bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies on 3,5-pyrazolidinediones. IV. Addition of 4-Arylazo-3,5-pyrazolidinediones to Ethyl Acrylate
Authors: Elnagdi Mohamed Helmi , Ohta Masaki
Published: July 2006

4-Arylazo-3,5-pyrazolidinediones (I) react with ethyl acrylate to yield the corresponding 1-β-ethoxycarbonylethyl derivatives (III), which were readily hydrolyzed into the acids IV. Compounds III and IV were found to react with acrylonitrile to yield the corresponding 1-substituted 2-β-cyanoethyl derivatives V and VI respectively. Whereas III and IV were recovered unchanged upon treatment with aniline or piperidine, the arylazomalonic acid dihydrazide (IX) were formed upon treatment of III or IV with hydrazine hydrate. 2-p-Chlorophenylazotetrahydropyrazolo[1,2-a]pyrazole-1,3,7-trione (XI) has been prepared by the action of phosphorus oxychloride on IVb. 3-Amino-4-phenylazo-2-pyrazolin-5-one (II) react with ethyl acrylate to yield the pyrazolo[1,5-a]pyrimidine derivative XII.
Equilibrium Composition of 1-Butanol–Water–Alkali Hydroxide System and Distribution of the Base
Authors: Yui Norio , Kurokawa Y\={o}ichi , Sakuraba Isozi
Published: July 2006

Equilibrium compositions of 1-butanol–water–MOH systems were studied at 25 °C, where MOH represents LiOH, NaOH, and KOH. Water and 1-butanol were determined by means of gas chromatography and the bases by titration. Apparent distribution ratio Kobs (molality of MOH in the aqueous phase/molality of MOH in the 1-butanol phase) was dependent on the concentration of base. A considerable amount of water was transferred from 1-butanol to the aqueous phase giving rise to an increase of base concentration. This suggests that the variation of Kobs depends principally on the variation of solvent composition. Kobs was expressed semi-empirically, considering the activity coefficients calculated by Miller’s equation and also the change in the standard free energy resulting from the variation in solvent composition. Decrease of 1-butanol in the aqueous phase with the base concentration obeyed the salting-out equation. The calculated salting-out coefficients were: LiOH 0.176, NaOH 0.192, and KOH 0.184. These values are correlated to Gurney’s unitary entropy. The results were compared with those previously obtained for alkali halides.
An Interstitial-Electron Model for the Structure of Metals and Alloys. VI. Interpretation of Superconductivity
Authors: Johnson Oliver
Published: July 2006

A physical interpretation of the superconducting state based on the interstitial-electron model for metals is given within the framework of the BCS theory. The following conditions for itinerant electrons (\bare) and metal ion cores (Mn+) are postulated as necessary for superconductivity: (1) There must be a matching of \bare energies (velocity) and binding strength of Mn+ so \bare initiation of a lattice vibration is possible. (2) Movement of \bare and Mn+ must be synchronized so there is enhancement of \bare-phonon coupling. (3) There must be \bare of one spin available to enter such \bare-phonon “chains”. The model leads to \bare of opposite spin in phonon chains 500–5000 Å apart. It gives physical interpretations of the thermodynamic properties of superconductors and clearly shows that type of lattice influences superconductivity. It shows the basis for the new correlation observed between superconductivity and a positive Hall Coefficient. Since the model can incorporate the presence of anions as well as \bare, it provides a related explanation for superconductivity in non-metals.
The Photoconductivity of Poly(N-vinylcarbazole). I. The Photoconductivity in a Surface-type Cell
Authors: Okamoto Kenichi , Kusabayashi Shigekazu , Mikawa Hiroshi
Published: July 2006

The photoconductivity of poly-N-vinylcarbazole in a surface-type cell was measured both in a high vacuum and in the air. Fresh films showed a large photocurrent in the lower π-π* absorption region and a small photocurrent in the visible region. The threshold of the photocurrent was found at about 600 mμ. By heat treatment or by pre-irradiation with UV-light or γ-ray, the photocurrent increased throughout the spectral region and its threshold shifted to a longer wavelength. Both the dark current and the photocurrent in the visible and the near IR regions must be due to the thermal or optical reexcitation of the trapped carriers. The activation energies of the dark current (0.4–1.3 eV) and the photocurrent (0.06–1.0 eV) differ according to the temperature range, the light wavelength, and the film history (whether fresh film or one of various pre-treated films). The activation energies are needed for carrier migration and can be explained by the “trapping conduction mechanism”.
The Structure and Reactivity of Nickel Hydroxide
Authors: Sakashita Masao , Sato Norio
Published: July 2006

This paper examines the correlation between the structure and the reactivity of nickel hydroxide, using X-ray diffraction, DTA, IR spectroscopy, and gravimetry during dehydration. The degree of crystallization of β-nickel hydroxide depends on the preparation conditions of the hydroxide. Highly-crystallized β-nickel hydroxide has “free” hydroxyl groups, as is to be expected from its brucite structure. Poorly-crystallized β-hydroxide, however, has “hydrogen-bonded” hydroxyl groups, this finding is in disagreement with a previous result that “hydrogen-bonded” hydroxyl groups were found to exist only in α-form nickel hydroxide. The dehydration of the hydroxide is shown to take place in first-order kinetics with an activation energy which increases as the crystallization extends.
Crystal Structure of the Potassium Salt of Chloranil
Authors: Konno Michiko , Kobayashi Hayao , Marumo Fumiyuki , Saito Yoshihiko
Published: July 2006

The crystal structures of K+(chloranil)− have been studied by X-ray diffraction. Several polymorphs were recognized, two of which (α- and β-forms) grew into comparatively good crystals. The α-form is orthorhombic, space group P212121 with unit cell dimensions: a=13.49, b=17.02, c=4.03 Å. The β-form is orthorhombic, space group P2212 with unit cell dimensions: a=14.13, b=17.35, c=3.71 Å. The structure of the α-form was deduced from the Patterson synthesis and refined by the block-diagonal least-squares method. The final R value was 0.13 for 146 observed reflections. Chloranil anions are stacked with equal intervals in the crystal, forming columns parallel to the c axis, the interplanar spacing being 3.47 Å. The electrostatic energy calculated by Evjen’s method was about −148 kcal/mol, indicating that the structure is essentially ionic.
The X-Ray Emission Spectra of the Compounds of Third-period Elements. VI. The Relationship between the Kα and Kβ Spectra
Authors: Takahashi Yoshihito
Published: July 2006

Data on the Kβ spectra for several compounds of silicon, aluminum, and sulfur are shown. The intensity of the Kβ′ line is affected not by the kinds of thrid-period atoms, but by their charges and by the kinds of ligand atoms. The degree of the contribution of each bonding group to the relative intensity of the Kβ′ line and to the chemical shift of the Kα1,2 lines are shown; they have additivity in the molecule. Therefore, the chemical shift of the Kα1,2 lines can be estimated from the molecular structural formula; the charge of the atom can also be estimated.
Ionic Equilibria in Mixed Solvents. VIII. Solvent Effects on the Dissociation of Diprotic Acids in Aqueous Methanol Mixtures
Authors: Ohtaki Hitoshi , Maeda Masunobu
Published: July 2006

Dissociation constants of protonated 1,6-hexanediamine, 1,8-octanediamine, 1,10-decanediamine, 1,11-undecanediamine, and 1,12-dodecanediamine in aqueous mixtures of 0 to 90% (w/w) methanol were determined potentiometrically at 25°C, 0.1 M sodium chloride being used as an ionic medium. Values of pK2–pK1 of diamines were practically independent of the solvent composition in contrast to those of dicarboxylic acids, which increase monotonously with methanol concentration. Variations of pK1, pK2, and pK2–pK1 of diamines with solvent composition were discussed in comparison with those of dicarboxylic acids.
The Emission Spectra of Hexamminechromium(III) Hexacyanocobaltate(III), [Cr(NH3)6][Co(CN)6]
Authors: Kataoka Hiroshi
Published: July 2006

Spin-forbidden absorption bands of K3[Co(CN)6] were reexamined employing conventional transmission spectroscopy, diffuse reflectance spectroscopy, and microspectrophotometry. A small but very distinct shoulder (ε≈0.3–0.4) obtained at a low temperature at 26000 cm−1 was assigned to the 3T1g←1A1g transition. Another very small band (ε≈0.001) at 16300 cm−1 was probably due to an impurity. The emission spectra of K3[Co(CN)6] powder in the temperature range from room temperature to that of liquid hydrogen were observed by means of a modified Hitachi 203 fluorescence spectrophotometer. The broad emission band at room temperature showed some vibrational structures at low temperatures. The emission spectra of powders of [Cr(NH3)6](NO3)3 and [Cr(NH3)6][Co(CN)6] were also measured. The following results were obtained: i) Similar emission spectra, which seemed to originate from [Cr(NH3)6]3+, were observed with both complexes [Cr(NH3)6](NO3)3 and [Cr-(NH3)6][Co(CN)6] using mercury lines at 313, 365, and 435 nm for excitation, ii) With 254 nm excitation, such emission spectra as i) were not observed with [Cr(NH3)6](NO3)3, but the same emission spectra as in i) were observed with [Cr(NH3)6][Co(CN)6]. iii) The ratio of the emission intensities at 15000 cm−1 with 435 and 313 nm excitations was 1:0.25–0.30 for [Cr(NH3)6](NO3)3, but it was 1:1.5–1.7 for [Cr(NH3)6][Co(CN)6]. From these results, it was presumed that, in [Cr(NH3)6][Co(CN)6], there occurred an energy transfer from the complex anion to the complex cation. Furthermore, emission spectra were observed with [Cr(NH3)6](ClO4)3 and the equimolar mixture of complex salts [Cr(NH3)6](ClO4)3–K3[Co(CN)6] and [Cr(NH3)6](NO3)3–K3[Co(CN)6] for the purpose of confirming the energy transfer in [Cr(NH3)6][Co(CN)6]. The temperature dependence of the emission intensity was also discussed.
Phase Equilibria in the V2O3–VO2 System at High Temperatures
Authors: Endo Hozumi , Wakihara Masataka , Taniguchi Masao , Katsura Takashi
Published: July 2006

The phase equilibria in the V2O3–VO2 system were established at 1307 K by varying the oxygen partial pressures from 10−4 to 10−12 atm. Eight phases, V2O3, V3O5, V4O7, V5O9, V6O11, V7O13, V8O15, and VO2, were observed under these experimental conditions. Vanadium sesquioxide has an extensive range of solid solutions at 1307 K. Also, the phase diagram and isobaric lines of oxygen partial pressure in the V2O3 phase were determined from 1307 to 1700 K on the basis of our present and previous studies. Quenching and thermogravimetric methods were applied under a controlled oxygen atmosphere. The oxygen partial pressures were determined by means of a solid electrolyte cell composed of (ZrO2)0.85(CaO)0.15. The standard free energies of the oxidation of V2O3 to V3O5, of V3O5 to V4O7, of V4O7 to V5O9, of V5O9 to V6O11, of V6O11 to V7O13, of V7O13 to V8O15, and of V8O15 to VO2 were determined on the basis of the equilibrium oxygen partial pressure at 1307 K. The enthalpy and entropy data of the oxidations of V2O3 to V3O5 and of V3O5 to V4O7 were evaluated from the oxygen partial pressures on the basis of the present results and previous data.
Some β-Diketone Chelate Complexes with Uranium(IV), Thorium(IV), and Cerium(IV). Preparation and IR Spectra
Authors: Yoshimura Tetsuhiko , Miyake Chie , Imoto Shosuke
Published: July 2006

The tetrakis β-diketonates of U(IV), Th(IV), and Ce(IV) with acetylacetone, trifluoroacetylacetone, hexafluoroacetylacetone, benzoylacetone, dibenzoylmethane, benzoyltrifluoroacetone, and thenoyltrifluoroacetone have been prepared and their infrared spectra measured in the range 4000–200 cm−1. In every chelate, a strong, broad and metal sensitive band related to the M–O stretching mode was found in the 200–250 cm−1 region.
Studies on Mass Spectrometry of Metal Chelates. I. Mass Spectrometry of Oxine Metal Chelates
Authors: Kidani Yoshinori , Naga Shinobu , Koike Hisashi
Published: July 2006

With a view to applying mass spectrometry to the studies of metal chelates, we investigated the mass spectrometry of divalent metal oxinates (Mn, Co, Ni, Cu, Zn, Pb, and Pd). The molecular ion I, whose peaks correspond to the metal chelates in a 2: 1 ratio, were observed in every spectrum. A loss of 144 mass units from I, corresponding to one molecule of coordinated oxine, occurred to afford the fragment ions II of metal chelates in a 1: 1 ratio. The peaks of the fragment ions III which lost 28 mass units (CO) from II were observed for Mn, Co, Ni, Cu, and Pd chelates. In order to study the stability of metal chelates against electron impact, special attention was paid to the peaks of I and II, which are supposed to be affected strongly by the d-electron number, electronegativity, ionization potential, and the ionic radius of central metal atoms. The intensity ratios of peaks I to II were obtained in the order Zn>Ni>Pd≈Co>Mn>Cu>Pb. It has been shown that the intensity ratios are related to the charge-radius ratio (e⁄r) of central metal atoms and the stability constants (logk2) of oxine metal chelates.
Polarographic Study of Monosaccharides in Unbuffered Solution and Its Application to the Determination of the Mutarotation Rate Constants
Authors: Ikeda Tokuji , Senda Mitsugi
Published: July 2006

The polarographic behavior of monosaccharides in unbuffered neutral solution was investigated. The limiting current was ascertained to be an autocatalytic current which could be caused by the production of hydroxyl ion at the electrode surface. Equations for the characteristic limiting current and for the shape of current-potential curve were derived by use of the reaction layer concept. Experimental results for d-glucose, d-galactose, and d-xylose were fairly well expressed by these equations. The wave can also be applied to the determination of the mutarotation rate constants of monosaccharides, the values obtained (d-glucose: 0.53×10−3 s−1, d-galactose: 0.54×10−3 s−1, and d-xylose: 1.31×10−3 s-−1) being in fairly good agreement with those obtained by the polarimetric method (d-glucose: 0.4×10−3 s−1, d-galactose: 0.5×10−3 s−1, and d-xylose: 1.3×103 s−1).
The Metal Ammine Cyanide Aromatics Clathrates. XVI. Wide-Line NMR Studies of the Three-Spin Systems of Ligand Ammonia in Paramagnetic Hofmann-type Clathrates
Authors: Nakano Taku
Published: July 2006

Wide-line NMR studies of ammonia molecules in Hofmann-type clathrates with the general formula of M(NH3)2M′(CN)4·2C6D6 are reported. In the Hofmann-type clathrates, two ammonia molecules coordinate to the paramagnetic metal ions in trans positions and have only a slight interaction with each other. In powder samples, the proton NMR spectra of ammonia give fine structures with three components, which are caused by dipolar interaction between protons of the rotating triangular three-spin system. The signals shift to the higher-field side under the influence of the paramagnetic moments of the metal ions. The temperature dependence of the shifts and line shapes, where M is iron(II), cobalt(II), nickel(II), and copper(II), will be reported on. No rigid ammonia was found, even at the temperature of liquid nitrogen.
Polarographic Reductions of Some Alkali and Alkaline Earth Metal Ions in Dimethylacetamide. Effect of Cation of the Supporting Electrolyte
Authors: Izutsu Kosuke , Sakura Sachiko , Fujinaga Taitiro
Published: July 2006

Polarographic reductions of lithium, barium, strontium, and calcium ions in dimethylacetamide (DMA) have been examined in the supporting electrolytes of various kinds of tetraalkylammonium perchlorates. As having been observed in hexamethylphosphoramide, the reductions of these metal ions in DMA are influenced significantly by the cation of the supporting electrolyte. When the cation of the supporting electrolyte is small in size and easily adsorbed onto the negatively charged electrode surface, as in the case in Et4NClO4, the reductions of these metal ions are difficult and they either do not occur at all until the reduction of the supporting electrolyte itself or, if they occur, the limiting currents are small and controlled by some preceding processes. With the increase of the cationic size of the supporting electrolyte, the reductions become much easier. Thus, in Bu4NClO4 and in Hex4NClO4, these metal ions are reduced almost reversibly. The effect of cation of the supporting electrolyte on the reduction of lithium ion has also been examined briefly in dimethylsulfoxide, dimethylformamide and propylenecarbonate.
Autoxidation of Trimethyl Phosphite Initiated by One-Electron Transfer from Phosphite to Quinones
Authors: Ogata Yoshiro , Yamashita Mitsuji
Published: July 2006

The reaction of trimethyl phosphite (I) with acenaphthenequinone (II) under air affords quantitatively trimethyl phosphate (III) and 1:2 adduct (IV), which was converted into δ-lactone (V) and III by addition of water, while only IV was obtained quantitatively under N2 atmosphere. ESR and UV spectra, decolorization of 1,1-diphenyl-2-picrylhydrazyl (DPPH), and initiation of styrene polymerization suggest the transient formation of radical ions VI and VII. The rate law for the autoxidation of I is expressed as: v=k[I][II]0.7−1.0. The reaction in chloroform proceeds faster than that in dioxane. The reaction of I with chloranil is much slower, and no reaction occurs with phenanthrenequinone and anthraquinone which have low reduction potentials. A mechanism which involves one-electron transfer from phosphite to acenaphthenequinone followed by autoxidation was proposed for the reaction under air.
Measurement of Negative Ions Formed by Electron Impact. IX. Negative Ion Mass Spectra and Ionization Efficiency Curves of Negative Ions of m⁄e 25, 26, 27, 38, 39, 40 and 50 from Acrylonitrile
Authors: Tsuda Satoru , Yokohata Akira , Umaba Toshikatsu
Published: July 2006

Negative ion mass spectra of acrylonitrile were measured for the electron energies of 80, 40 and 9.5 eV. Emphasis was laid on the abundance of the negative ions relative to the positive ions measured for the energies of 80, 40 and 15 eV, respectively. The ionization efficiency (IE) curves were also determined up to 25 eV for the ions of m⁄e 25(C2H−), 26(CN−), 27(HCN−), 38(C2N−), 39(CHCN−), 40(CH2CN−) and 50(C3N−). The electron impact of 80 eV and 40 eV gave almost the same distribution of m⁄e for negative ion mass spectra. Besides the most intense peak of CN− ions, relatively strong peaks of C3N−, C2H−, C2− and C2N− ions were observed. In 9.5 eV, CN− ions predominated over other ions. Yields of the ions showed a good linearity against the pressure in the range used for usual chemical analysis, irrespective of electron energy. Comparison of the yield of CN− ions with that of C2H3CN+ gave the values 1.2×104 and 1.9×104 for C2H3CN+/CN− at 80 eV and 40 eV, respectively, and 47.6 at 9.5 eV (15 eV for the positive ions). The plausible reaction schemes expected to occur at each onset observed in the IE curves were also sought thermochemically by using ΔHf values of the reactant and products. A value \gtrsim2 eV was obtained for the electron affinity of C2H.
Time-Resolved Fluorescence Studies on the Dual Fluorescence Process of p-(Dimethylamino)benzonitrile
Authors: Nakashima Nobuaki , Inoue Hidetoshi , Mataga Noboru , Yamanaka Chiyoe
Published: July 2006

Time-resolved fluorescence spectra and the fluorescence rise and decay curves have been measured for p-(N,N-dimethylamino)-benzonitrile. The results demonstrate the relaxation process to be due to the interaction between the solvent and the 1La state of the solute, leading to dual fluorescence.
Mass Spectrometric Study of the Primary Processes in Photochemical Reactions I. Photodecomposition of 1,1′-Azopropane
Authors: Yamashita Shigeru , Hayakawa Teruo
Published: July 2006

Primary processes of the photolysis of 1,1′-azopropane were studied using a high intensity light beam and a collision-free photochemical reactor incorporated in the ion-source of a mass spectrometer. The photofragments produced by the following three one-bond fission primary processes were found.

& CH_3CH_2CH_2N_2CH_2CH_2CH_3+hν→CH_3CH_2CH_2N_2CH_2+CH_2CH_3\labeleq1

& CH_3CH_2CH_2N_2CH_2CH_2CH_3+hν→CH_3CH_2CH_2N_2+CH_2CH_2CH_3\labeleq2

& CH_3CH_2CH_2N_2CH_2CH_2CH_3+hν→2CH_3CH_2CH_2N\labeleq3

The lifetime of these photofragments seems to be longer than 50 μs considering the experimental conditions.
Studies on Intermolecular Complex Formation. IV. Crystal Structure of Cytosine-Resorcylic acid 2:1 Complex monohydrate
Authors: Tamura Chihiro , Sato Sadao , Hata Tadashi
Published: July 2006

The crystal and molecular structure of a cytosine and resorcylic acid complex monohydrate has been solved by the direct method. The molecular complex is formed by two moles of cytosine and one mole of resorcylic acid. The crystals are monoclinic, with a space group of P21/n, and with a=8.335, b=20.605, c=10.159 Å, and β=95.5°. The final R-factor for 1820 reflections is 0.100. Resorcylic acid is hydrogen-bonded to one of the cytosine molecules with one hydrogen bond, and the two cytosine molecules with one hydrogen bond, and the two cytosine molecules are associated with three hydrogen bonds in a system similar to that of the guanine-cytosine hydrogen bond in the Watson-Crick model.
Investigation on Low-spin Cobalt(II) Complexes. III. Structural, Optical and Magnetic Properties of Five-coordinate Complexes
Authors: Nishida Yuzo , Shimohori Hideharu
Published: July 2006

ESR and reflectance spectra of low-spin five-coordinate cobalt(II) complexes [CoXdpe2]Y, where dpe represents 1,2-bis(diphenylphosphino)ethane and X,Y are Cl−, Br−, NCS−, NO3− and ClO4− anions, were measured. From the results it was inferred that the structures of [CoCldpe2]ClO4 and [CoBrdpe2]ClO4 are distorted trigonal bipyramids whereas those [CoNCSdpe2]ClO4 and [CoNO3dpe2]NO3 are square pyramids.
The Crystal Structure of (−)589-Acetylacetonatobis(trimethylenediamine)cobalt(III) Arsenic(V) (+)-Tartrate Monohydrate
Authors: Matsumoto Keiji , Kawaguchi Hiroshi , Kuroya Hisao , Kawaguchi Shinichi
Published: July 2006

The crystal structure of (−)589-[Co acac tn2][As-(+)-tart]2·H2O has been determined by the X-ray diffraction method. The crystals are monoclinic, with lattice constants of a=12.02(1) Å, b=13.73(2) Å, c=9.02(1) Å, and β=107.4(3)°, and with the space group of P21, containing two formula units in a cell. The structure was determined by the application of Patterson and Fourier techniques and was refined by the least-squares method to an R factor of 10.4%. The absolute configuration of (−)589-[Co acac tn2]2+ can be denoted as Δ. The two Co-tn chelate rings assume the chair form, and the Co-acac chelate ring is almost planar. The geometry of [As-(+)-tart]22− is identical with that of [Sb-(+)-tart]22−.
A Kinetic Study of the Ligand Substitution Reaction of Tetramethylenediaminetetraacetatocobaltate(II) with Trimethylenediaminetetraacetate
Authors: Ogino Hiroshi , Watanabe Toshiyuki , Chung Jong-Jae , Tanaka Nobuyuki
Published: July 2006

The kinetics of the ligand substitution reaction of tetramethylenediaminetetraacetatocobaltate(II)(cobalt(II)–TDTA) with trimethylenediaminetetraacetate (TRDTA) was investigated by two different polarographic methods. The kinetic data at pH 4.9 to 5.6 were obtained by means of a conventional method in which the reaction was initiated by the mixing of two reactant solutions and was followed polarographically. However, this method could not be applied to solutions with pH values lower than 4.9, for the rate of the reaction is immeasurably fast in such a low pH region. The kinetic data at pH values down to 3.7 were obtained by analyses of the polarographic current which was observed in solutions containing TRDTA and the substitution-inert cobalt(III)–TDTA complex. From these data, it was found that the reaction proceeds through four simultaneous reaction paths, two paths of which are the nucleophilic substitution reactions, while the others are the dissociation reactions of cobalt(II)–TDTA complex ions.
Structural Studies of Tryptophan Metabolites by X-ray Diffraction Method. II. The Crystal and Molecular Structure of Tryptamine Hydrochloride
Authors: Wakahara Akio , Fujiwara Takaji , Tomita Ken-ichi
Published: July 2006

The crystal structure of tryptamine hydrochloride has been solved by the application of the symbolic addition method, and refined by successive Fourier syntheses and least-squares procedures. The crystals are orthorhombic, space group Pbca, with lattice parameters a=8.545, b=10.025 and c=24.252 Å. All the positions of hydrogen atoms were found in the difference Fourier map and included in the refinement. The ethylamine side chain bound to the indole ring is in a folded configuration as found in the crystal structure of serotonin picrate monohydrate. A weakly basic nitrogen atom of the indole ring takes part in the hydrogen bonding with the adjacent ion. Every chloride ion behaves as an acceptor for four hydrogen bonds. This is in line with the absence of any marked cleavage where indole rings are packed together to form a pleated sheet and a three-dimensional network structure is essentially stabilized by the hydrogen bond formation.
Photochemical Reaction of Diaryl Thioketones in Ethereal Solutions. A Stable Transient Free-Radical
Authors: Kito Noboru , Ohno Atsuyoshi
Published: July 2006

Photochemical reactions of thiobenzophenone and its 4,4′-dimethoxy derivative in ethereal solutions such as tetrahydrofuran and diethyl ether have been studied by means of product analyses and ESR spectroscopy. It was found that the reaction involves quite stable transient free-radicals of the type Ar2CSR. The efficiency of free-radical trapping by diaryl thioketones and the reaction mechanism are discussed.
Kinetic Study of Triplet–Triplet Energy Transfer in Fluid Solution by Means of Laser Pulse Photolysis
Authors: Takemura Takeshi , Baba Hiroaki , Fujita Masahisa
Published: July 2006

The kinetics of triplet-triplet (T-T) energy transfer in fluid solution has been studied by means of laser pulse photolysis with acetophenone as the energy donor and naphthalene as the acceptor. Decay curves of phosphorescence of the donor and rise-and-decay curves of sensitized T-T absorption of the acceptor were obtained. These were analyzed to determine the unimolecular and bimolecular rate constants (denoted by k1 and k2 respectively) for the deactivation processes of the triplet state of donor or acceptor and the rate constant (kt) for the T-T energy transfer. In isooctane at room temperature these rate constants were found to be: k1=0.67×106 sec−1 and k2=2.0×1010 M−1 sec−1 for acetophenone, k2′=1.6×1010 M−1 sec−1 for naphthalene, and kt=1.0×1010 M−1 sec−1. The kt value obtained from the donor phosphorescence is in good agreement with that from the acceptor T-T absorption. The experimental results suggest that T-T transfer and T-T annihilation processes are not strictly diffusion-controlled.
Near-infrared Spectroscopic Studies of the States of Water in Lyotropic Liquid Crystals
Authors: Aizawa Masuo , Suzuki Shuichi
Published: July 2006

The states of water in lyotropic liquid crystals of the polyoxyethylene–nonylphenylether and water system were investigated by means of near-infrared spectroscopic measurements. The states of water were classified into nonbonded, singly-hydrogen-bonded, and doubly-hydrogen-bonded states, and their relative concentrations were calculated from the intensities of the combination bands of 2ν1+ν3 and ν1+ν2+ν3 in the temperature range from 25 to 50 °C. An increase in the hydrogen-bonded water species was found for the liquid crystal. Furthermore, the nonbonded and singly-hydrogen-bonded water species decreased, while the doubly-hydrogen-bonded water species increased in the liquid crystal structure, as compared with ordinary water. The structural properties of the liquid crystal are discussed.
Relationship between Self-Diffusion and Interdiffusion in Gaseous Systems
Authors: Hirakawa Hiromasa , Kamei Yoshinobu , Sugisaki Masayasu , Oishi Yasumichi
Published: July 2006

Self-diffusion coefficients of oxygen and interdiffusion coefficients were measured for the O2–He system at 25 °C under 760 Torr. The interdiffusion coefficients obtained were compared with theoretical values calculated by the kinetic theory and by Darken’s phenomenological theory. The phenomenological equation was tested in comparison with the kinetic theory by making use of the results and the data reported by other investigators. A criterion determining the magnitude or error of the phenomenological equation was given.
The Magnetic Properties of Verdazyl Free Radicals. III. The Anomalous Magnetic Behavior of Symmetrical Triphenylverdazyl
Authors: Azuma Nagao , Yamauchi Jun , Mukai Kazuo , Ohya-Nishiguchi Hiroaki , Deguchi Yasuo
Published: July 2006

The static magnetic susceptibility and the ESR spectra from 1.6 to 300 K have been measured on a powder sample of the titled free radical. The broad maximum in the susceptibility which indicates an antiferromagnetic interaction has been observed at 6.9 K. The broadening of the ESR absorption line and the shift of the g-value have been found in the temperature region below Tmax, in which the susceptibility reached its round maximum. There appeared anomalies in the slope of the susceptibility, the linewidth, and the g-value versus temperature curves in the vicinity of 1.7 K. These anomalies may imply a magnetic-phase transition from the short-range ordered state to the long-range ordered state at about 1.7 K. The existence of a ferromagnetic interaction between the magnetic chains in the triphenylverdazyl radical solid is discussed on the basis of the susceptibility, the spin distribution, and the crystal structure. It is understood qualitatively that the radical with a negative spin density has a latent ferromagnetic interaction in or between the magnetic chains, and that the obsrevation of this interaction greatly depends upon the molecular and crystal structure.
Interaction of Bovine Serum Albumin with Detergent Cations
Authors: Kaneshina Shoji , Tanaka Mitsuru , Kondo Tatsuhiko , Mizuno Tomoaki , Aoki Koichiro
Published: July 2006

The binding isotherms of bovine serum albumin (BSA) with cationic detergents, decyltrimethylammonium bromide, dodecyltrimethylammonium bromide, and tetradecyltrimethylammonium bromide have been determined at temperatures 8 and 25 °C for pH 6.8. The isotherms have also been determined at pH 3.0 and 25 °C. The effect of KBr on the binding of dodecyltrimethylammonium bromide to BSA has been examined at 25 °C for pH 6.8. The results obtained are as follows. (a) The average number of detergent cations bound, \barv, increased with the increase in the length of hydrocarbon chain, (b) the standard free energy changes −ΔG°, calculated from the intrinsic association constants K, were comparable with the cohesive energy change when one methylene group is transferred from the aqueous phase to the hydrocarbon environment on micellization, (c) values of \barv at pH 3.0 differ only slightly from those at pH 6.8 in a wider range of detergent concentration, and (d) the presence of the salt shifted the binding isotherms to the lower detergent concentrations. These results are discussed as regards the nature of micellization of detergents.
Kinetic Studies of Photosensitized Oxidation through Semioxidized Eosine in an Aqueous Solution
Authors: Usui Yoshiharu , Enokido Haru
Published: July 2006

The rate constant for an electron transfer reaction between triplet eosine and potassium tris(oxalato)cobaltate(III) was estimated. The experimental results from flash photolysis indicate that a transient semioxidized eosine exists in a free state. When a substrate was added to the deaerated eosine and complex solution at an optimum concentration, the original dye was restored by electron transfer from a substrate to the semioxidized eosine, sensitized oxidation occurring efficiently. Choosing indole and its derivatives as a substrate, we have obtained the elementary rate constants of the eosine recovery process.
Studies of Photochemical Reactions Using Organic Photosensitizers. III. Direct Photolysis and Biacetyl-photosensitized Decomposition of Azopropanes
Authors: Yamashita Shigeru , Okumura Kuniyasu , Hayakawa Teruo
Published: July 2006

The direct photolyses in the two wavelength regions and the biacetyl-photosensitized decomposition have been studied for l,l′-azo-n-propane and 2,2′-azo-isopropane. The value of kd/kc, the ratio of the disproportionation rate to the combination rate of free radicals, has been found to be slighlty dependent on the exciting wavelength as for n-propyl and isopropyl radicals. The higher the exciting energies, the larger the ratio kd/kc. From the quenching study of biacetyl phosphorescence, it was found that the energy of the excited biacetyl molecule was transferred to the azopropane molecule at every collision.
The Electrochemical Behavior of the Low-valent Transition Metal Complexes. II. Iron(0)-2,2′-Bipyridine Complexes
Authors: Misono Akira , Uchida Yasuzo , Hidai Masanobu , Yamagishi Takamichi , Kageyama Hironori
Published: July 2006

The electroreduction reaction of the zero-valent iron-2,2′-bipyridine complexes (Fe(bipy)2 and Fe(bipy)3) was studied in a hexamethylphosphoric triamide solution by polarography and ESR measurements. In the polarography, Fe(bipy)2 was first reduced at a very less negative potential (E1⁄2=−0.76V vs. Hg pool) than the first wave potential of free bipyridine (−2.37 V vs. Hg pool). In the presence of excess bipyridine, Fe(bipy)2was first reduced at −1.10 V vs. Hg pool corresponding to the second reduction step of the solution of Fe(bipy)2. The visible spectra of the solution of Fe(bipy)2 in the presence of excess bipyridine was different from that of the solution of Fe(bipy)2 only. The signal with hyperfine structure attributable to the anion radical of bipyridine was observed by means of ESR analysis of the solution electrolyzed at the potential corresponding to the second reduction step. From these results, it was concluded that [Fe(bipy)(HMPT)m] was reduced at the first step, and [Fe(bipy)2(HMPT)] was reduced at the second.
Isotopic Exchange Kinetics between Dibenzoylmethane-14C and Its Tris-type Complex with Aluminium (III) in Tetrahydrofuran
Authors: Matsuzawa Kazuyo , Saito Kazuo
Published: July 2006

Isotopic exchange kinetics between [Al(dbm)3] and Hdbm–14C (dbm−, anion of dibenzoylmethane in enol form) has been studied in tetrahydrofuran (THF) at 30 to 55°C. During several half lives the McKay plot gives straight lines, the AB spectrum remaining unchanged. The rate is very small in the absence of catalysts, and accelerated by water and trichloroacetic acid, but not by weak acids and pyridine. The rate is expressed by

R = [complex](k_2[H_2O]+k_3’[acid]+k_3[acid][H_2O])

The Arrhenius plots of k2, k3′, and k3 give an equal Δ\eweq value 25.6 kcal/mol. It appears one of the ligands is present as unidentate in the intermediate state, and the break of the remaining bond is the rate-determining step.
Linear Conjugated Systems Bearing Aromatic Terminal Groups. XIV. On the Electronic Spectral Regularity of α,ω-Diarylpolyenes
Authors: Akiyama Shuzo , Takeuchi Yasuhira , Yasuhara Akio , Nakagawa Masazumi , Nishimoto Kichisuke
Published: July 2006

The bathochromic shift of the longest wavelength absorption maxima (λ) of several series of polyenes along with the increase in number of ethylenic double bond (n) can be expressed excellently by the empirical formula λ=Anx+B. The value of x varies from 0.5 to 0.8 [0.5≤x≤0.8] depending on the nature of terminal groups and the position of linking of polyene chain to terminal aryl nucleus, being x=0.5 in the case of parent polyenes (I) and x=0.8 for di(3-phenanthryl)- (VI) and di(2-fluorenyl)polyenes (VII). The linear relationship could be reproduced fairly well by the HMO method using the usual bond-alternation approximation (βc=c=1.1β; βc-c=0.9β; βc=c=β. C=C denotes aromatic double bond). The calculation based on a modified bond-alternation approximation (βc=c=[1+0.5⁄(n+4)]β; βc-c=[1−0.5⁄(n+4)]β; βc=c=β) which is analogous to that successfully applied to diarylpoly-ynes did not reproduce the spectral regularity of diarylpolyenes. This seems to offer further support for the pertinence of assumption of increasing contribution of cumulenic structure in diarylpolyenes along with the increase in n.
Stereospecific and Stereoselective Reactions. II. Preparation of Esters of N-Phthaloyl-α-amino Acid from Esters of α-Hydroxy Acid
Authors: Wada Makoto , Sano Takashi , Mitsunobu Oyo
Published: July 2006

Functional selectivity and stereospecificity of the intermolecular dehydration between alcohols and phthalimide (III) by means of diethyl azodicarboxylate (I) and triphenylphosphine (II) was examined. The reaction of allyl alcohol, 2-chloroethanol or (±)-ethyl lactate with I, II, and III led to the formation of corresponding N-alkylphthalimide. The reaction was further applied to the synthesis of esters of N-phthaloyl-α-amino acid. (S)-(−)-ethyl 2-hydroxy-3-phenylpropionate was converted into (R)-(+)-N-phthaloylphenylalanine ethyl ester with high stereospecificity.
New Furanoeremophilane Derivatives from Farfugium japonicum Kitamura
Authors: Nagano Hajime , Tanahashi Yoshiaki , Moriyama Yoshihiko , Takahashi Takeyoshi
Published: July 2006

Five new furanoeremophilane derivatives, I, II, III, IV, and V, have been isolated from Farfugium japonicum Kitamura, and their structures have been determined. Conformations of some furanoeremophilane derivatives are discussed.
Transylidations of Stable Sulfonium Ylids
Authors: Matsuyama Haruo , Minato Hiroshi , Kobayashi Michio
Published: July 2006

In the presence of a dialkoxy disulfide, sulfonium bis(methoxycarbonyl)methylids underwent transylidation with a dialkyl sulfide or pyridine at 35 °C. Thiocyanogen and benzoyl disulfide showed a similar catalytic effect. The kinetics of this reaction were investigated, and its mechanism was discussed.
Thermodynamic Properties of Moderately-concentrated Poly (γ-benzyl-l-glutamate) Solutions
Authors: Okamoto Akio , Kubo Kenji , Ogino Kazuyoshi
Published: July 2006

The osmotic pressures for poly(γ-benzyl-l-glutamate) solutions in ethylene dichloride and chloroform were measured at 29 °C in the concentration range of 2–15 vol % polymer. The osmotic pressures increased monotonously with an increase in the concentration. No evidence was found for the coexistence of two phases. The results are compared with the theory of the solutions of rodlike molecules. The values of the thermodynamic interaction parameter, χ, for the systems were found to be 0.44–0.47 in the concentration range lower than 6.5 vol% polymer, where the solutions must be isotropic.
Radiation Chemical Studies with Cyclotron Beams. III. The Heavy-ion Radiolysis of Liquid Aliphatic Ketones
Authors: Matsui Masao , Imamura Masashi
Published: July 2006

The liquid-phase radiolysis of acetone, methyl ethyl ketone, and diethyl ketone with 4He–, 12C–, and 14N–ions was carried out with the intention of discovering the specific reactions taking place in a very high LET region. The heavy ions were accelerated at various energies with an IPCR cyclotron, the LET of which was up to 80 eV/Å. The radiolytic yields of the main gaseous products, hydrogen and carbon monoxide, were found to increase appreciably with an increase in the LET and to reach the maximum values in the LET region between 50 and 70 eV/Å. The ratios of the two yields, G(H2)/G(CO), also increase substantially with an increase in the LET. These results, as well as the variations in the yields of saturated and unsaturated hydrocarbons, appear to indicate a thermal-spike effect which may bring about the thermal decomposition of free radicals, giving rise to the enhanced G(H2) and G(CO) values in the high LET region.
Temperature Dependence of the Lattice Vibrations of Triglycine Sulfate
Authors: Kaneko Norio , Takahashi Hiroaki , Higasi Keniti
Published: July 2006

Far infrared spectra from 400 to 30 cm−1 of triglycine sulfate and its deuterated analogue were measured and the bands due to the librational modes of glycine molecules were identified. Polarized Raman spectra below 300 cm−1 of triglycine sulfate single crystals were measured and the symmetry species of the observed lattice vibrations were determined. Temperature dependence of the lattice vibrations was examined. Significant changes were detected in both infrared and Raman spectra on crossing the Curie temperature, indicating a flipping motion of glycine I in the paraelectric phase and suggesting the ferroelectric transition in triglycine sulfate to be of an order-disorder type.
Interactions of β-Naphthol and β-NaphthyIamine in Their Excited Singlet States with Triethylamine
Authors: Matsuzaki Akiyoshi , Nagakura Saburo , Yoshihara Keitaro
Published: July 2006

Proton donor-acceptor interactions in excited states were studied by measuring mainly time-resolved fluorescence spectra for β-naphthol–TEA in toluene and in acetonitrile, and for β-naphthylamine–TEA in nonpolar mixed solvents. The Stern-Volmer relation was found to be satisfied for β-naphthol–TEA in toluene. The rate constant and activation energy of hydrogen bond formation in the excited state of this system were obtained to be 2.2×109 M−1 s−1 at 30 °C and 1.6 kcal/mol, respectively, indicating that the process is diffusion-controlled. The time dependences of the intensities of the fluorescence bands due to the free and complexed β-naphthol were measured with the solutions containing various concentrations of triethylamine in acetonitrile. From the analysis of the result, it is shown that this system is led to the ion-pair formation via the hydrogen-bonded species in the excited state. For β-naphthylamine–TEA in nonpolar mixed solvents, the bands due to hydrogen-bonded species in the ground and excited states were observed at 370 and ∼390 nm in the absorption and fluorescence spectra, respectively.
Dehydrogenation of 2-(1-Cyclohexenyl)cyclohexanone with Palladium Catalyst
Authors: Imafuku Kimiaki , Oda Junko , Itoh Kenshi , Matsumura Hisashi
Published: July 2006

The dehydrogenation reaction of 2-(1-cyclohexenyl)cyclohexanone was carried out in the presence of 5% palladium-on-charcoal at temperatures 280, 300, and 320 °C, the reaction time being 1/2—8 hr. o-Cyclohexylphenol and o-phenylphenol were obtained as dehydrogenation products, and dibenzofuran as the cyclization product via  o-phenylphenol. In a short reaction time, 2-cyclohexylcyclohexanone was formed together with the dehydrogenation products. The compound disappeared, the amount of two phenols and dibenzofuran increasing with reaction time. The dehydrogenation process is discussed.
Regio- and Stereo-selectivities in the Epoxidations of Limonene, endo-Dicyclopentadiene, and exo-Dicyclopentadiene
Authors: Sato Tadashi , Murayama Eigoro
Published: July 2006

The regio- and stereo-selectivities were observed in the radical and peracid epoxidations of limonene, endo-, and exo-dicyclopentadienes. The observations were considered in view of the proposed mechanisms for these reactions.
The Photo-Fries Rearrangement of Aryloxy-1,3,5-triazines
Authors: Ohto Yukio , Shizuka Haruo , Sekiguchi Shizen , Matsui Kohji
Published: July 2006

Aryloxy-s-triazines gave o- and/or p-hydroxyaryl-s-triazines upon irradiation; however, from arylamino-and arylthio-s-triazines, no photo-rearrangement product was obtained. The p-CH3, p-Cl, and p-OCH3 groups in the phenoxy moiety did not prevent the photoreaction of aryloxy-s-triazines; however, the p-CHO, p-COCH3, p-COOC2H5, and p-NO2 groups prevented the photoreaction. As to substituents in the s-triazine moiety, such groups as –Cl, –OCH3, –OC6H5, and –CH3 did not prevent the photoreaction; however, C6H5 and amino groups prevented the reaction. In the photolysis of 2,4-dimethoxy-6-(1-naphthyloxy)-s-triazine, 1-hydroxy-2-naphthyl- and 4-hydroxy-1-naphthyl-s-triazines were obtained, with the preferential formation of the former. On the other hand, from 2,4-dimethoxy-6-(2-naphthyloxy)-s-triazine, 2-hydroxy-1-naphthyl-s-triazine was obtained upon irradiation. In a similar manner, 2- and 4-acetyl-1-naphthols were obtained from 1-naphthyl acetate, and 1-acetyl-2-naphthol was isolated from 2-naphthyl acetate.
Addition of Methanesulfenyl Chloride and Sulfur Chloride to 1,4-Dimethyl-3,6-dimethylene-2,5-piperazinedione and Substitution of the Adducts
Authors: Yoshimura Juji , Sugiyama Yuichi , Matsunari Kenji , Nakamura Hiroshi
Published: July 2006

Addition of methanesulfenyl chloride or sulfur chloride to 3,6-dimethylene-(1a) and 3,6-dibenzylidene-1,4-dimethyl-2,5-piperazinediones (1b) gave the Markownikoff products. The addition of methanesulfenyl chloride to 1a proceeded stepwise within 1 hr, and gave a mixture of (Z,Z)-, (Z,E)-, and (E,E)-isomers of the corresponding 3,6-bis(methylthiomethylene) derivative, accompanied by gradual elimination of hydrogen chloride. 3,6-Di-chloro groups of the adduct were substituted with water, ethanethiol and ethanol to give the corresponding hydroxy, ethylthio, and ethoxy derivatives, respectively. A similar substitution with ethanedithiol and hydrogen sulfide followed by aeration gave 7,9-dimethyl-1,6-bis(methylthiomethyl)-8,10-dioxo-2,5-dithia-7,9-diazabicyclo[4,2,2]-decane and the corresponding 3,6-epitetrathio derivative, respectively. The same mode of reaction of sulfur chloride with 1a and 1b gave a few 1,6-disubstituted-7,9-dimethyl-8,10-dioxo-3,4-dithia-7,9-diazabicyclo[4,2,2]-decanes. Mass fragmentations of new compounds were also described.
Solvent Effects in Diazo-coupling Reactions
Authors: Hashida Y\={o}ji , Ishida Hiroki , Sekiguchi Shizen , Matsui Kohji
Published: July 2006

The kinetics of the diazo-coupling reactions of benzenediazonium fluoroborates with 1,3,5-trimethoxybenzene and 2-naphthol have been studied in non-aqueous media including both protic and dipolar aprotic solvents. In the case of the reaction with 1,3,5-trimethoxybenzene, no significant solvent effect on the reaction rate was observed. However, in the case of the reaction with 2-naphthol, the reaction rate was affected markedly by the solvent; in dipolar aprotic solvents, the reaction proceeded much faster than in protic solvents. The observed results are interpreted in terms of the difference in solvation toward the naphtholate ion.
Solution Properties of Phycocyanin. I. Studies of Dissociation-Association by Sedimentation Measurement
Authors: Saito Takahide , Iso Naomichi , Mizuno Haruo
Published: July 2006

The dissociation-association properties of phycocyanin, isolated from the red algae, “Porphyra tenera,” have been investigated by sedimentation velocity measurements at pH 6.8 and 5.4 and at the ionic strengths of 0.1 and 0.2. The sedimentation coefficient data indicated that the predominant component in the phycocyanin solution was a trimer at pH 6.8 and a hexamer at pH 5.4. The concentration dependence of the sedimentation coefficient for various hypothetic systems of the dissociation-association equilibrium of phycocyanin was simulated by a computer model. It was reasonable to consider, from the simulation, that the dissociation-association system of phycocyanin was trimer\ightleftharpoonsmonomer at pH 6.8 and hexamer\ightleftharpoonsmonomer at pH 5.4. The dissociation constant was calculated for each system. The value of the dissociation constant was 0.15×10−4 (g/dl)2 at pH 6.8 and an ionic strength of 0.1; 0.13×10−4 (g/dl)2 at pH 6.8 and an ionic strength of 0.2; 0.5×10−13 (g/dl)5 at pH 5.4 and an ionic strength of 0.1 and 0.1×10−13 (g/dl)5 at pH 5.4 and an ionic strength of 0.2. The dissociation constants decrease with an increase in the ionic strength in solution.