, and pentadienyltriphenylphosphonium bromides substituted with 2-pyrenyl or 2-fluorenyl group by the reaction with phenyllithium. In and In′ were obtained by the reaction of carbonyl components with phosphoranes by proper combination. It was found that the bathochromic shift of the longest-wavelength peaks of In and In′ can be expressed by the following empirical equations:

& I_n:λ=44.6n^0.7+314 (nm in tetrahydrofuran)

& I_n’:λ=29.5n^0.8+353 (nm in tetrahyhrofuran)
Linear Conjugated Systems Bearing Aromatic Terminal Groups. XIII. Syntheses of α-(p-Methoxypheny)-ω-(p-nitrophenyl)polyenes
Authors: Takeuchi Yasuhira , Akiyama Shuzo , Nakagawa Masazumi
Published: July 2006

α-p-Methoxyphenyl-ω-p-nitrophenylpolyenes (IIIn, n=1–5) were prepared by the Wittig reaction of p-methoxyphenylpolyenals (I, n=1–5) with phosphorane derived from p-nitrobenzyltriphenylphosphonium bromide (II). The electronic spectra of IIIn showed broad and structureless absorption curves. However, the trend of bathochromic shift of long wavelength absorption maxima with increasing length of polyene chain suggests that no alternation in the type of light-absorption of polyene chromophore is caused by the introduction of electron donating and withdrawing substituents in the terminal phenyl groups.
A New Hypothesis Regarding the Surface Acidity of Binary Metal Oxides
Authors: Tanabe Kozo , Sumiyoshi Takashi , Shibata Katsue , Kiyoura Tadamitsu , Kitagawa Jun
Published: July 2006

We have proposed a new hypothesis that the acid sites on binary metal oxides are formed by an excess of a negative or positive charge in the mixed oxides and that whether the charge is excess or not, and whether it is positive or negative, are determined by the coordination numbers and valences of the positive and negative elements in the model structures pictured according to two postulates. The validity of the hypothesis is, in fact, 90% for the 31 kinds of binary oxides tested, much higher than the validity (48%) of Thomas’ hypothesis. The hypothesis explains well the mechanism of the acidity generation of binary oxides and predicts whether the acid sites will be of the Brönsted or the Lewis type.
The Raman Spectra and Molecular Conformations of Surfactants in Aqueous Solution and Crystalline States
Authors: Okabayashi Hirofumi , Okuyama Masataka , Kitagawa Teizo , Miyazawa Tatsuo
Published: July 2006

The Raman spectra were measured for sodium alkyl sulfates and potassium aliphatic carboxylates in the solid state and aqueous solutions. Vibrational assignments of Raman lines were made, and characteristic Raman lines of the alkyl sulfate ion were identified. The ethyl sulfate ion in the aqueous solution was found to exist predominantly as the trans form about the CH2–O bond. For higher alkyl sulfate ions in aqueous solutions, Raman lines due to rotational isomers with gauche CH2–CH2 bonds were observed. Longitudinal accordion frequencies of the solid state and aqueous solutions were compared in order to discuss the conformations of hydrocarbon chains in solution.
Electrical Properties of Ferric Oxyhydroxides
Authors: Kaneko Katsumi , Inouye Katsuya
Published: July 2006

The electrical conductivity of α-FeOOH, β-FeOOH, and γ-FeOOH was measured in dry air at room temperature in the frequency range of dc to 10 MHz under various pressures of 9–150 kg/cm2. The logarithm of conductivity, log σ, shows a linear relationship with the ratio of true density to apparent density, d0/d′, of the samples compressed at different pressures. σ1 at 7 MHz, determined by extrapolating the logσ vs.  d0/d′ plots to unity of d0/d′, is proportional to the number of the nearest iron atoms with identical spin. The conductivity increases with increasing frequency f. The ac conductivity σac which equals σ minus σdc, where σdc is the dc conductivity, is proportional to fs (0.6<s<0.8) in the lower frequencies than 1 MHz. This behavior is presumed to be due to the hopping of a d-electron in the t2g-orbital of Fe2+ to the t2g-orbital of adjacent Fe3+, through a slight overlapping of t2g-orbitals of Fe2+ and Fe3+.
Brillouin Scattering and Elastic Constants of Tetragonal Pentaerythritol
Authors: Matsuura Hiroatsu , Miyazawa Tatsuo
Published: July 2006

The Brillouin scattering from tetragonal pentaerythritol crystals was measured by using a helium–neon laser and a pressure-scanned Fabry-Perot interferometer. The Brillouin components from the longitudinal acoustic mode and the transverse acoustic mode polarized parallel to the scattering plane were observed for various crystal directions with the scattering vector in the (001) and (010) planes. From the observed Brillouin shifts, the frequencies and velocities of sound waves with the wavelength of 290 nm were obtained, and the elastic constants were determined, in units of 1011 dyn/cm2, as C11=3.94±0.01, C13=0.76±0.03, C16=0.005±0.05, C33=1.33±0.02, C44=0.44±0.03, and 2C66+C12=5.13±0.03. The present hypersonic values of the elastic constants were compared with previous values by the ultrasonic technique.
Synergism in the Liquid-Liquid Extraction and the Extractio Chromatography of Manganese(II), Cobalt(II), and Zinc(II) in the Thenoyltrifluoroacetone–Trioctylphosphine Oxide–Cyclohexane Extraction System
Authors: Honjo Takaharu , Horiuchi Masanobu , Kiba Toshiyasu
Published: July 2006

The synergism appearing in the liquid-liquid extraction and the extraction chromatography of trace amounts of manganese(II), cobalt(II), and zinc(II) has been investigated with TTA (thenoyltrifluoroacetone) in various solvents with or without TOPO (tri-n-octylphosphine oxide). For example, the pH1⁄2 of the extraction of Co(TTA)2 differed with the solvent used; it was, for example, 4.1 for nitrobenzene, 4.6 for cyclohexane, and 5.2 for benzene, when examined with 0.1 M TTA. When 0.01 M TOPO was present under the same conditions, the above values became 3.3, 2.4, and 3.1 respectively. The synergism was thus found to become more effective as a less polar solvent was used. The extraction constants of the three metals with only 0.1 M TTA–cyclohexane increases in the order of Mn(II)–Zn(II)–Co(II); however, when 0.001 or 0.01 M TOPO was present, all the extraction curves of the three metals became identical, even in the acidic region of pH 1–4. The overall stability constants of the adducts, M(TTA)2–(TOPO)n, increased in the order of Zn(II)–Co(II)–Mn(II), unlike the case of M(TTA)2. The adducts were found to have two TOPO for Mn(II) and Co(II), but only one for Zn(II). The extraction equilibria were found to be attained within two minutes. Unlike as in the batch extraction, the columnextraction chromatography gave a dissimilar order of the extractability of three metals (Zn(II)–Mn(II)–Co(II)) when 0.1 M TTA–cyclohexane was the stationary phase on Kel–F in the presence of TOPO. The mutual separation could not be achieved among these metals in the presence of TOPO, and the synergism was found to be rather unfavorable for the separation of metals. The relation between the batch extraction and the extraction chromatography was also discussed briefly on the basis of the distribution data obtained.
Studies on Amino-hexoses. XVIII. A Simplified Method of Preparing 2-Amino-3-O-(d-1′-carboxyethyl)-2-deoxy-d-glucose 6-(Dihydrogen Phosphate) (Muramic Acid 6-Phosphate)
Authors: Hase Sumihiro , Matsushima Yoshio
Published: July 2006

Muramic acid 6-phosphate was prepared from benzyl 2-acetamido-2-deoxy-3-O-[d-1′(methoxycarbonyl)-ethyl]-α-d-glucopyranoside via two reaction stages: diphenylphosphorylation under restricted conditions, followed by hydrolysis. When the reaction mixture was chromatographed on a Dowex 1×8 (formate form) column, the product was obtained as fine needles. Among the periodate oxidation products of the compound, glycolaldehyde phosphate was detected, while formaldehyde was not. Equimolar amounts of muramic acid and inorganic phosphate were produced by an alkaline phosphatase. The physical data are consistent with those of authentic muramic acid 6-phosphate.
The Formation of Ethers from Borneol and Isoborneol in the Presence of Boron Trifluoride Etherate
Authors: Nagai Kimiko , Nakayama Mitsuru , Matsuo Akihiko , Eguchi Shizuko , Hayashi Shûichi
Published: July 2006

dl-Borneol and dl-isoborneol, when separately submitted to the action of boron trifluoride etherate at room temperature, gave different ethers; the one from borneol was characterized as bornyl isobornyl ether, and the other from isoborneol, as diisobornyl ether. The ethers were also obtained from borneol and isoborneol in the reaction with zinc chloride. When d-borneol was used, an optically-active bornyl isobornyl ether was obtained.
Synthetic Studies of Carbohydrate Derivatives with Photochemical Reactions. X. An Unusual Photo-induced Addition of Lactonitrile to Some Enoses
Authors: Matsuura Kazuo , Senna Kazuo , Araki Younosuke , Ishido Yoshiharu
Published: July 2006

The photochemical addition of lactonitrile to 3,4,6-tri-O-acetyl-d-glucal, 2,3,4,6-tetra-O-acetyl-2-hydroxy-d-glucal, methyl 4,6-di-O-acetyl-2,3-dideoxy-α-d-erythro-hex-2-enopyranoside, and methyl 5-deoxy-2,3-O-isorpopylidene-β-d-erythro-pent-4-enofuranoside afforded 1′-cyanoethyl 4,6-di-O-acetyl-2,3-dideoxy-α-(6a) and -β-d-erythro-hex-2-enopyranoside(6b), 1′-cyanoethyl 2,4,6-tri-O-acetyl-3-deoxy-α- and -β-d-erythro-hex-2-enopyranoside, 6a and 6b, and 1′-cyanoethyl [methyl (4R)-5-deoxy-2,3-O-isopropylidene-β-d-erythro-pentofuranosid]-4-uloside respectively, all in good yields. These facts can be explained by assuming the catalytic effect of a certain acidic species which might extricated from lactonitrile during the irradiation.
Catalytic Hydrogenation of Cyclic Olefins on Nickel Catalysts
Authors: Kajitani Masatsugu , Sasaki Yoshiaki , Okada Junko , Ohmura Kazuo , Sugimori Akira , Urushibara Yoshiyuki
Published: July 2006

The catalytic hydrogenation of cyclic olefins was investigated over various nickel catalysts. The hydrogenation of cyclohexene was promoted by basic reaction conditions and depressed by acidic ones, the hydrogenation of cyclooctene being only slightly influenced by the acidity. The results of competitive hydrogenation indicate that cyclooctene is adsorbed more strongly on nickel catalysts than cyclohexene. The external olefinic bond is preferentially hydrogenated to the internal olefinic bond.
Oxytocin Analogues Containing No Disulfide Bond. III. The Synthesis of Three Analogues of 1,6-Aminosuberic Acid-Oxytocin
Authors: Yamanaka Tsutomu , Sakakibara Shumpei
Published: July 2006

[Asu1,6]-oxytocin, an analogue of deamino-oxytocin in which the disulfide bond is replaced by an ethylene linkage, is completely resistant to deterioration during storage under concentrated conditions. In the present study, three new analogues of this material, [Phe3, Asu1,6]-oxytocin, [Val4, Asu1,6]-oxytocin, and [Gly7, Asu1,6] -oxytocin, were synthesized to find out a hormonal compound possessing a specifically higher uterotonic activity. Among them, the [Gly7]-analogue was found to be the most promising compound; it showed a relatively higher uterotonic activity (245 IU/mg) in the rat, with a faint antidiuretic activity (0.02 IU/mg) and a weak depressor activity.
Substituent Effects in the Benzofuran System. I. Proton and Carbon-13 Chemical Shifts
Authors: Okuyama Tadashi , Fueno Takayuki
Published: July 2006

PMR and CMR spectra of benzofuran and its derivatives (2-CH3, 3-CH3, 5-CH3, 6-CH3, 5-CH3O, 6-CH3O, and 5-Cl) have been measured. The chemical shifts of 2-H and 2-C of 5- and 6-substituted derivatives obeyed a modified Hammett equation, δ=ρ1σ1+ρ2σ2+δ0. Electronic effects were found to be transmitted mainly through the bond 8–3. It was concluded that the ground-state electronic structure is similar to that of styrene rather than phenyl vinyl ether.
Molecular Structure of Tungsten Oxide Tetrachloride by Gas Electron Diffraction
Authors: Iijima Kinya , Shibata Shuzo
Published: July 2006

The molecular structure of tungsten oxide tetrachloride was determined by the sector-microphotometer method of gas electron diffraction. The molecule was found to have a square-pyramidal structure, and the following molecular parameters were obtained by a least-squares method; rg(W–Cl)=2.281±0.003 Å, rg(W–O)=1.686±0.011 Å, and rg(Cl···Cl(s))=3.151±0.015 Å. The OWCl angle, 102.4±1.3°, is much larger than the corresponding angles found in other square-pyramidal molecules such as XeOF4 and IF5.
Isoelectric Point of Manganese Oxide
Authors: Morimoto Tetsuo , Kittaka Shigeharu
Published: July 2006

The isoelectric point (IEP) of manganese oxide is measured on samples prepared by heating β-MnO2 and amorphous manganese oxide, MnO1.75, at temperatures from 200 to 1400°C. The IEP values thus obtained are characteristic of each stage of the oxidation of manganese oxide; that is, <5.1 for MnO2, 7.6–9.0 for α-Mn2O3, and 3.3–5.2 for Mn3O4. These values can be explained by the electrostatic interaction theory introduced by Parks, in which the CFSE correction is eliminated. It is also found that manganese ions with specific valencies are responsible for the electrification of the surfaces of manganese oxide.