Journal issue
Volume 55
, Issue 1
Showing 1-50 articles out of 82 articles from the selected issue
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Sadakatsu Nishikawa, Yoshihisa Yamashita, Mitsuo Mashima1982 Volume 55 Issue 1 Pages 1-3
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSUltrasonic absorption and velocity have been measured in aqueous solution of Propyl Cellosolve (ethylene glycol monopropyl ether) in the frequency range of 7.5 to 220 MHz at 25 °C. A single relaxational process has been found and the mechanism has been attributed to the solute-solvent interaction, AB↔A+B. The rate constants obtained are k12=9.6×107 s−1 for the forward and k21=1.3×108 M−1 s−1 for the backward reaction. The effect of the solute on the water structure has been found to act slightly as the water structure promoter and the results have been discussed comparing with those of Butyl Cellosolve solution.View full abstract -
Hideki Masuda, Tooru Taga, Kenji Osaki, Hiroshi Sugimoto, Masayasu Mor ...1982 Volume 55 Issue 1 Pages 4-8
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSThe crystal structure of diaqua(meso-tetraphenylporphinato)cobalt(III) perchlorate, [CoIII(tpp)(H2O)2]ClO4, has been determined by the X-ray method. The compound crystallizes in the monoclinic space group P21/c with four molecules in a unit cell of dimensions, a=13.93(4) Å, b=23.46(2) Å, c=17.35(6) Å, and β=129.4(2)°. The Co(III) ion lies on the mean plane of the porphinato core, and is coordinated by the four porphinato nitrogen atoms and the two water oxygen atoms. The average Co–N distance is 1.964(4) Å, and the average Co–O(water) distance is 1.936(5) Å. The porphyrin plane is significantly ruffled and has an approximate S4-\bar4 symmetry. The perchlorate anion is not bound directly to the cobalt(III) ion, and links the two adjacent [CoIII(tpp)(H2O)2]+ cations by the hydrogen bonds with the aqua ligand oxygen atoms.View full abstract -
Teruhiko Ogata1982 Volume 55 Issue 1 Pages 9-16
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSThe microwave spectra of the 35Cl and 37Cl isotope species of cis- and trans-HFC=CFCl have been studied in the 8–50 GHz region. The rotational constants and the Cl quadrupole coupling constants in MHz are obtained and listed. The quadrupole coupling constants and the structures obtained for cis- and trans-HFC=CFCl are consistent with the results of other haloethylenes.
(Remark: Graphics omitted.)View full abstract -
Akira Fujishima, Yoshikazu Noguchi, Kenichi Honda, Boon H. Loo1982 Volume 55 Issue 1 Pages 17-22
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSPhotoelectrochemical processes at both n- and p-type MoS2 electrodes were studied by rotating ring-disk electrode technique. In comparison with other semiconductor photoelectrodes such as CdS, ZnO, and TiO2, the competitive oxidations of various reducing agents at n-MoS2 electrode were not clearly dependent on their redox potentials. The MoS2 photoanode was particularly stabilized in I− solutions, and this was attributed to the specific adsorption of I− ions on the electrode surface. Two step waves were observed in the photocurrent-potential curves of MoS2 photoanode in I− solutions. The first wave was controlled by the diffusion of I− ions from the bulk solution to the electrode surface, and the second wave at more anodic potential was dependent on the formation of the photogenerated holes.View full abstract -
Masanao Kato1982 Volume 55 Issue 1 Pages 23-27
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSAn analytical equation for the excess Gibbs energies of mixtures was derived on the basis of the non-random two-liquid model, which was applied to the derivation of an analytical equation for excess volumes proposed by the present author. The derived equation involves new adjustable parameters of intermolecular interaction. The validity of the equation was examined for 13 binary mixtures by using the non-randomness factors determined from the excess volume data, and it was shown that the calculated excess Gibbs energies were in good agreement with the observed values. The sequence of the values of the interaction parameters seems to be reasonable.View full abstract -
Makoto Nagashima, Shigehiro Konaka, Masao Kimura1982 Volume 55 Issue 1 Pages 28-32
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSA small-angle electron-diffraction unit (Jpn. J. Appl. Phys., 11, 1199 (1972)) has been improved by enlarging the scattering chamber and installing a new nozzle system and a better counting unit. The intensities of 50 keV electrons scattered by CS2 and CCl4 molecules have been measured with a ≈1% precision in the s-range from 1 to 11.5 Å−1. Theoretical intensities have been calculated for the independent-atom model by taking into account the intramolecular double-scattering effect, and those intensities have been compared with the experimental intensities. The oscillatory feature appearing in the difference function, Δσ(s)=s4(Iexptl–IIAM), of CCl4 has been ascribed mainly to the deformation of the one-electron density in chlorine atoms by chemical binding.View full abstract -
Masami Inoue, Saburo Enomoto1982 Volume 55 Issue 1 Pages 33-35
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSGlycine was obtained by the ammonolysis of trichloroethylene with aqueous ammonia. Various alkalines, such as alkaline metal hydroxides, carbonates, and hydrogencarbonates, accelerated the reaction; the yield of glycine was 40–70% after a 4 h reaction at 180 °C. Our results on the effect of alkalines indicate that ammonolysis proceeded sequentially via the formation of aminoacetonitrile. A good yield of the intermediate compound, aminoacetonitrile, was obtained by heating trichloroethylene at 70 °C with anhydrous ammonia under reaction conditions.View full abstract -
Application of On-line Impedance Measurement Using Fast Fourier Transform to Electrochemical SystemsTetsuya Osaka, Katsuhiko Naoi1982 Volume 55 Issue 1 Pages 36-40
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSAn on-line impedance measuring system based on the fast Fourier transform algorithm was constructed by application of only commercially available interfaces and the FORTRAN language available for an OKITAC System 50/10. A modification of the sampling system is effective for reducing two kinds of errors: the aliasing effect is greatly reduced because of the Nyquist frequency being doubled; the leakage effect is diminished because of the truncation interval being adjusted properly. The above modification enables us to acquire high-accuracy data with quite a small number of averagings processed during one measurement, that is, errors may greatly be reduced and the measurement time to get frequency spectra may be made extremely shorter. The modified impedance measurement using the FFT algorithm is applicable to electrochemical systems proceeding not only at a mercury electrode–solution interface but also at a solid electrode–solution interface.View full abstract -
Yasuhiro Uosaki, Masaru Nakahara, Jiro Osugi1982 Volume 55 Issue 1 Pages 41-44
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSExperimental evaluation was made of rate constants for foward and backward steps of 1,4-cycloaddition between TCNE and α-methylstyrene and of constants for their complex formations in 1,2-dichloroethane, dichloromethane, chloroform, and carbon tetrachloride at a few temperatures around 25 °C. Kirkwood’s dipole model for solvation is applied to analyzing kinetic data obtained. The dipole moment of the transition state is estimated to be 8.5±0.5 Debye, which is larger than either that of the complex (assumed as 1 Debye) or that of the cycloadduct (6±1 Debye). Major cause for the high dipole moment of the transition state is breakdown of the high molecular symmetry of TCNE and minor one is a certain contribution of a zwitterionic structure. The activation entropy for the cycloreversion is negative and in the range of −21 to −48 J K−1 mol−1, corresponding to the high polarity of the transition state.View full abstract -
Takahiro Kurokawa, Kunio Miki, Nobuo Tanaka, Nobutami Kasai1982 Volume 55 Issue 1 Pages 45-47
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSThe molecular structure of [Pd(acac)2(NHEt2)] was determined by means of X-ray diffraction. The crystal belongs to the monoclinic system: a=14.166(1), b=8.209(1), c=14.764(2) Å, β=100.75(1)°, space group P21/n, with Z=4. The structure was solved by the heavy-atom method and refined anisotropically by the least-squares procedure; R=0.067 for 3149 non-zero reflections. The geometry around the Pd atom is square-planar: one of the two (acac) ligands coordinates to the Pd atom by O,O′-chelation, and the other, by σ-bonding of the γ-carbon atom, while the diethylamine occupies the fourth coordination site. A weak intramolecular N–H···O hydrogen bond [2.962(10) Å] is observed.View full abstract -
Kunio Furusawa1982 Volume 55 Issue 1 Pages 48-51
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSPolystyrene latices with a wide range of surface charges were prepared in the absolute absence of conventional emulsifiers by controlling the concentration of potassium peroxodisulfate as an initiator and allowing the polymerization to proceed at a relatively high pH to suppress the Kolthoff reaction; KHCO3 or K2HPO4 buffer was used to keep the polymerizing system near neutral pH. Conductometric titrations with different bases (NaOH and Ba(OH)2) on latices show that the Stern layer charge increases with an increase in the surface charge of latices (σ0) and at about the same rate as σ0 does, leading to a virtually constant diffuse layer charge.View full abstract -
Tohru Koike, Kihei Morinaga1982 Volume 55 Issue 1 Pages 52-54
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSElectronically excited OH(2Σ) is formed both by chemical and thermal excitations in the H2-O2 reaction. The OH(2Σ) emission in the partial equilibrium region of the reaction was measured in 1250–3450 K incident shock waves for a mixture, H2/O2/Ar=2/2/96, at starting pressures, 6–30 Torr. The correlation factor between the emission intensity and the concentration of OH(2Σ) was derived in the temperature region above 2800 K where the thermal excitation of OH(2Σ) is dominant. The factor was utilized to estimate the concentration of chemically excited OH(2Σ) and the rate constant of the reaction O+H+M=OH(2Σ)+M was determined as 1013.92±0.17 exp[−(8.3±1.2) kcal/RT)] (cm6 mol−2 s−1).View full abstract -
Yoshimi Kurimura, Hiroshi Yokota, Kiyotaka Shigehara, Eishun Tsuchida1982 Volume 55 Issue 1 Pages 55-58
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSThe interactions of tris(2,2′-bipyridine)ruthenium(II)([Ru(bpy)3]2+) with some polyanions have been studied by means of cation-exchange resins and the luminescence of [Ru(bpy)3]2+. In an aqueous solution of [Ru(bpy)3]2+ in the presence of sodium poly(p-styrenesulfonate)(PSS), the adsorbability of [Ru(bpy)3]2+ on the cation-exchange resins is strongly suppressed by the binding of [Ru(bpy)3]2+ to the polyanion. The relative luminescence intensity of [Ru(bpy)3]2+ in an aqueous solution is enhanced by the addition of PSS. With the addition of sodium chloride to an [Ru(bpy)3]2+/PSS solution, the interaction is impeded by the shielding of the electrostatic potential in the polymer domains by the counter ions. A cooperative interaction between PSS and [Ru(bpy)3]2+ is postulated with a view to accounting for the results. A chemical application of the interaction is demonstrated.View full abstract -
Akio Furusaki, Takeshi Matsumoto, Kimio Furuhata, Haruo Ogura1982 Volume 55 Issue 1 Pages 59-62
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSThe detailed molecular geometry of pikromycin (C28H47NO8) has been examined by means of X-ray crystal analysis. The crystals are orthorhombic, with four molecules in a unit cell with dimensions of a=11.295, b=25.734, and c=10.509 Å; the space group is P212121. 2259 unique intensity data were collected on a four-circle diffractometer with graphite-monochromated Cu Kα radiation. The structure was solved by the Monte Carlo direct method, using the 30 strongest reflections as the starting set; the 215th random phase set led to the correct solution. The R value reached 0.056 by block-diagonal least-squares refinements. The conformation of the fourteen-membered macrolide ring is considerably different from that of (p-bromobenzoyl) pikromycin in the solid state; e.g., the C=C and C=O conjugated double bonds are cisoid in pikromycin, while they are transoid in the derivative. The molecules are held together through two kinds of intermolecular hydrogen bonds, forming a three-dimensional hydrogen-bonded structure.View full abstract -
Yukio Kosaki, Akira Miyamoto, Yuichi Murakami1982 Volume 55 Issue 1 Pages 63-68
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSSelectivity to N2 in the reaction of NH3 with metal oxides has been markedly increased by the addition of Pt/Al2O3 to the metal oxides, whereas the activity of the metal oxides has not been changed. The metal oxides on their own have oxidized NH3 to NO, NO2, and N2O as well as N2, and furthermore, the selectivities in the reaction with metal oxides have depended markedly on the reaction temperature and inlet concentration of NH3 in the pulse. In the oxidation of NH3 with metal oxide–Pt/Al2O3 mechanical mixtures, N2 has been selectively produced irrespective of the reaction temperature and the inlet concentration of NH3 in the pulse. The activity of the mixtures has been shown, on the other hand, to be the same as that of the metal oxides. All of the experimental data have been explained in terms of the following scheme: In the oxidation of NH3 with metal oxide–Pt/Al2O3 mixtures, NH3 is at first oxidized by metal oxides to form NOx(NO, NO2, and N2O) and N2, then the NOx components is transfered through the gas phase from the metal oxides to Pt particles on Al2O3, and finally the NOx. components react with NH3 on Pt particles to form N2 selectively.View full abstract -
Koichiro Matsuda, Kiwamu Yamaoka1982 Volume 55 Issue 1 Pages 69-76
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSElectric linear dichroism (ELD) of sodium poly(p-styrenesulfonate) (NaPSS) and its 9-aminoacridinium (AA) complex at a mixing ratio of polymer residue-to-dye of 6.14 was studied in aqueous solutions at 20 °C. ELD signals were measured in the electric field strength range 0—ca. 19 kV/cm at the absorption peak wavelengths; they showed a saturating trend at extremely high fields. The average angles between the orientation axis of NaPSS and the transition moments of chromophores were estimated to be 60° at 224.5 nm and 57° at 262 nm for the side chain phenyl group and 50° at 404 nm for the bound AA by using theoretical orientation functions derived for mono- and polydisperse systems. The ELD spectra were measured at fixed field strengths; 275–215 nm for NaPSS and 440–282 nm for NaPSS–AA. The reduced dichroism of NaPSS remained nearly constant throughout the 262 nm band but steadily changed below 224 nm in the 224.5 nm band, indicating that another band exists in the far UV region. The ELD spectrum of the NaPSS–AA complex revealed that the two electronic 1La and 1Lb transition moments of the bound AA are tilted at different angles to the orientation axis of the NaPSS backbone.View full abstract -
Masaharu Oguni, Kazuo Watanabe, Takasuke Matsuo, Hiroshi Suga, Sy&ucir ...1982 Volume 55 Issue 1 Pages 77-84
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSAn adiabatic high-pressure calorimeter was constructed. The calorimeter cell was devised for minimization of the cell mass relative to the volume of the sample chamber. The pressure in the cell was controlled by joining the cell with a transmitting tube to a stabilized high-pressure system. The adiabatic conditions were achieved by temperature control of the transmitting tube as well as of adiabatic shields inside the cryostat. Procedures for the precise pressure control and for the determination of the molar volume and heat capacity with the correction for the mass transfer of pressure-transmitting liquid in a series of measurement were discussed. The apparatus is capable of measurement under constant pressure up to 110 MPa and over the temperature range from 100 to 370 K. The results on liquid 3-methylpentane which was used as the pressure medium proved satisfactory performance of this new-type calorimeter.View full abstract -
Minoru Sumitani, Keitaro Yoshihara1982 Volume 55 Issue 1 Pages 85-89
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSThe rates for direct cis→trans and trans→cis photoisomerizations of stilbene in solution were measured with a newly developed monitor light source for picosecond laser photolysis in the UV region. The rate constant of the trans→cis isomerization is 1.2×1010 s−1 in hexane at 295 K. The fluorescence decay rate constant of the S1 state of trans-stilbene has the same value. Thus, the decay of the S1 state is the rate limiting step and the lifetime of an intermediate perpendicular state (1p) has to be very short. The cis→trans isomerization is very fast and the half life of the excited cis-isomer is less than a few picosecond. These observations strongly indicate that the isomerization reaction proceeds through the potential surface of the singlet excited states.View full abstract -
Taichi Sato, Masahiro Yamamoto1982 Volume 55 Issue 1 Pages 90-94
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSThe extraction of bivalent manganese, cobalt, nickel, and copper from aqueous chloride solutions by longchain alkyl quaternary ammonium carboxylates, prepared by combination of trioctylmethylammonium chloride (R3R′NCl) and carboxylic (octanoic, decanoic, and lauric) acids (R″COOH) in benzene, has been investigated under different conditions. The organic phases are examined by spectrophotometry and infrared spectral measurement. The mechanism of the extraction is discussed on the basis of the results obtained. The extraction efficiency follows the order Cu>Co\simeqNi>Mn, and the extraction process is expressed as M2+(aq)+2Cl−(aq)+3R3R′NR″COO(org)\ ightleftarrows(R3R′N)[M(R″COO)3](org)+2R3R′NCl(org), in which M=Mn, Co, Ni, and Cu. The extracted species of bivalent manganese, cobalt, nickel, and copper exist as the complex (R3R′N)[M(R″COO)3] in an octahedral arrangement.View full abstract -
Shuzo Tokunaga1982 Volume 55 Issue 1 Pages 95-100
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSIn the 20.0-matom dm−3 Cu(II) solution of an initial pH of 4.0, more than 99% of it was removed by addition of calcium silicon alloy in ca. 5 min, and the pH decreased to below 2. The X-ray diffraction pattern of the solid reaction product indicated that the Cu(II) removal took place through reduction to metallic Cu. In the 1.0-matom dm−3 Cu(II) solution, the pH increased from 4.0 to above 9.0 in 30 min, which consequently maintained high removal for a long time. In the constant pH runs, relation of the equivalents of Ca and Si dissolved against that of Cu(II) ions removed showed that not only the Ca moiety but also the Si moiety participated in the reduction of Cu(II) ions. It is desirable to control pH value at 3.0 or higher, or to separate the solid phase from the liquid phase in the first 30–60 min in order to avoid excess dissolution of calcium silicon alloy and to attain high Cu(II) removal. Copper(I) oxide was formed in a solution of pH above ca. 5, which was in contact with the air. In a HNO3 solution, the removal decreased considerably. Sodium nitrate also caused strong interference with the removal which can be prevented by acidifying the solution with HCl to pH ca. 1. When Hg(II) or Cr(VI) ions are present, the Cu(II) removal tends to decrease depending on the amount of calcium silicon alloy added.View full abstract -
Yuzo Tamari, Keizo Hiraki, Yasuharu Nishikawa1982 Volume 55 Issue 1 Pages 101-103
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSThe valence state analysis to determine selenide in mixtures of selenide, elemental selenium, selenite, and selenate compounds was devised by the selective volatilization of selenium as its hydride. As the optimum conditions of the reaction, 6 M (this unit is defined to 1 M=1 mol dm−3 as below.) hydrochloric acid solution was dropped into the mixture and the hydrogen selenide gas generated was absorbed in a solution of sodium hydroxide and hydrogen peroxide. The optimal reaction temperature was found to be 170 °C for 40 min using nitrogen as the carrier gas. Utilizing this method, the fluctuation of the oxidation state of selenium was observed during the storage of zinc selenide samples.View full abstract -
Kikuo Miyokawa, Hidenori Hirashima, Isao Masuda1982 Volume 55 Issue 1 Pages 104-107
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSThe kinetics of the thermal pyridine dissociation reactions of Ni[N-(R-C6H4)salam]2py2, where R=H(1), p-F(2), p-CH3O(3), p-CH3(4), p-Cl(5), and p-Br(6), in solid phase, were analyzed by the isothermal weight-loss measurements. On pyrolysis, these pyridine adducts with an octahedral coordination geometry of Ni(II) liberated pyridine to leave products with the formula Ni[N-(R-C6H4)salam]2. The product obtained from 2 was the diamagnetic monomer, those from 4–6 were paramagnetic polymers with μeff=(3.11–3.30) μB, and that from 3 was paramagnetic with an intermediary moment of μeff=1.45 μB. Reaction mechanisms were different depending on the nature of R: 2 followed the contracting disk equation with E=163 kJ/mol; 3–6 followed the contracting disk equation in the initial period of the reaction (the Ea values were 97 for 3, 134 for 4, 173 for 5, and 172 kJ/mol for 6) and then all except 3 followed Jandar’s equation, in the subsequent period. These Ea values were considered to reflect the bond stability between the central Ni(II) ion and the axial pyridine ligands; these values increased with an increase in the electron-withdrawing property of R. The pyridine dissociation reaction may give rise to the complexes of the monomeric square-planar or to those of the associated, polymeric octahedral structure. Which result occurs does not depend only on the tendency of the central Ni(II) ion to accept, at the apical positions, the coordinate bond from the adjacent molecules.View full abstract -
Takayuki Matsushita, Yoshihisa Hirata, Toshiyuki Shono1982 Volume 55 Issue 1 Pages 108-112
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSThe chlorobis(N-alkylsalicylideneaminato)manganese(III) complexes, MnIII(N-Rsai)2Cl, react with hydrogen chloride to give the corresponding dichloromanganese(IV) complexes, MnIV(N-Rsai)2Cl2, as deep green crystals; R can be n-C3H7, n-C4H9, i-C4H9, n-C6H13, c-C6H11, n-C8H17, n-C12H25, n-C18H37, CH2C6H5, or CH2CH2C6H5. These complexes were characterized by the magnetic susceptibilities, electronic spectra, infrared spectra, and cyclic voltammograms. The complexes (R=n-C12H25 and n-C18H37) are found to be stable toward water in the solid state. A trans, six-coordinate configuration is proposed for these Mn(IV) complexes on the basis of the infrared spectra.View full abstract -
Masanobu Saeki, Mitsuko Onoda1982 Volume 55 Issue 1 Pages 113-116
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSTi5S8 (12R type), which had never been prepared in a pure state, was obtained as a single phase by the chemical-transport method. The conditions for the preparation were determined experimentally. The existence range of the phase was examined for composition and temperature.View full abstract -
Hisafumi Muramatsu, Michio Hirota, Yukio Makino1982 Volume 55 Issue 1 Pages 117-120
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSTo obtain an average tropospheric mixing ratio of dinitrogen oxide over Japan, 90 air samples were collected by aircraft at altitudes up to 7 km from Autumn, 1978, to Spring, 1979, and were analysed by the GC-ECD method. The mean volume-mixing ratio of N2O was 0.310 ppm, and the standard deviation was 0.014 ppm. These results show that the tropospheric N2O is well mixed and that its mixing ratio is higher than 0.30 ppm.View full abstract -
Nobuo Suzuki, Toshinobu Yoshida, Hitoshi Watarai1982 Volume 55 Issue 1 Pages 121-125
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSPartition coefficients (KD) of benzene and 11 chloro derivatives of benzene were determined at 25 °C in two liquid-liquid partition systems: heptane/water and heptane/acetonitrile. Increase of KD with increase of the numbers of Cl atoms in the solute is discussed in terms of surface and cohesive energies. The small difference in KD of the isomers whose Cl atom numbers are 2, 3, or 4 was correlated with a difference in the dipole moment of the solute.View full abstract -
Takashi Ogawa, Mamoru Shimoi, Akira Ouchi1982 Volume 55 Issue 1 Pages 126-129
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSThe crystal and molecular structure of the title complex has been determined by the X-ray diffraction method. The crystal was triclinic, space group P\bar1, a=7.554(1), b=9.001(1), c=5.345(1) Å, α=104.83(1), β=99.20(1), γ=71.02(1)°, Z=1, DX=1.684(1), Dm=1.69(1) Mg m−3, μ(Mo Kα)=2.03 mm−1, and the final R value was 0.030 for 1818 reflections. The molecular arrangement has a center of symmetry and has a slightly distorted octahedral configuration around the central copper(II) atom; each ethylthioacetato ligand forms a chelate ring by coordinating through a sulfur atom and a carboxyl oxygen atom, and two water molecules are also coordinated to the central metal. The solid complex is deep green, different from the diaquabis(alkylthioacetato)copper(II) complexes of the higher alkyl groups (number of C≥3), and it is likely due to the CT band caused by the strong copper–sulfur bond in the complex.View full abstract -
Keiichi Tsukahara, Tatsuo Izumitani, Yasuo Yamamoto1982 Volume 55 Issue 1 Pages 130-135
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSThe kinetics of the reductions of several macrocyclic N4 cobalt(III) complexes by L-ascorbic acid (H2A, have been studied at 25.0 °C, at an ionic strength of 0.10 mol dm−3 (LiClO4), and over the pH range from 1.64 to 3.47. The second-order rate constants in dm3 mol−1 s−1 are 3.4±0.6 (Me6[14]4,11-dieneN4), (4.2±0.2)×10 (Me4[14]tetraeneN4), and (4.2±0.1)×10 (ms-Me6[14]aneN4) for the reactions of [Co(N4)(H2O)2]3+ with HA− ions and (1.1±0.1)×102 (Me6[14]4,11-dieneN4), (1.3±0.1)×103 (Me4[14]tetraeneN4), (5.5±0.1)×10 (ms-Me6[14]aneN4), and (2.9±0.6)×10 ([14]aneN4) for the reactions of [Co(OH)(N4)(H2O)]2+ with HA− ions. The mechanisms of these reactions are discussed, and it is concluded that the lack of saturation of macrocyclic ligands facilitates the electron-transfer reaction between cobalt(III) and ascorbic acid.View full abstract -
Yoshihisa Yamamoto, Hiroko Kudo, Masayasu Mori, Hidetaka Konno1982 Volume 55 Issue 1 Pages 136-139
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSThe title paramagnetic complexes, [Co(5-NOsal)(NH3)4]X2·nH2O (X2=Cl(NO3), Cl2·HCl, and Cl2), all brown in color, have been isolated and characterized by analytical, spectroscopic, and magnetic methods. The effective magnetic moments of the complexes are 1.6–1.8 BM, and the absorption spectra have two peaks, at 387 and 518 nm. In the XPS of the complex, the cobalt 2p peaks have satellites, and the peak of the nitrogen Is could be deconvoluted to that of NH3 nitrogen at 400.2 eV and to that of NO nitrogen at 402.2 eV. This binding energy of the NO nitrogen of the complex is different from that (405.6 eV) of the NO2 nitrogen of the green Paramagnetic tetraammine(5-nitrosalicylato)cobalt(III) complexes, [Co(5-NO2sal)(NH3)4]X2, and establishes the difference between these two series of complexes.View full abstract -
Keiji Akamatsu, Takashi Komorita, Yoichi Shimura1982 Volume 55 Issue 1 Pages 140-148
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSFour glycinato, six L-alaninato, and three (R)-propylenediamine cobalt(III) complexes of a tripodlike quadridentate ligand, N,N-bis(2-aminoethyl)glycinate have been prepared. The geometrical configurations are assigned on the basis of their absorption and circular dichroism spectra, 1H-NMR spectra, the elution behavior in ion-exchanger column chromatography, and the optical resolution of chiral isomers. The absolute configurations of the chiral complexes are tentatively assigned and the characteristics of the tripodlike ligand are discussed.View full abstract -
Kazuo Kashiwabara, Katsuaki Katoh, Tomoji Ohishi, Junnosuke Fujita, Mu ...1982 Volume 55 Issue 1 Pages 149-155
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSA series of the complexes, [Co(CN)4−2n(acac)n(P)2](n−1)+ (acac=acetylacetonate ion, P=P(CH3)x(C6H5)3−x) and several related complexes were prepared. For [Co(acac)2(P)2]+, the P(CH3)3 and P(CH3)(C6H5)2 complexes afford only the cis and the trans isomers, respectively, while the P(CH3)2(C6H5) complex forms both cis and trans isomers. No P(C6H5)3 ligand gave the bis(acac)-type complex. The trans isomers show a strong absorption band in the region of the first absorption band, which is assumed to involve charge transfer transitions between the cobalt(III) ion and a phosphine, while the cis isomers give usual absorption spectra, exhibiting the first d-d absorption band of medium intensity. The methyl and phenyl groups on a phosphorus atom in both cis and trans isomers show triplet signals in the 1H and 13C NMR spectra due to virtual coupling. A trans(P,P) configuration was assigned to all the complexes of [Co(CN)2(acac)(P)2] on the basis of the NMR and electronic spectra. For [Co(CN)4(P)2]−, a trans configuration was assigned from the electronic spectra.View full abstract -
Hideyuki Noguchi, Hiroyoshi Nakamura, Masatoshi Nagamatsu, Masaki Yosh ...1982 Volume 55 Issue 1 Pages 156-158
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSProtonated amino acids were extracted with crown ether and Metanil Yellow anion into 1,2-dichloroethane. The overall extraction constants (Kex) for the 1:1:1 complex, AHLIn, of 18-crown-6 (L) with protonated amino acid (AH+), and the Metanil Yellow anion (In−) between 1,2-dichloroethane and water have been determined at 25.0 °C. The values of the extraction constants (logKex) were found to be 5.2, 6.2, 6.4, 6.3, 5.5, 6.2, and 5.5 for L-α-alanine, L-valine, L-leucine, L-phenylalanine, β-alanine, L-lysine, and aspartic acid respectively at 25.0 °C. The dependence of the varieties of crown ether on the extractability of L-leucine has been investigated. The highest extractability was obtained when water-soluble crown ether was used.View full abstract -
Michinori Oki, Giichi Izumi, Gaku Yamamoto, Nobuo Nakamura1982 Volume 55 Issue 1 Pages 159-166
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSCompounds which carry a methoxyl or a chloro group in 1-position and a substituted carbonylmethyl group in 9-position of the triptycene system have been prepared to examine populations of rotamers by 1H NMR spectra. The methoxy compounds favored the ±sc conformations, whereas the ap conformations were relatively favored in the chloro compounds. The results indicate that there are attractive interactions between the carbonyls and a methoxyl or a chloro group and are discussed from the electron-accepting ability of the carbonyl group and the electron-donating ability of the methoxyl and the chloro groups. An aldehyde group was apparently less able to interact with electron-donors than a ketone. This apparent anomaly was discussed from the intramolecular dipolar interactions.View full abstract -
Masahito Segi, Masaki Takebe, Shinji Masuda, Tadashi Nakajima, Sohei S ...1982 Volume 55 Issue 1 Pages 167-170
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSThe Friedel-Crafts alkylation of benzene with (+)-2-methyloxetane in the presence of Lewis acids (AlCl3, SnCl4, and TiCl4) gave 3-phenyl-1-butanol with 20–60% inversion of configuration at the reaction center and a mixture of 4-chloro-2-butanol and 3-chloro-1-butanol in optically active form as the by-products. These by products were formed by the attack of the chlorine atom in Lewis acid. The stereochemical course of the reaction to 3-chloro-1-butanol varied with the kind of catalyst, i.e., inversion with AlCl3 or TiCl4 and retention with SnCl4. The addition of nitromethane to the reaction system promoted the retentive ring-opening to 3-chloro-1-butanol.View full abstract -
Tadatoshi Ota, Seizo Masuda, Hitoshi Tanaka, Masaru Kido1982 Volume 55 Issue 1 Pages 171-173
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSThe thermal oligomerization of 3-methyl-3-buten-2-one oxime leads to crystalline nitrone derivatives, 8-hydroxy-1,4,5,7-tetramethyl-6,8-diazabicyclo[3.2.1]oct-6-ene 6-oxide. Its crystal structure has been determined by X-ray diffraction. The space group is P21/n with a=9.459(3), b=10.335(3), c=11.352(4) Å, β=105.50(2)°, and Z=4.View full abstract -
Kenji Okawa, Kiichiro Nakajima, Takumi Tanaka, Masahiro Neya1982 Volume 55 Issue 1 Pages 174-176
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSThe 2-aziridinecarboxylic acid residue in peptides was isomerized with NaI in an acetone solution into the corresponding dehydroalanine or dehydro-2-aminobutyric acid derivatives, but not into the corresponding 2-oxazoline derivatives.View full abstract -
Osamu Itoh, Naoki Iwakoshi, Toshihide Saitoh, Hiroaki Katano, Yoshiki ...1982 Volume 55 Issue 1 Pages 177-181
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSRegio- and stereochemical studies of the solvolyses of various kinds of 2,4-pentanediol derivatives, including 2-acetoxy-4-tosylates, cyclic orthoformates and orthoacetates, have been done and the previously proposed mechanism has been partially revised. The reactions of the proposed intermediate acetoxonium ions with carbanions and with a hydride ion have also been studied.View full abstract -
Hiroyuki Higuchi, Tetsuo Otsubo, Fumio Ogura, Hachiro Yamaguchi, Yoshi ...1982 Volume 55 Issue 1 Pages 182-187
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSPyrolyses of a series of selenides and diselenides were studied. Selenides and diselenides bound with an active methylene group like benzyl gave a variety of substituted bibenzyls and related ethane derivatives in high yields. Other diselenides were easily caused to cleave to give various aromatic and aliphatic olefins in good yields together with elemental selenium. Lepidopterene, [2.2]paracyclophane, and benzocyclobutene were prepared by thermal cleavage of their corresponding phenylselenomethyl-substituted compounds as an application of the pyrolysis concerned.View full abstract -
Yoshihito Watanabe, Shigeru Oae, Takashi Iyanagi1982 Volume 55 Issue 1 Pages 188-195
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSOxygenations of thioanisole derivatives have been shown to be promoted with phenobarbital induced rabbit liver microsomes. In order to understand the mechanistic details of the oxygenations, a kinetic study on the S-oxygenation promoted by a reconstituted system with purified cytochrome P-450 has been carried out. Log(Vmax) were correlated with the one electron oxidation potentials of the sulfides (Ep). The oxygenation is considered to proceed via one electron transfer from the sulfides to the iron-bound “oxenoid” intermediate of the enzyme. A similar O-demethylation of anisoles has been investigated. In the oxidative O-demethylation of p-methoxy-d3-anisole with rabbit liver microsomes, an intramolecular kinetic isotope effect of 3.4 was observed. Meanwhile, a large isotope effect of 5.1 was observed in the competitive O-demethylation of p-dimethoxybenzene and p-di(methoxy-d3) benzene. In order to clarify the oxidation pathway of O-demethylation with the enzymatic system of cytochrome P-450, the rates of the O-demethylation of p-substituted anisoles have been measured. Unlike the enzymatic oxygenation of sulfides, there was no correlation between the rates of O-demethylation reaction and one electron oxidation potentials of anisoles. These observations suggest that the O-demethylation of anisoles proceeds via the initial hydrogen abstraction with the iron-bound “oxenoid” intermediate of the cytochrome P-450.View full abstract -
Shinro Yasui, Kaoru Nakamura, Atsuyoshi Ohno, Shinzaburo Oka1982 Volume 55 Issue 1 Pages 196-199
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSReductions of thiobenzophenone derivatives with a model compound of NAD(P)H, 1-benzyl-1,4-dihydronicotinamide (BNAH) or N-(α-methylbenzyl)-1-propyl-2,4-dimethyl-1,4-dihydronicotinamide (Me2PNPH), in a solvent containing an O-deuterated alcohol afforded products partially deuterated at their methine positions. The deuterium content depends both on the character of substituents in the substrate and on the polarity of solvent. In contrast, no incorporation of deuterium into the product was observed in the reduction of thiopivalophenone with BNAH or Me2PNPH under the same conditions. These results can be accounted for in terms of an electron transfer followed by a proton transfer from the model to substrate. This is the first and direct evidence for the ion radical-pair intermediacy for reductions by model compounds of NAD(P)H.View full abstract -
Noritaka Abe, Tarozaemon Nishiwaki, Toshimasa Omori, Emiko Harada1982 Volume 55 Issue 1 Pages 200-204
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESS2,3-Dibenzoylpyrrolo[2,1-b]benzothiazole (2) and 6,7-dibenzoylpyrrolo[2,1-b]thiazoles (5a–b) have been synthesized by utilizing the cycloaddition reactions of imidazo[2,1-b]benzothiazole and imidazo[2,1-b]thiazoles, respectively, with dibenzoylacetylene followed by the elimination of a nitrile from each of the cycloadducts. Heteroannelations to 2 and 5 have been achieved by their reactions with hydrazine, aminoacetonitrile, ethyl glycinate, and phosphorus pentasulfide. The annelations by the second and third reagents proceed fairly regioselectively. Facile dimerizations of thieno[3′,4′:3,4]pyrrolo[2,1-b]benzothiazole and thieno[3′,4′:3,4]pyrrolo[2,1-b]thiazoles to be produced by the reactions with the last reagent are also described.View full abstract -
Masaaki Ueki, Toshiyuki Inazu1982 Volume 55 Issue 1 Pages 204-207
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSThe use of the dimethylphosphinothioyl(Mpt) group for the protection of the hydroxyl function in the tyrosine side-chain was studied. N,O-Bis(Mpt)tyrosine was obtained directly by a Schotten-Baumann-type reaction of Mpt–Cl with tyrosine. The O-Mpt group was stable under acidic conditions, and it could be removed easily by alkaline hydrolysis or ester-exchange reaction. The usefulness of this new protecting group for the peptide synthesis was shown in the solid-phase synthesis of [D-Ala2, L-Leu5]-enkephalin(H–L-Tyr–D-Ala–Gly–L-Phe–L-Leu–OH) and its N-allyl derivative.View full abstract -
Yoshinobu Inouye, Satoru Inomata, Yasumasa Ishihara, Hiroshi Kakisawa1982 Volume 55 Issue 1 Pages 208-211
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSThe Claisen rearrangement of 1-methyl-2-[(3-methylphenoxy)methyl]cyclopentene in N,N-dimethylformamide gave 5-methyl-2-(1-methyl-2-methylenecyclopentyl)phenol(5) via its trimethylsilyl ether. The methylation of 5, followed by a Simmons-Smith reaction and by the catalytic hydrogenolysis, afforded 3-hydroxycuparene.View full abstract -
Shinnichiro Suzuki, Jun Kino, Akitsugu Nakahara1982 Volume 55 Issue 1 Pages 212-217
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSThe horseshoe crab Co(II) hemocyanins were prepared by dialyses of Tachypleus tridentatus, Tachypleus gigas, Limulus polyphemus, and Carcinoscorpius rotundicauda apohemocyanins against Tris–HCl buffer (pH 8.0) containing Co(II) ion. The amounts of Co(II) introduced into apohemocyanins reached almost 100% of the total sites for copper ion in native hemocyanins. However, all the four Co(II) hemocyanins did not take up oxygen molecule at all. The extremely similar spectral data for the four species revealed that there is no essential difference in the structure of the respective active sites. Both the two Co(II) ions at an active site are in the high spin state and in an distorted tetrahedral geometry, having no such ligating groups as cysteinyl or methionyl sulfur, but at least three nitrogenous ligands, probably histidine imidazoles. On the basis of these data, the environment of active site in native horseshoe crab hemocyanin is discussed.View full abstract -
Mitsuo Sekine, Masashi Nakajima, Tsujiaki Hata1982 Volume 55 Issue 1 Pages 218-223
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSα-Lithiated diethyl α-(trimethylsilyloxy)benzylphosphonate underwent facile acylation with various acylating agents to afford the corresponding α-acylated products in good yields. On treatment of the α-acylated products with 1 M NaOH–EtOH (1:1, v/v) the P–C bond was cleaved with elimination of diethyl phosphate to give α-hydroxy ketones predominantly. On the other hand, when diethyl α-acyl-α-ethoxybenzylphosphonates were treated under the same conditions, they were rather stable and recovered. However, the prolonged alkaline treatment or the use of 4 M NaOH–EtOH (1:1, v/v) resulted in the C–C bond cleavage giving carboxylic acids and diethyl α-ethoxybenzylphosphonate in quantitative yields, respectively. The mechanisms of the above two reactions were proposed and discussed in connection with the Perkow reaction and related reactions.View full abstract -
Mitsuo Sekine, Masashi Nakajima, Akiko Kume, Akio Hashizume, Tsujiaki ...1982 Volume 55 Issue 1 Pages 224-238
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSCarbonyl addition compounds of diethyl trimethylsilyl phosphite (DTMSP) with aldehydes were converted, by treatment with lithium diisopropylamide (LDA) followed by the successive alkylation and alkaline hydrolysis, to carbonyl derivatives involving aldehydes, unsymmetrical ketones, β,γ-unsaturated ketones, and carboxylic acids. β-Substituted carboxylic esters and γ-substituted lactones were prepared by use of the carbonyl addition compounds of DTMSP with α,β-unsaturated aldehydes.View full abstract -
Mitsuo Sekine, Hiroyuki Mori, Tsujiaki Hata1982 Volume 55 Issue 1 Pages 239-242
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSNucleoside ethoxycarbonylphosphonates were prepared by condensation of appropriately protected nucleosides with ethoxycarbonylphosphonic acid. They were easily converted by treatment with 1 M NaOH followed by trimethylsilylation to highly reactive bis(trimethylsilyl) nucleoside phosphite intermediates which were allowed in situ to react with water, diphenyl disulfide, 2,2′-dipyridyl disulfide, and aldehydes to afford the corresponding nucleoside phosphonates, nucleoside S-phenyl phosphorothioates, nucleoside phosphates, and nucleoside α-hydroxy phosphonates in good yields, respectively. The nucleoside phosphonates were further converted to nucleosides under mild acidic conditions. Thus, the ethoxycarbonyl group proved to serve as a versatile protecting group for not only H–P(O) but also HO–P(O) and hydroxyl groups of sugars.View full abstract -
Renji Okazaki, Kazuhiko Sunagawa, Mitsuharu Kotera, Kyung-Tae Kang, Na ...1982 Volume 55 Issue 1 Pages 243-246
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSPhotochemical reactions of naphtho[1,2-c][1,2]dithiole-3-thione (7), naphtho[2,1-c][1,2]dithiole-1-thione (10), and naphtho[2,3-c][1,2]dithiole-3-thione (16) with cyclohexene and 2,3-dimethyl-2-butene afford the corresponding naphthothioquinone methides. The thioquinone methide from 7 exists only as a monomeric form and is the first isolable o-thioquinone methide, while that from 16 exists as a dimer of [4+4] type in the solid state although the chemical behavior suggests the presence of a monomeric form in solution to a very minor extent. In the case of the thioquinone methide from 10, there exists an equilibrium between a monomer and a dimer of [4+2] type. Some cycloadditions of these thioquinone methides are also described.View full abstract -
Sizuaki Murata, Masaaki Suzuki, Ryoji Noyori1982 Volume 55 Issue 1 Pages 247-254
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSTrimethylsilyl trifluoromethanesulfonate promotes ring opening reactions of oxirane derivatives. The reaction course is highly affected by the structures and substitution pattern of the substrates. Tetra-, tri-, and 2,2-disubstituted oxiranes and simple cycloalkene oxides are converted to the corresponding allylic alcohol trimethylsilyl ethers. The overall transformation is interpreted in terms of trans addition of the silyl trifluoromethanesulfonate to the oxirane ring followed by base-promoted anti elimination of a trifluoromethanesulfonic acid element. 2,3-Dialkyl- or monoalkyloxiranes isomerize to the corresponding ketones and aldehydes, respectively. (Z)-Cyclooctene oxide undergoes the transannular reaction to give endo-cis-2-trimethylsiloxybicyclo[3.3.0]octane. The reaction of 6-methyl-5-hepten-2-one oxide produces 2,2,6-trimethyl-3-trimethylsiloxy-3,4-dihydro-2H-pyran. 1,2-Methyl migration takes place in the reaction of (E)-3α-t-butyldimethylsiloxy-5α-pregnene 17α,20-oxide to afford 3α-t-butyldimethylsiloxy-17β-methyl-17α-[1-(trimethylsiloxy)ethyl]-18-nor-5α-androst-13(14)-ene. α-Pinene oxide gives trans-carveol trimethylsilyl ether.View full abstract -
Kohei Tamao, Jun-ichi Yoshida, Munetaka Akita, Yoshihiro Sugihara, Tak ...1982 Volume 55 Issue 1 Pages 255-260
Published: 1982
Released: June 27, 2006
JOURNALS FREE ACCESSDescribed herein are several representative examples of cleavage reactions of otherwise hardly accessible organopentafluorosilicates which are obtainable via the Diels-Alder reaction, ene reaction, and the Friedel-Crafts reaction of vinyl-, ethynyl-, or allyl-trichlorosilanes. The Diels-Alder reaction between vinyltrichlorosilane and o-xylylene generated in situ by debromination of α,α′-dibromo-o-xylene afforded (1,2,3,4-tetrahydro-2-naphthyl)trichlorosilane which was converted to the corresponding silicate. The silicate reacted with NBS and MCPBA to give the respective bromide and alcohol. The Diels-Alder reaction between ethynyltrichlorosilane and methyl coumalate gave a mixture of meta and para isomers of methyl (trichlorosilyl)benzoate in the ratio of 55/45, the silicate of which reacted with NBS to give two positional isomers of methyl bromobenzoate. The electronic effect of the methoxycarbonyl group on the Si–C bond cleavage was small. The silicate derived from 4-octenyltrichlorosilane which was obtained by the ene reaction between vinyltrichlorosilane and 1-hexene afforded, upon treatment with NBS, 4-octenyl bromide in the ratio of E⁄Z=83⁄17. The sterically crowded neophylsilicate obtainable via the Friedel-Crafts reaction of 2-methyl-1-propenyltrichlorosilane with benzene underwent the cleavage reaction with NBS in methanol. Neophyl bromide was formed with CuBr2 in a low yield, no product being formed arising from rearrangement of the neophyl radical.View full abstract