bluuebunny/crossref_metadata_2025 huggingface dataset:
Solubility of Alkyl Bromides in Aqueous Polymer Solutions
Authors: Okubo Tsuneo , Chen Shou-Xyng , Ise Norio
Published: July 2006

The solubility of alkyl bromides (alkyl : ethyl, n-propyl, n-butyl and n-amyl) in aqueous solutions of neutral polymers and polyelectrolytes was measured and discussed. The polymers used were polyacrylamide (PAAm), polyvinylalcohol(PVA), polyethyleneglycol (PEG), polyvinylpyrrolidone(PVP), polyethylenimine(PEI) and polyacrylic acid(PAA) and its salts. The solubility of alkyl bromide increased linearly with concentration of neutral polymer in the order PAAm>PVP∼PEI>PEG>PVA∼PAA. Sodium salt of PAA decreased the solubility of alkyl bromide, but organic salts of PAA such as tetraalkylammonium salts increased it. Using the equation In (So⁄S)=km2, the limiting Setchénow constant k was obtained for these systems. The results were accounted for in terms of the hydrophobic structural modifications of water and the direct dipole and/or hydrophobic interactions between solute and cosolute.
Comparison of the Conductance Equations of Fuoss-Onsager, Fuoss-Hsia and Pitts with the Data of Bis(2,9-dimethyl-1,10-phenanthroline)Cu(I) Perchlorate
Authors: Miyoshi Katsuhiko
Published: July 2006

Conductance equations derived by Fuoss-Onsager (1965), Fuoss-Hsia (1967) and Pitts (1953) were compared using the conductance data of bis(2,9-dimethyl-1,10-phenanthroline)Cu(I) perchlorate in acetonitrile, nitrobenzene and nitromethane at 25°C, which have relatively high dielectric constant. The chelate salt was found to be completely dissociated in these solvents. Though the Pitts equation was found to reproduce the data more satisfactorily than the Fuoss-Onsager (F–O) and the Fuoss-Hsia (F–H) equations, the derived distance of the closest approach a from the Pitts equation was unrealistically small for the bulky complex salt. It was shown that the F–H equation is preferable for the analysis of conductance data for both associated and unassociated electrolytes.
Kinetic Studies of the Dissociation and the Recombination Reaction in Aqueous Solutions of Monocarboxylic Acids by Means of Ultrasonic Absorption Measurements
Authors: Sano Takayuki , Miyazaki Tomohiro , Tatsumoto Nobuhide , Yasunaga Tatsuya
Published: July 2006

The ultrasonic absorptions were measured in aqueous solutions of acetic, propionic, butyric, valeric, and chloroacetic acids as a function of the pH over the frequency range from 1.5 to 220 MHz at 25°C. From the dependences of μ′max and fr on pH, it was deduced that the perturbation of the ionization equilibrium of acids was the cause of the excess absorptions in dilute aqueous solutions. The kinetic parameters thus calculated were compared with those obtained by other methods.
Spectrophotometric Study on the Extraction of the Ternary Complex Composed of Vanadium(V), 8-Hydroxyquinoline-5-sulfonic Acid and Zephiramine
Authors: Kambara Tomihito , Sugawara Masao
Published: July 2006

The ternary complex composed of vanadium(V),8-hydroxyquinoline-5-sulphonic acid (H2QS), and zephiramine (Z+Cl−) was extracted into chloroform. The absorption maxima of the ternary complex in the organic layer were 375 and 580 nm at pH 2.8 and 375 nm at pH 4.8. The optimum pH range for the extraction was 4.5–5.4. Beer’s law held for 1.29–35.6 μg of vanadium(V). The molar absorptivity of the complex was 0.99×104 cm−1 mol−1 l. The composition of the ternary complex was estimated to be [VO2+Z+(QS2−Z+)2]o and the extraction equilibrium was given by

VO2++2[(HQS−Z+)]o+Z++2OH−\ightleftharpoons[VO2+Z+(QS2−Z+)2]o+2H2O (1)

The logarithm of the equilibrium constant K of this equation was found to be 32.57±0.49.
The Reaction of Propargyl Compounds with Carbon Monoxide and Water in the Presence of Iron Carbonyl Catalyst
Authors: Wada Fumio , Matsuda Tsutomu
Published: July 2006

The reaction of propargyl alcohol as well as its acetate and methyl ether with carbon monoxide and water in the presence of ironpentacarbonyl-amine catalyst under oxymethylation conditions proved to proceed at a much faster rate than that of 1-butyn-4-ol, 1-pentyn-5-ol and alkylacetylenes accompanied by elimination of the functional groups at C-3 to give dimethyl methylsuccinate. 3-Methyl-1-butyn-3-ol and 1-ethynylcyclohexanol reacted in a similar manner, but gave mixtures of unsaturated monoesters and diesters, saturated and unsaturated. The faster rate of reaction and the product obtained were interpreted by a scheme involving a concerted attack of hydroirontetracarbonyl anion, HFe(CO)4−, at the terminal position to split off the group at C-3. The mononuclear hydrido anion was assumed to be an active catalytic species in the reaction on the basis of both the infrared spectra of the catalyst system under the reaction conditions and the efficiency of potassium hydroxide as a base component.
The Reactions of Stannic Halides with Some Triphenylphosphine, -arsine and -stibine-substituted Iron Carbonyls
Authors: Takano Tetsuo
Published: July 2006

The reactions of stannic chloride and bromide with triphenylphosphine, -arsine and -stibine tetracarbonyl iron(0) undergo oxidative-elimination reactions to afford new binuclear organometallic compounds in good yields; Fe(CO)4EPh3+SnX4→Fe(CO)3EPh3SnX4+CO (E=P, As, Sb; X=Cl, Br; Ph=C6H5), where one molecule of carbon monoxide is discharged. The complexes are characterized by elemental analysis, by infrared and Mössbauer spectroscopies, and by conductivity measurements; these data are used to predict their possible formulation as nonionic, hexa-co-ordinate iron derivatives of the Fe(CO)3(X)(EPh3)(SnX3) type containing a tin-to-iron metal-metal bond.
The Crystal Structures of Methyl Bromide and Methyl Iodide
Authors: Kawaguchi Takemi , Hijikigawa Masaya , Hayafuji Yoshinori , Ikeda Masashi , Fukushima Reizo , Tomiie Yujiro
Published: July 2006

The crystal structures of methyl bromide and methyl iodide have been determined by the X-ray diffraction method at about −120°C and about −80°C respectively. Both the crystals are isomorphous, with orthorhombic space group D2h16–Pnma. Unit cells containing four molecules have the dimensions: a=4.474(1), b=6.420(2), and c=9.150(1) Å for methyl bromide, and: a=4.597(2), b=6.987(1), and c=10.117(1) Å for methyl iodide. These structures are quite different from that of methyl chloride, which has a symmetry of C2v12–Cmc21. In the three crystals, all the molecules are found on the mirror planes; the difference lies in the mutual orientations of the molecules.
Substituent Effects on Dissociation Constants of 4-and 6-Styryl-2-aminotropones
Authors: Imafuku Kimiaki , Matsumura Hisashi
Published: July 2006

The dissociation constants of two series of 4- and 6-styryl-2-aminotropones were measured spectrophotometrically in 50% aqueous methanol at 20°C. It was found that Hammett’s free energy relationship is applied to the analysis of substituent effects, with ρ=0.59 and 0.40, respectively, and that there is a difference between the electronic effects of the two isomers.
Putranjic Acid. Synthesis and Stereostructure
Authors: Aoyagi Reiko , Moriyama Yoshihiko , Tsuyuki Takahiko , Takahashi Takeyoshi
Published: July 2006

Putranjic acid, isolated from Putranjiva roxburghii has been synthesized from friedelane-2,3-dione and has been shown to be (2S)-2-hydroxy-3,4-seco-friedelan-3-oic acid.
New Syntheses of Maculosidine and Pteleine
Authors: Sekiba Tetsuya
Published: July 2006

2,3-Dihydromaculosidine and 2,3-dihydropteleine were obtained from 2,4-dimethoxy- and 4-methoxy-aniline by condensation with diethyl β-benzyloxyethylmalonate, followed by methylation and subsequent cyclodebenzylation with polyphosphoric acid. The dehydrogenation of the dihydro compounds with 2,3-dichloro-5,6-dicyanobenzoquinone gave maculosidine (4,6,8-trimethoxyfuro[2,3-b]quinoline) and pteleine (4,6-dimethoxyfuro[2,3-b]quinoline) in relatively high yields. Similarly, evolitrine (4,7-dimethoxyfuro[2,3-b]quinoline) and γ-fagarine (4,8-dimethoxyfuro[2,3-b]quinoline) were also prepared.
The Syntheses of Trimethyl dl-(Methoxycarbonylmethyl)-1,2,4-cyclopentanetricarboxylates
Authors: Ito Shosuke , Hirata Yoshimasa
Published: July 2006

The five trimethyl dl-3-methoxycarbonylmethyl-1,2,4-cyclopentanetricarboxylates have been synthesized and their configurations determined. A comparison of their spectral properties with those of the corresponding ester obtained from ikarugamycin indicates that the latter has a cis, trans, trans configuration.
Tubercidin. Its Conversion into 5′-Deoxytubercidin
Authors: Anzai Kentaro , Matsui Masanao
Published: July 2006

Tubercidin (I) was converted into 5′-deoxytubercidin (IV). Mesylation of 2′,3′-O-isopropylidenetubercidin (IX) afforded-2′,3′-O-isopropylidene-5′-O-mesyltubercidin (XVIII), which in situ was treated with benzoyl chloride. The product, N6,N6-dibenzoyl-2′,3′-O-isopropylidene-5′-O-mesyltubercidin (XXII), was converted into N6,N6-dibenzoyl-5′-deoxy-5′-iodo-2′,3′-O-isopropylidenetubercidin (XXIV). Catalytic hydrogenation of XXIV afforded N6-benzoyl-5′-deoxy-2′,3′-O-isopropylidenetubercidin (XXVII). 5′-Deoxytubercidin (IV) was obtained on debenzoylation and deacetonation of XXVII.
The Crystal Structure of Methylene Bichloride, CH2Cl2
Authors: Kawaguchi Takemi , Tanaka Kazuo , Takeuchi Toru , Watanabé Tokunosuké
Published: July 2006

The crystal structure of methylene dichloride has been determined by the X-ray diffraction method at about −120°C. The structure has a symmetry D2h14–Pbcn, and its orthorhombic tetramolecular cell has these dimensions: a=4.249±0.001, b=8.138±0.020, and c=9.492±0.002 Å. The positional parameters of the chlorine and carbon atoms are obtained by a three-dimensional Patterson function, followed by a least-squares refinement including the hydrogen atom. The structure thus obtained is in excellent agreement with the results of lattice-energy calculations. The crystal structure is quite different from that of methylene dibromide (and of methylene diiodide).
The Vacuum Ultraviolet Photolysis of Liquid n-Hexane in the Presence of SF6
Authors: Pitchoozhkin Vadim I , Yamazaki Hideo , Shida Shoji
Published: July 2006

The photolysis of liquid n-hexane has been studied at room temperature and at −78°C by using the resonance lines of Xe and Kr. The main process is hydrogen detachment, giving the same amount of hydrogen and of hexenes; relatively small amounts of the decomposition and dimer products were also formed. Upon the addition of SF6, the yield of the hydrogen detachment decreased strongly with an increase in the concentration of SF6, and then approached a constant value of 0.65 relative to that in pure n-hexane. The total amount of fluorinecontaining products detected in the presence of SF6 was relatively small compared with the amount of the decrease in the hydrogen detachment. As another electron scavenger, C6H13F was also tested; here, the decrease in the hydrogen detachment was quite small.
Luminescence from 2,3-Dimethylbutane Containing Toluene in the Solid Phase at 77°K during γ-Irradiation
Authors: Miyazaki Tetsuo , Saitake Yoshiyuki , Kuri Zen-ichiro , Sakai Shigenori
Published: July 2006

The luminescence from 2,3-dimethylbutane(2,3DMB) containing toluene in the solid phase has been measured at 77°K during γ-irradiation. The emission consists of fluorescence and phosphorescence from toluene. Since the emission becomes zero upon the removal of a γ-ray source, it cannot be due to a post-irradiation effect. It is concluded from the dependency of the intensity on the concentration of toluene that the luminescence is due to an intermolecular energy transfer from 2,3DMB to toluene during γ-irradiation. ESR studies of γ-irradiated 2,3DMB containing toluene have also been undertaken at 77°K in order to obtain some information on the intermolecular energy transfer. The toluene anion is formed in the γ-irradiated 2,3DMB containing toluene. The dimer cation of toluene is formed in the γ-irradiated 2,3DMB containing toluene and an electron scavenger. The luminescence from toluene in the 2,3DMB matrix decreases upon the pre-irradiation of the sample at 77°K. When the pre-irradiated sample is illuminated by the light from a tungsten lamp to photobleach the toluene anion, the luminescence during γ-irradiation is recovered. Since the intensity of the luminescence does not correspond at all to the amount of toluene anions, the luminescence from toluene in the 2,3DMB matrix during γ-irradiation must not be due to a neutralization reaction between a toluene anion and a migrating hole. It is suggested that the migration of energy from the irradiated 2,3DMB to toluene may occur via an excitation transfer reaction.
The Crystal Structure of Di-π-allyl(dihydropentalenylene)dinickel
Authors: Kitano Yukishige , Kashiwagi Michio , Kinoshita Yukio
Published: July 2006

The crystal structure of di-π-allyl(dihydropentalenylene)dinickel, (C8H6)Ni2(C3H5)2, has been determined from three-dimensional single-crystal X-ray photographic data. The crystal of this compound is composed of discrete molecular units in the monoclinic space group P21/a, with two molecules per unit cell with dimensions of a=8.451±0.004, b=12.691±0.005, c=5.976±0.006 Å, and β=108.81±0.05°. The calculated and observed densities are 1.650 and 1.60 g·cm−3 respectively. The structure was deduced from a sharpened Patterson synthesis and was refined by means of the least-squares method to the final R index of 0.121 for 1151 independent non-zero reflections. The molecule has a crystallographic center of symmetry; therefore, two nickel atoms which are complexed in a sandwich fashion between the dihydropentalenylene ring and the π-allyl group take a trans configuration. The distances of the nickel atom from the ring carbons range from 2.03 to 2.27 Å, the closest approach being to the three non-bridging atoms of the five-membered ring. The orientation of the π-allyl groups with respect to the nickel atom is similar to those found in other π-allyl complexes.
Electron-spin-resonance Studies of the Formation and Properties of the Trimeric Vanadyl Dibutylphosphate Complex
Authors: Sato Mitsuo , Takayanagi Teruo , Fujita Yuzaburo , Kwan Takao
Published: July 2006

The extraction of the vanadyl ion (VO2+) from aqueous solutions by di-n-butylphosphoric acid ((C4H9O)2-PO2H) in hexane has been studied by ESR. It has been found that monomeric and trimeric vanadyl di-n-butylphosphate complexes were present in the organic phase, and the equilibrium constant of the reaction involving monomeric and trimeric forms was determined. The ESR spectrum of the trimeric complex, characterized by 22 hf lines with a separation of 39 gauss, was interpreted as resulting from the magnetic exchange interaction between three vanadyl ions. A crystalline vanadyl complex was isolated from the hexane solution and found to be (VOX2)3, where X represents (C4H9O)2PO2−. The properties of the complex were investigated by means of ESR, IR, and the optical absorptions. The mechanism of the extraction of VO2+ by (C4H9O)2PO2H was discussed, and a cyclic model was proposed for the structure of (VOX2)3.
The Bromine Nuclear Quadrupole Resonance of Two Modifications of Indium Tribromide
Authors: Okuda Tsutomu , Furukawa Yoshihiro , Shigemoto Hiroko , Negita Hisao
Published: July 2006

The bromine nuclear quadrupole resonance study of indium tribromide has revealed that there are at least two modifications in its solid state. The high-temperature modification shows the two 81Br resonance lines of 85.985 and 86.205 MHz, with the relative intensity of 1 : 2 at 24.5°C. This modification was stable unless the temperature was lowered to ∼15°C. The low-temperature modification shows one 81Br resonance line, 86.915 MHz, at −196°C and was stable up to ∼30°C. The directions of the z axes of the field gradient were determined by studying the Zeeman effect on each resonance line of the two modifications at room temperature. For the two resonance lines of the high-temperature modification, one and two directions, which had the asymmetry parameters of 0.362 and 0.400 respectively, were observed. The resonance line of the low-temperature modification showed three directions with the asymmetry parameter of 0.387. The crystal structures of the high- and low-temperature modifications were, therefore, concluded to be monoclinic and hexagonal respectively, from the numbers of resonance lines and of the nonequivalent directions of the z axes. The quadrupole coupling constants and asymmetry parameters were analyzed by means of the Townes-Dailey method.
The Applicability of the Theory of R. A. Marcus to the Electron-Transfer Reactions between Polycyclic Aromatic Hydrocarbons and Their Anion Radicals
Authors: Suga Kosaku , Aoyagui Shigeru
Published: July 2006

The rates of electron-transfer from the anthracene-anion radical to anthracene, 1,2-benzanthracene, and pyrene are measured by the electron spin resonance method, with a line-broadening procedure, under experimental conditions in which anion radicals are in a state of free ions or of loose ion pairs. The dependence of the observed rate constants on the standard free energy of reaction, the dielectric constant of the solvent, and the temperature are discussed on the basis of the theory of R. A. Marcus. The free energy of nuclear reorganization, as estimated from the ΔG°-dependence of the rate constants, is much smaller than that predicted theoretically. The observed rate constants are almost independent of the dielectric constants of the solvents; consequently, the reorganization free energy of the solvent must be smaller than the theoretical value. The entropy term contributes to the activation energy to almost the same extent in the solvents with different dielectric constants; this is inconsistent with the theoretical prediction and requires a smaller value for the free energy of solvent reorganization than its theoretical value.
The Infrared Spectra of α-Chlorinated Acetamides
Authors: Mido Yoshiyuki
Published: July 2006

The polarized infrared spectra of α,α,α-trichloroacetamide (TCA) and its deuterated compound (TCA-d) have been measured in the 400–4000 cm−1 region, and the infrared spectra of the series, CClnH3−nCONH2 (n=0–3), and their deuterated compounds have been observed in the solid state. On the basis of the results, the vibrational assignments, the orientation of TCA, the intermolecular hydrogen bonds, and the inductive effect of the introduction of the chlorine atom, and the conformation of TCA have been discussed. It has been proposed that TCA in the solid state has two conformations, which are in linear-chain associations through hydrogen bonds.
Mössbauer Study of the Thermal Decomposition Products of K2FeO4
Authors: Ichida Toshio
Published: July 2006

The thermal decomposition process of a hexavalent iron compound, K2FeO4, was studied by means of the Mössbauer effect. The compound began to decompose in air at about 170°C, and an amorphous product was obtained by the decomposition below 200°C. The product showed a paramagnetic Mössbauer spectrum at 293°K, with an isomer shift and quadrupole splitting of +0.40±0.02 mm/sec and 0.64±0.02 mm/sec respectively; it also showed a magnetically-split six-line spectrum at 4.2°K, with an internal magnetic field of 480±5 kOe. These Mössbauer parameters are characteristic of the Fe3+ state. The intermediate valence states, Fe5+ or Fe4+, were not observed during the decomposition process, and so it was concluded that the Fe6+ ions in K2FeO4 were reduced directly to Fe3+ ions. KFeO2 was formed in air above 250°C, and the temperature dependence of the internal magnetic field showed the Néel temperature of KFeO2 to be very high, 983±10°K.
Light Scattering Studies on the Thermal Denaturation of Bovine Serum Albumin
Authors: Nakagaki Masayuki , Sano Yoh
Published: July 2006

Thermal denaturation of bovine serum albumin (BSA) was studied by means of light scattering and viscosity measurements. The degree of denaturation (wD°) was measured by using HABA, an anionic dye. The values of intrinsic viscosity, weight-average molecular weight and radius of gyration showed no appreciable changes when wD° was within 85 percent, but increased remarkably when wD° exceeded 85 percent. Thus, it has been concluded that the thermal denaturation proceeds in two steps, i.e., intramolecular denaturation in the earlier stage and intermolecular association in the later stage. Analysis of the light-scattering data showed that the aggregated molecule was in a rod-like shape, whose length increased almost linearly with the weight fraction of the aggregated molecule wn, the latter being obtained by analysis of the refractive index increment. On the other hand, the diameter did not change with the degree of denaturation, and its value was about 140 Å, which is almost equal to the largest dimension of the native BSA molecule. It has been concluded that the BSA molecules form aggregates by side-by-side association, whose length is about 2910 Å and diameter about 140 Å.
The Molecular Vibrations and the Rotational Isomerism of (Chloromethyl)methylsilane
Authors: Hayashi Michiro , Ohno Keiichi , Murata Hiromu
Published: July 2006

The infrared spectra of (chloromethyl)methylsilane and its deuterated species have been measured in the gaseous, liquid, and crystalline states. The normal vibration calculation has been carried out using a modified Urey-Bradley force field. It has been concluded that, in the gaseous and liquid states, there exist both the trans and gauche isomers, while only the former persists in the crystalline state. For ClCH2SiD2CH3, a different spectral pattern has sometimes been recorded in the crystalline state before the sample has been annealed enough. It has been concluded that the persisting isomer is in the gauche form in this metastable crystalline state. The trans and gauche isomers have been found, from the temperature dependence of the relative intensities of the spectra, to have nearly the same energy in the liquid state. From the solvent effects of the spectra, the trans isomer has been found to be more polar than the gauche isomer. Therefore, if the C–Cl bond moment is assumed to have the direction of C+–Cl−, the group moment of the C2SiH2 part of the molecule must be in the direction of (Remark: Graphics omitted.) on the bisector of the C–Si–C angle. The vibrational assignments have been worked out taking into account the results of the normal vibration calculations and the reported assignments for chloromethylsilane, dimethylsilane, and ethylmethylsilane.
The Crystal and Molecular Structure of p-Hydroxybenzoic Acid Monohydrate
Authors: Fukuyama Keiichi , Ohkura Kenji , Kashino Setsuo , Haisa Masao
Published: July 2006

The crystal and molecular structure of p-hydroxybenzoic acid monohydrate has been determined by a single crystal X-ray analysis. The crystals are monoclinic, space group P21⁄a, Z=4, with a=17.79, b=6.39, c=6.79 Å, and β=105.6°. The structure was solved by the Patterson and Fourier methods, and refined by the block-diagonal least-squares method to a final R value of 0.086 for 806 non-zero reflections. Pairs of acid molecules form dimers by the hydrogen bonds between carboxyl groups (2.678 Å). The dimers are held together by the hydrogen bonds between phenolic hydroxyl groups and water molecules (2.595 and 2.823 Å); these hydrogen bonds extend around two-fold screw axes to make up layers of the dimers parallel to the (401). The layers are linked by the additional hydrogen bonds between carbonyl oxygens and water molecules (2.823 Å).
Effect of Halogens on the Ionization of Alkali Metals in the Hydrogen Flame Ionization Detector for Ultra-Micro Analysis of Alkali and Alkaline Earth Metals
Authors: Yamada Masaaki , Suzuki Shigetaka , Araki Shun
Published: July 2006

Quantitative treatment of alkali metals in a small hydrogen flame in the presence or absence of halogens was studied. The proportionality of the ion current to the concentration of alkali metals was found to depend on the applied potential of the electrodes. On adding halogens, the concentration of free neutral alkali atoms decreased. Addition of bromine and iodine increased the ionization of alkali metals, while fluorine decreased it slightly. Addition of chlorine increased or decreased the ionization. The thermionic detection mechanism of halogen-containing compounds in TID of gas chromatograph was discussed.
Estimation of the Thermal Yields in the Reaction with Methanes of 80Br Activated by (n, γ) Process
Authors: Saeki Masakatsu , Tachikawa Enzo
Published: July 2006

The Estrup-Wolfgang Kinetic theory has been applied to the results obtained from the reactions of 80Br activated by the (n,γ) process with two methanes, CH4 and CD4. With suitable assumptions, the most probable kinetic parameters, I’s and α’s have been obtained. The thermal yields of the products have been estimated as a function of the m.f. of the Kr moderator as the differences between the yields predicted by the kinetic theory with these kinetic parameters and those experimentally obtained. The thermal CH380Br and CD380Br yields are strongly affected by the m.f. of Kr in such a way that they are not important in the range from zero to around 0.7 m.f. of Kr, but become significant over 0.7 m.f. of Kr. On the other hand, the thermal CH280BrBr and CD280BrBr yields are much less sensitive to the m.f. of Kr and are almost constant at 0.5% over the whole moderator range of Kr.
The Crystal and Molecular Structure of Vitamin B6 Derivatives. I. Pyridoxal Phosphate Hydrate and Pyridoxal Phosphate Methyl Hemiacetal
Authors: Fujiwara Takaji
Published: July 2006

Pyridoxal phosphate hydrate (PLPHYD) was crystallized from an aqueous solution in the form of monoclinic needles; space group P21⁄c with a=10.503, b=13.608, c=7.488 Å, β=93.71° and four molecules in the unit cell. Prism-shaped crystal of pyridoxal phosphate methyl hemiacetal (PLPMHA) was obtained by dissolving the pyridoxal phosphate hydrate crystals into 90% methanol; space group P\barl, with cell dimensions, a=9.42, b=10.61, c=6.20 Å, α=105.6°, β=95.7°, and γ=99.7°, and two molecules per cell. Intensity data were collected on an automated diffractometer for PLPHYD and photographically for PLPMHA. Crystal structures have been determined by the symbolic addition method. Refinements were done by the block-diagonal least-squares procedures, the final R value being 0.093 for PLPHYD and 0.112 for PLPMHA. The free aldehyde group of pyridoxal phosphate interacts with water molecule to form gem-diol in the crystalline state of PLPHYD and the gem-diol group of PLPHYD with methanol to form methyl hemiacetal. One of the two hydrogen atoms on a phosphate group is liberated and protonated to the pyridine ring nitrogen atom, resulting in the zwitterionic structure for both PLPHYD and PLPMHA molecules. All hydrogen bonds in PLPHYD are intermolecular ones, but in PLPMHA there is one OH–O intramolecular hydrogen bond.
The Dimerization of Acrylonitrile to 2-Methyleneglutaronitrile with Metal Halide and Trialkylamine
Authors: Watanabe Yoshihisa , Takeda Makoto
Published: July 2006

Acrylonitrile is dimerized to 2-methyleneglutaronitrile by the binary catalyst system of metal halide and trialkylamine. The catalytic activities of metals are in this order: Co(II)≥Zn(II)>>Fe(II)>Al(III)>>V(III)>Cd(II)>Ti(IV), while that of halogens is I>Br>Cl. Triethylamine is particularly effective for the reaction. The kinetic features are discussed, and a reaction mechanism for the catalyst system of zinc chloride and triethylamine is proposed.
Oxidation of Diphosphine Dioxides, Disulfides and Phosphinothioite and Photolysis of Diphosphine Disulfides. Formation of Phosphinic and Phosphinothioic Anhydrides
Authors: Emoto Tateki , Okazaki Renji , Inamoto Naoki
Published: July 2006

Oxidation of tetraphenyldiphosphine dioxide with an equimolar amount of peroxybenzoic acid (III) gave diphenylphosphinic anhydride in a good yield. Similarly, diphosphine disulfides (II) with 1.5–2.0 mol times of III, gave the corresponding phosphinothioic anhydrides (V), together with the corresponding phosphinic acid and sulfur. II gave V in air in refluxing xylene or o-dichlorobenzene. The yields of V increased with reaction temperature and with reaction time, indicating a homolytic fission of the P(S)–P(S) bond. Reaction of tetraphenyldiphosphine disulfide with sulfur in refluxing o-dichlorobenzene gave bis(diphenylphosphinothioyl) sulfide. Photolysis of II with a low pressure mercury lamp gave phosphinic acid and sulfur under oxygen, and gave phosphine sulfide and O-methyl phosphinothioate in methanol. Phenyl diphenylphosphinothioite gave diphenyl disulfide and diphenylphosphinic acid with silver nitrate.
Optically Active 9,10-Dihydro-9,10-etheno and -ethanoanthracenes. I. Syntheses of Optically Active 1,5-Disubstituted-9,10-dihydro-9,10-etheno and -ethanoanthracenes.
Authors: Tatemitsu Hitoshi , Ogura Fumio , Nakagawa Masazumi
Published: July 2006

1,5-Dimethoxycarbonyl-9,10-dihydro-9,10-ethenoanthracene was synthesized by the reaction of 1,5-dimethoxycarbonylanthracene with dichloroethylene followed by dechlorination with zinc-copper couple. Optical resolution of l,5-dicarboxy-9,10-dihydro-9,10-ethenoanthracene prepared from the dimethyl ester could be achieved by strychnine to give optically pure (−)-dicarboxylic acid and (+)-diacid with an optical purity of 87.3%. Catalytic reduction of (−)-dicarboxylic acid afforded (−)-ethano-dicarboxylic acid. Transformation of the carboxyl groups in various substituent groups to give optically active C2-symmetrical etheno- and ethanoanthracene derivatives belonging to the same series of absolute configuration as that of the starting material is described.
Stereochemical Studies on the Halogenation of Sulfoxides. II. The Bromination of Cyclic Sulfoxides
Authors: Iriuchijima Shinobu , Tsuchihashi Gen-ichi
Published: July 2006

The cyclic sulfoxides, thiane 1-oxide, 4-chlorothiane 1-oxides, and 4-phenylthiane 1-oxides, were brominated with a mixture of bromine and N-bromosuccinimide in the presence of pyridine. The stereoformulas of the products, together with those of the isomers with an inverted sulfoxide configuration, were determined by means of the IR and NMR spectral data and by a comparison of the Rf-values in the tic. As a result, it has been revealed that the bromination reaction gives products in which a bromine atom is introduced stereospecifically at a trans-position to the sulfinyl lone pair, in a manner similar to that of the chlorination reaction reported previously. The same mechanism as in the chlorination is proposed for the main reaction course.
The Structures of the Reoxidation Products of 7,8-Dihydroneopterin
Authors: Sugiura Katsura , Goto Miki
Published: July 2006

On the reduction of d-erythro-neopterin with sodium dithionite, after which it was let stand in neutral pH, three colorless compounds, I, II, and III, and two yellow compounds, I and II, were obtained. On the reduction of d-erythro-neopterin with Fe dust in 25% acetic acid, after which it was let stand at a neutral pH, two yellow compounds, II and III, were obtained. From UV and NMR spectral data as well as from the chemical reactions, the structures for these compounds were identified, Colorless Compound I is 2-amino-4-hydroxy-6-(1′,3′-dihydroxypropyl)pteridine; Colorless Compound II, 2-amino-4-hydroxy-6-(d-erythro-1′,2′,3′-trihydroxypropyl)-pteridine; Colorless Compound III, 2-amino-4-hydroxy-6-(d-threo1′,2′3′-trihydroxypropyl)pteridine; Yellow Compound I, 2-amino-4-hydroxy-6-(1′-oxo-3′-sulfopropyl)-7,8-dihydropteridine; Yellow Compound II, 2-amino-4-hydroxy-6-(1′-oxo-3′-hydroxypropyl)-7,8-dihydropteridine, and Yellow Compound III, 2-amino-4-hydroxy-6-(1′-oxo-2′,3′-dihydroxypropyl)-7,8-dihydropteridine.
Chemical Studies on Tuberactinomycin. V. Structures of Guanidino Amino Acids in Tuberactinomycins
Authors: Wakamiya Tateaki , Shiba Tetsuo , Kaneko Takeo , Sakakibara Hideo , Noda Toshiharu , Take Teruo
Published: July 2006

Tuberactidine (III) is a guanidino amino acid component of an ti tubercular pep tides, tuberactinomycin A and B, while the known guanidino amino acid capreomycidine (V) is involved in tuberactinomycin N and O. The structure of tuberactidine was assigned to be α-(4-hydroxy-2-iminohexahydro-6-pyrimidinyl)glycine and its stereochemistry was also established. During isolation of tuberactidine from an eluate in the column chromatography of tuberactinomycin hydrolyzate, it was converted to Nα-formyltuberactidine dimer (I). In this dimer, structural alternation between a carbinolamine form of cyclol type and an amide lactone form was noticed depending to a pH of the solution. I was hydrolyzed to tuberactidine and viomycidine (IV) with hydrobromic acid. In addition, a plausible pathway for the formation of viocidic acid (VII), one of the artifacts formed during hydrolysis of tuberactinomycin, was proposed.
S
N2 Reactions in Dipolar Aprotic Solvents. III. Chlorine Isotopic Exchange Reactions of Cinnamyl Chlorides and 3-Aryl-2-propynyl Chlorides. Effect of the Unsaturated Group Adjacent to the Reaction Center
Authors: Hayami Jun-ichi , Tanaka Nobuo , Kaji Aritsune
Published: July 2006

Chlorine isotopic exchange reactions of substituted cinnamyl chlorides and 3-aryl-2-propynyl chlorides with tetraethylammonium chloride-36Cl were studied in acetonitrile. In both cases, the electron-donating groups accelerated the reaction. An acceptable linear Hammett relationship was found for the propynyl chlorides. Cinnamyl chlorides gave a linear relationship for the m-substituted compounds superposed by a concaved U-shaped relationship of p-substituted compounds. Both classes of compounds showed 102−3 times of rate enhancement, compared with 2-arylethyl chlorides in the similar isotopic exchange reaction. Features of these SN2 reactions are discussed.
Cyclization Reactions of 1,2-Bis(2-cyanophenyl)propionitriles. II. Synthesis of 5-amino-4,7-dimethoxy-11H-indeno-[1,2-c]isoquinolin-11-one
Authors: Ando Kazuo , Tokoroyama Takashi , Kubota Takashi
Published: July 2006

The structure of 5-amino-4,7-dimethoxy-11H-indeno-[1,2-c]isoquinolin-11-one (2) derived by the degradation of the “red pigment” has been confirmed by synthesis. 5,6-Dihydro-4,7-dimethoxy-11H-indeno[1,2-c]isoquinoline-5,11-dione (3) obtained from 2 was used as a relay compound. This was first converted into 2 by chlorination with phosphorus oxychloride and treatment with ammonia. Subsequently 3 was synthesized from 2-(2-carboxy-3-methoxyphenyl)-4-methoxyindane-1,3-dione (13) via 4,7-dimethoxy-11H-indeno[1,2-c]isocoumarin-11-one (12).
Triisopropoxy Boroxine as a Reducing Agent for Substituted Benzaldehydes
Authors: Iida Hirotada , Kitamura Hironori , Seita Ken , Yamada Kazutoshi
Published: July 2006

Substituted benzaldehydes could be reduced to corresponding benzyl alcohols in fairly good yield at 130 °C, using triisopropoxy boroxine as a reducing agent. The rates of the reduction of benzaldehyde with triisopropoxy boroxine were about ten times as large as those with triisopropyl borate at 110–130 °C.
Stereospecific Reductions of Isoilludin S and M on Alumina Chromatography
Authors: Ichihara Akitami , Matsumoto Takeshi
Published: July 2006

Alumina column chromatography with ethanol as solvent converted planar α-ketols, illudin S and illudin M, to the dihydroxy compounds. The stereospecific reduction was discussed mechanistically as one of the Meerwein-Ponndorf-Verley reduction.
Nonideality of Ammonia Solutions in N,N-Dimethylformamide
Authors: Patnaik Rabindranath , Lloyd William G
Published: July 2006

Solutions of ammonia at 0–40 °C and 0.2–1.2 atm in N,N-dimethylformamide exhibit negative deviations from Raoult’s Law and marked departures from Henry’s Law. This behavior is shown to be consistent with predictions of a simple model for solute-solute hydrogen bonding.
Mechanism of High-energy-induced Luminescence of Solid 2,3-Dimethylbutane Containing Toluene at 77 K
Authors: Miyazaki Tetsuo , Fujitani Yoshiteru , Kuri Zen-ichiro
Published: July 2006

The luminescence from 2,3-dimethylbutane (23DMB) containing a small amount of toluene (To) has been observed in the solid phase at 77 K during γ-irradiation or by ns pulse irradiation with X-rays. The emission spectrum from 23DMB–To (2 mol%) during γ-irradiation at 77 K consists of the fluorescence from the singletexcited toluene and the phosphorescence from the triplet-excited toluene. Both the singlet- and triplet-excited toluenes are formed by the energy transfer from the irradiated 23DMB to toluene. When nitrous oxide or propylene is added to the 23DMB–To mixture, the emission spectrum is changed and becomes very similar to that from the 23DMB–To mixture during illumination with UV lights at 77 K. The spectrum, which disappears upon the addition of nitrous oxide or propylene, consists mainly of phosphorescence. It is concluded that the triplet-excited toluene may be formed by the migration of a hole and an electron. The effects of electron scavengers, such as nitrous oxide and carbon dioxide, or hole scavengers, such as propylene or tetramethylethylene, on the fluorescence have been studied by nsec-pulse irradiation. Since the fluorescence is not appreciably affected by the addition of these scavengers, the singlet-excited toluene may be formed by the excitation transfer.
Mechanisms of Hydrogenation and Hydrogen Exchange of Propylene over the Electron Donor-Acceptor Complexes of Polynaphthoquinones with Potassium
Authors: Iwasawa Yasuhiro , Ogasawara Sadao , Onishi Takaharu , Tamaru Kenzi
Published: July 2006

The mechanisms of the deuterium addition to propylene and the propylene-deuterium exchange reaction over the electron donor-acceptor (EDA) complex of polynaphthoquinone with potassium were investigated by means of mass and microwave spectrometry and gas chromatography in the range from room temperature to 200°C. The hydrogenation as well as the exchange reaction proceeded via the half-hydrogenated state of propylene formed from the adsorbed propylene and the dissociatively-adsorbed deuterium atom on the EDA complex. However, the rate of the exchange reaction decreased upon the Fe addition to the complex, while the hydrogenation was markedly accelerated. The intermediate of the propylene-deuterium exchange reaction was determined to be the half-hydrogenated isopropyl species, whereas the deuterium addition to propylene was suggested to occur via another half-hydrogenated state, the n-propyl species.
The Optically-active Vibration and Elastic Constant of Soda-niter
Authors: Yamamoto Akio , Shiro Yuji , Murata Hiromu
Published: July 2006

A force field which reproduces satisfactorily both the observed vibrational frequencies and the elastic constants has been determined for the sodium nitrate crystal using the short-range interaction model. In addition to the short-range interactions, the long-range interactions of the vibrationally-induced dipoles were also taken into consideration on the basis of the rigid-ion model; those effective charges which explain fairly well the observed TO–LO frequency splittings were obtained. The distribution of the effective charges on each atom was examined; the best set of effective charges has been found to be ZNa=0.87e, ZN=0.17e, and Zo=−0.35e.
Polarographic Studies of Some Metal (II)-Thiocyanate Complexes in Acetonitrile
Authors: Misumi Seizo , Aihara Makoto , Kinoshita Setsuko
Published: July 2006

The formation of thiocyanate complexes of cadmium (II), copper(II), cobalt(II), and iron(II) has been studied in acetonitrile by polarographic, conductometric, and spectrophotometric methods. The values of overall stability constants were found to be; logβ4=19.7 for [Cd(SCN)4]2−, logβ2=7.6 for [Cu(SCN)2]− and logβ4=15.5 for [Co(NCS)4]2−. The reaction between copper(II) species and mercury metal was investigated and the electrode reaction was estimated. Kinetic current for cobalt(II)-thiocyanate complex was observed and the rate constant for the dissociation of the complex was obtained. The rate constant of reduction in the iron(II)-thiocyanate system was determined to be 1.9×10−3 cm/s by cyclic voltammetry.
Effects of Substituents on pKa and τOH Values of Hydroxyaryl-1,3,5-triazines; σP− Values of 1,3,5-Triazinyl Groups.
Authors: Ohto Yukio , Hashida Y\={o}ji , Sekiguchi Shizen , Matsui Kohji
Published: July 2006

Regular relations were found between substituents in the s-triazine nucleus and pKa values, τOH values of o- and p-hydroxyphenyl-s-triazines, and stabilities of chelation of the o-isomers. The substituent constants (σp−) for some s-triazinyl groups were also found.
The Diffusion of Gases at High Pressures. V. The Diffusion of CTH3 in the CO2–Ar System
Authors: Takahashi Shinji
Published: July 2006

The diffusion coefficients of radioactive methane (CTH3) in argon and in mixtures of carbon dioxide with argon(0.719, 0.497, and 0.245 mol fractions of aigon) were measured at the temperatures of 25, 50, and 75°C in the 15∼250 atm pressure range. The measurements were made through a plug of porous bronze in the diffusion cell by using the radioactive tracer technique. The diffusion coefficient-density products, Dρ, for the CTH3–argon system increased slightly with the density in the region below 5 mol/1, and decreased slightly in the region above 5 mol/1. The Dρ for the CTH3–mixture systems decreased slightly with the density over the whole range studied here. The density dependence of Dρ-values at high densities could not be predicted by Enskog-Thorne’s theory.
Studies of the ESR Spectra of Semiquinone Anions of Xanthene Dyes. Variation in the Linewidth of the Phloxine Semiquinone Anion with the Temperature and the Viscosity in Protic Solvents
Authors: Kimura Kazuie , Imamura Masashi
Published: July 2006

The ESR linewidths of semiquinone anions of xanthene dyes in alkaline protic solvents were studied as functions of the temperature and the viscosity. It was found that the linewidths of phloxine semiquinone, the ESR spectra of which show three hyperfine lines due to two equivalent protons, decrease with a decrease in the temperature or an increase in the viscosity of the solvents, and vary unimolecularly. Such a variation can not be explained either by a usual “chemical exchange” process between different states or by intramolecular motion. We propose that the linewidths may be due to the modulation of the hyperfine coupling constants of H atoms; the modulation results from the dissociation and/or distortion of the hydrogen bonds.
A Polarographic Study of the Zinc(II)Ethylenediamine-N,N′diacetate (EDDA) and –Triethylenetetraamine (Trien) Complexes
Authors: Kodama Mutsuo
Published: July 2006

Zinc(II)–EDDA and –Trien complexes produced kinetic waves. By conducting a systematic examination of the nature of the kinetic waves, the reaction mechanisms and the rates of the rate-determining step were determined. The kinetic wave of the zinc(II)–EDDA complex could be ascribed to the reduction of the zinc(II) aquo ion formed upon its slow dissociation at the electrode surface. From a comparison of the observed rate constant with that estimated on the basis of the proposed reaction intermediate, the dissociation of the zinc(II)–EDDA complex was found to proceed through a reaction intermediate in which the leaving EDDA anion is bonded to the zinc(II) ion through the ethylenediamine chelate ring. In the case of the Trien complex, the kinetic wave could be ascirbed to the reduction of the zinc(II)–Trien complex formed upon the slow configurational change of the tetrahedral zinc(II)–Trien complex at the electrode surface.
The Relative cis/trans Reactivity in the Hydrochlorination of 1-Arylpropenes
Authors: Izawa Kunisuke , Okuyama Tadashi , Fueno Takayuki
Published: July 2006

Hydrochlorination of cis- and trans-1 -phenylpropenes and their ring-substituted derivatives (p-CH3O, p-CH3, and p-Cl) has been studied in acetic acid at 16–35°C. 1-Phenylpropene gave predominantly a cis-adduct while the p-CH3O derivative yielded a non-stereospecific product. For the p-CH3O and p-CH3 derivatives, the cis isomer was found to be more reactive than the corresponding trans isomer, while for the p-Cl derivative the opposite relative reactivity was observed. The origins of these cis/trans reactivities have been discussed in terms of the electronic and steric effects on stability of the solvated transition state.
The Addition of 2,4-Dinitrobenzenesulfenyl Chloride to cis- and trans-1-Arylpropenes and Some Other Olefins
Authors: Izawa Kunisuke , Okuyama Tadashi , Fueno Takayuki
Published: July 2006

Kinetic investigations were carried out on the addition of 2,4-dinitrobenzenesulfenyl chloride to the geometrically isomeric pairs of various 1-arylpropenes as well as some related olefins. All the trans isomers of 1-arylpropenes were more reactive than the corresponding cis isomers and the Hammett correlations were observed for respective isomers with ρ=−2.64 (trans) and −2.3 (cis). By contrast, cis-alkenes were more than 10 times as reactive as the corresponding trans isomers. The reactivities of various unsaturated compounds in this reaction were found to be correlated with their ionization potentials constituting two lines accodring to the type of substrates. It was concluded that the greater reactivity of trans-1-arylpropene as compared with the cis isomer is ascribable to the difference in the charge-transfer interaction between the electrophile and a substrate at the transition state. The conclusion is contrasting to the generalization that the relative cis/trans reactivity of alkenes is determined mainly by the Coulombic interaction at the transition state.
Formation and Conformation of Benzoyloxylated Sulfur-containing Heterocycles
Authors: Sugawara Tadashi , Iwamura Hiizu , Oki Michinori
Published: July 2006

Thiane, 1,3-dithiane, and 1,3,5-trithiane were treated with t-butyl peroxybenzoate in the presence of cuprous chloride to yield benzoyloxylated products. Methylenes placed between two sulfur atoms were found to be more reactive than those next to one sulfur atom. Introduction of two benzoyloxy groups into 1,3,5-trithiane afforded cis-2,4-dibenzoyloxy-1,3,5-trithiane only. PMR spectra of benzoyloxylated products at various temperatures indicate that benzoyloxy-axial conformation is overwhelming for all the compounds investigated.
Spin Trapping of Free Radicals Generated from Arylazo p-Tolyl Sulfones
Authors: Kobayashi Michio , Akiyama Eri , Minato Hiroshi , Kito Noboru
Published: July 2006

Arylazo p-tolyl sulfones(I) were thermolyzed or photolyzed in the presence of trapping agents such as α,N-diphenyl nitrone(II), α-phenyl N-t-butyl nitrone(III) and 2-methyl-2-nitrosopropane(X). ESR studies showed that phenyl radical or p-methoxy phenyl radical is produced from the decomposition of I and adds to II or III. The adduct of phenyl radical to II and that of p-methoxyphenyl radiacl to III were synthesized for comparison by separate pathways. The photolysis of phenyl p-tolylazo sulfone(Ia) in the presence of III yielded benzhydryl t-butyl nitroxide, benzoyl t-butyl nitroxide and t-butyl p-toluenesulfonyl nitroxide(XVI) radicals. The photolysis of la in the presence of X gave di-t-butyl nitroxide(XII) and XVI. The photolysis of phenylazotriphenylmethane in the presence of X yielded XII and t-butyl nitroxide radical. The mechanisms of the formation of these radicals are discussed. The formation of arenesulfonyl radicals from the decomposition of I has been proved indirectly (analyses of the products of the combination of nitroxide radicals with arenesulfonyl radicals) and directly (detection of t-butyl p-toluenesulfonyl nitroxide radical.