Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
Volume 54 , Issue 7
Showing 1-50 articles out of 70 articles from the selected issue
  • Chikara Hongo, Shigeki Yamada, Ichiro Chibata
    1981 Volume 54 Issue 7 Pages 1905-1910
    Published: 1981
    Released: June 02, 2006
    JOURNALS FREE ACCESS
    In the optical resolution process of DL-serine m-xylene-4-sulfonate dihydrate by the preferential crystallization procedure, the stability of the supersaturation state of the unseeded isomer was investigated in connection with the cooling conditions. The experiment was initiated with the model solution and was then extended to the actual resolution process. The metastable region of the unseeded isomer on a two-dimensional diagram with the supersaturation degree and cooling time could be divided into the first and the second metastable regions. The limits of the first and the second metastable regions were expressed by a supersaturation degree and by an area on the diagram respectively. Both limiting values were constant, independent of cooling speed and the lowest arrival temperature, if the conditions for the crystallizer, the initial concentration of the DL-form, the amount of the seed crystals, and the degree of stirring were fixed.
  • Chikara Hongo, Shigeki Yamada, Ichiro Chibata
    1981 Volume 54 Issue 7 Pages 1911-1913
    Published: 1981
    Released: June 02, 2006
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    In the optical resolution of DL-serine m-xylene-4-sulfonate dihydrate by the preferential crystallization procedure, the prediction of the resolution process was studied. The solution saturated with the DL-form at 20 °C was cooled under a programmed cooling pattern and was seeded with the L-isomer. The decrease in the concentration of the L-isomer during the process was predicted by a conventional calculation method. Then, the waiting time for the spontaneous crystallization of the D-isomer was predicted by using the limiting values of the first and the second metastable regions, which were discussed in a previous report. As a result, a good agreement was obtained between the predicted results and the experimental results.
  • Hiroshi Kawabe
    1981 Volume 54 Issue 7 Pages 1914-1919
    Published: 1981
    Released: June 02, 2006
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    Procedures to evaluate rigorously the rate constants in the animations of chloromethylated polystyrene which are accompanied by acceleration and deceleration have been developed. The calculated fractional conversions in the reaction of chloromethylated polystyrene with 2-amino-1-butanol in dioxane, accompanied by acceleration, and the reaction with triethylamine in dimethyl sulfoxide, accompanied by deceleration, are proved to be in good agreement with the observed ones. The activation parameters of these reactions, in addition to the kinetic data in N,N-dimethylformamide, support the conclusion that the acceleration and the deceleration are due to the formation of the hydrogen bond and to the electrostatic effect from the neighboring groups in the respective transition states.
  • Tsutomu Okuda, Morio Hiura, Hisao Negita
    1981 Volume 54 Issue 7 Pages 1920-1922
    Published: 1981
    Released: June 02, 2006
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    Zeeman effects of 63Cu and 81Br NQR spectra of bis(triphenylphosphine)copper(I) bromide, CuBr(PPh3)2, have been studied at room temperature. The asymmetry parameters and the quadrupole coupling constants (e2Qqh) have been found to be 0.113 and 64.58 MHz for 63Cu and 0.518 and 105.91 MHz for 81Br. The large asymmetry parameter of the 81Br NQR line is caused by the π-bonding character of the copper-bromine bond. The bonding scheme between the copper and bromine atoms is discussed on the basis of the obtained directions of the electric field gradient axes.
  • Hiroaki Ohya-Nishiguchi, Masahiro Khono, Kiyoko Yamamoto
    1981 Volume 54 Issue 7 Pages 1923-1927
    Published: 1981
    Released: June 02, 2006
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    The ESR spectra of the paramagnetic species generated electrochemically from α,β,γ,δ-tetraphenylporphinatocobalt(II), [CoII(tpp)], have been observed under the conditions of low-temperature, in chlorinated or nonchlorinated solvents, and in the presence of various supporting electrolytes. From the ESR parameters obtained, three different paramagnetic species, [CoIII(tpp)]2+(X)2, [CoIII(tpp)]2+(Y)2, and [CoIII(tpp)]2+(X)(Y), have been confirmed. The ESR spectrum of thermally and optically accessible paramagnetic species in the solution of chlorotetraphenylporphinatocobalt(III) has been reproduced by the pertinent combination of solvent and supporting electrolyte, and well interpreted by assuming the formation of [CoIII(tpp)]2+(Cl)2. Arguing from a correlation between the hfcc of cobalt and nitrogen nuclei in this species, a spin-polarization mechanism is proposed to interpret the cobalt hfcc.
  • Hisao Igarashi, Koji Kaya
    1981 Volume 54 Issue 7 Pages 1928-1932
    Published: 1981
    Released: June 02, 2006
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    Collision induced intersystem crossing (slow fluorescence quenching and phosphorescence induction) from selected vibronic levels of pyrazine in S1(nπ*, B3u) was investigated. It was found that slow fluorescence quenching rate at the zero point level exceeds the hard sphere collision rate several times and rapidly approaches it as the excitation energy is increased. On the other hand, phosphorescence induction rate was found to be nearly equal to the collision rate and to have little excitation energy dependence. These differences were discussed on the basis of the collision induced relaxation mechanisms.
  • Masako Yudasaka, Tadashi Sugawara, Hiizu Iwamura, Tsunetake Fujiyama
    1981 Volume 54 Issue 7 Pages 1933-1938
    Published: 1981
    Released: June 02, 2006
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    The chloride-water mixture and the chloride-water-acetone mixtures were studied by measuring the 35Cl NMR spectra. From the line-width analyses, it has been concluded that the line-widths of the chloride solutions are affected only by the nearest neighbours of the chloride ions, which makes it possible to study the interaction between the chloride ion and the solvent molecules microscopically. The problem concerning the ion pair formation in solutions was discussed. It has been shown that the observation of the concentration dependence of line-widths can be very powerful method for the detection of contact ion pairs formed in the solutions.
  • Nobuyuki Ito, Masako Yudasaka, Tsunetake Fujiyama
    1981 Volume 54 Issue 7 Pages 1939-1942
    Published: 1981
    Released: June 02, 2006
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    The structure of the 12-hydroxyoctadecanoic acid-benzene gel was studied by the use of the light scattering spectrometer. The scattering angular dependence of the scattering intensity and the time correlation function of the electric field were measured. It was found that the coarse mesh network and the fine mesh network coexist in this gel. The former was detected by the intensity measurement, while the latter was detected by intensity-fluctuation spectroscopy. The usefulness of the light scattering technique was emphasized.
  • Keiji Itabashi, Tetsuo Takaishi, Tatsuo Ohgushi
    1981 Volume 54 Issue 7 Pages 1943-1945
    Published: 1981
    Released: June 02, 2006
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    The encapsulation of krypton is realized with zeolite A, having compositions (K12−2xMxII-A with 1.11≤x≤3.78, at temperatures lower than 300 °C and a pressure of 3.7×106 Pa. This encapsulation condition is much milder than the usual one, 350 °C and 4.2×108 Pa, which is adopted in industry. Such lowerings of the encapsulation temperature and pressure are caused by bivalent cations introduced through ion-exchanges. The result is an experimental evidence to the existence of the ion-loosening effect proposed in preceding papers.
  • Kyuya Yakushi, Yoshiyuki Sato, Isao Ikemoto, Haruo Kuroda
    1981 Volume 54 Issue 7 Pages 1946-1949
    Published: 1981
    Released: June 02, 2006
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    The electronic absorption spectra of 2,6-bis(dicyanomethylene)-2,6-dihydronaphthalene (11,11,12,12-tetracyano-2,6-naphthoquinodimethan; TNAP) and its anion radical (TNAP) were studied. The absorption bands of the solution spectra of TNAP0 and TNAP were successfully assigned to the electronic transitions which were calculated by the use of molecular orbital method. The polarized absorption and reflection spectra were measured on the single crystals of Na·TNAP and (methyltriphenylphosphonium)(TNAP)2 [(MTPP)(TNAP)2]. The low-lying electronic excitations of these complexes are quite similar to those of the corresponding tetracyano-quinodimethan (TCNQ) salts.
  • Ryuichi Nakamura, Shuichi Nakai, Kazuo Sugiyama, Etsuro Echigoya
    1981 Volume 54 Issue 7 Pages 1950-1953
    Published: 1981
    Released: June 02, 2006
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    TiO2-supported noble metal catalysts, such as Pt–, Pd–, and Rh–TiO2, are much more active for the NO–CO reaction in the presence or absence of H2O, H2, and O2 than the corresponding Al2O3– or other supported catalysts. They are effective even in an oxidative gas composition range for the NO–CO–(H2O)–H2–O2 reaction, producing no NH3 in the NO–CO–H2O reaction. Comparison of the catalytic activity and properties of Pt–TiO2 with those of other supported catalysts suggests that the higher activity of the TiO2-supported catalysts could be attributed to their ability to activate NO molecules by the dissociative adsorption at lower temperatures.
  • Kazuaki Harata, Kaneto Uekama, Masaki Otagiri, Fumitoshi Hirayama, His ...
    1981 Volume 54 Issue 7 Pages 1954-1959
    Published: 1981
    Released: June 02, 2006
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    The crystal structure of the α-cyclodextrin–benzaldehyde (1:1) complex hexahydrate, C36H60O30·C7H6O·6H2O, was determined by the X-ray method. The crystal is monoclinic, the space group being P21 with Z=2. The cell dimensions are a=7.932(1), b=13.500(1), c=24.704(2) Å, and β=90.85(1)°. The structure was solved by means of a Patterson map and a trial-and-error method combined with the rigid-body least-squares technique. Refinement was carried out by the block-diagonal least-squares method to the final R-value of 0.057 for 4565 reflections. α-Cyclodextrin molecules are stacked along the a axis in a head-to-tail fashion to form a channel-type structure. The α-cyclodextrin ring is tilted by an angle of 11.5° against the channel axis. Adjacent α-cyclodextrin molecules along the channel are linked by hydrogen bonds between the primary hydroxyl groups and the secondary hydroxyl groups, and O(2)···water···O(6) hydrogen-bond bridges. The guest benz-aldehyde molecules are aligned inside the α-cyclodextrin column. The benzene ring is inserted into the α-cyclodextrin ring from the secondary hydroxyl side, while the carbonyl group is in the van der Waals contact with the primary hydroxyl side of the next α-cyclodextrin. The guest plane is nearly parallel to the channel axis, making an angle of 71.2° against the plane through six glycosidic oxygen atoms. Spaces between α-cyclodextrin columns are filled with water molecules. Many hydrogen bonds are observed among hydroxyl groups of α-cyclodextrin and water molecules, forming a hydrogen-bond network in the crystal.
  • Byong-Tae Chang
    1981 Volume 54 Issue 7 Pages 1960-1963
    Published: 1981
    Released: June 02, 2006
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    A reasonable method for determination of thermodynamic properties of alumina hydrates from their solubility data in alkaline pH range was presented and applied to the solubility data of gibbsite in NaOH solutions with success. When log(Ksaw), where Ks=mHmAl and aw is the activity of water, was plotted against a Debye-Hiickel function of the ionic strength I, I1⁄2⁄(1+BtalI1⁄2), a linear relationship to moderately high ionic strengths was found over the range of temperatures from 40 to 110 °C, having the theoretical Debye-Hiickel limiting slope and the intercept of logKs° at I=0. Assuming the same ionic size parameters, a1=a2, the solubility product (Ks°) of gibbsite was found to depend upon temperature up to 110 °C as follows: logKs°=−4064⁄T−1.54 or −4023⁄T−1.65. At high ionic strengths above 1.0, log(Ksaw) showed positive deviations from the straight line, which may be attributed to the formation of complex ions, e.g., Al2O(OH)62−, or the dehydration of Al(OH)4 to AlO(OH)2 and AlO2 ions.
  • Tadashi Hattori, Kenji Shirai, Miki Niwa, Yuichi Murakami
    1981 Volume 54 Issue 7 Pages 1964-1967
    Published: 1981
    Released: June 02, 2006
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    The infrared diffuse reflectance spectra of CaCO3 dispersed in KBr and Si were measured over a wide concentration range. The relation between relative reflectance and concentration varies with dispersing medium. The relation follows the Kubelka-Munk (K-M) equation only in the low concentration region. The deviation in the high concentration region from the K-M equation changes with wavelength and dispersing medium. The results over the whole concentration range can be interpreted by means of a modified K-M equation in which the difference in the scattering coefficients between the sample and the dispersing medium is taken into account. The tendency of scattering coefficients of CaCO3, KBr, and Si calculated by the modified Kubelka-Munk equation agrees with that of refractive indexes.
  • Hiromu Satake, Takeo Hisano, Sanae Ikeda
    1981 Volume 54 Issue 7 Pages 1968-1971
    Published: 1981
    Released: June 02, 2006
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    Sulfide, thiosulfate, and polysulfide ions in their mixtures were determined potentiometrically with a silvernitrate standard solution. These three species can be precisely determined from two titrations for each sample with the coefficient of variation of 0.3% at the concentration level of 5×10−4 M (1 M= 1 mol dm−3). One aliquot is titrated, after making the titrand acidic with an acetate buffer (pH=4), to get the end points of the sulfide and thiosulfate ions respectively, in the presence of free sulfur. The other is titrated, after the sulfitolysis of the sample solution, to show the end points of the sulfide and thiosulfate (the original thiosulfate plus the thiosulfate which is formed from polysulfide) ions in the presence of excess sulfite. The addition of calcium nitrate is effective in making the end points clear and accurate. This method was applied to determine these species in lixiviation water of blast-furnace slag.
  • Yoshiaki Onoue
    1981 Volume 54 Issue 7 Pages 1972-1974
    Published: 1981
    Released: June 02, 2006
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    Cellulose thin-layer chromatographic separation of chlorophyll a, b, and c, pheophytin a, b, and c, Zn(II) and Cu(II)-complexes of protoporphyrin-IX dimethyl ester (PPDE) was studied by using a light petroleum–acetone developing solvent system. The hRf values of metal–PPDE chelates were found to be virtually linearly related with the electronegativities-to-radius ratio (En/ri) of central-metal ions. The hRf values of metalloporphyrins become progressively greater with increase in En/ri values of the central metal. This suggests that a dominant factor influencing the hRf values of metal–porphyrins is the extent of electron transfer from the four nitrogens and/or the π-electron system of porphyrin to central metal.
  • Akira Iino, Atsushi Mizuike
    1981 Volume 54 Issue 7 Pages 1975-1977
    Published: 1981
    Released: June 02, 2006
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    Glass surfaces are bombarded by energetic neutral argon atoms or oxygen molecules, and the resulting sputtered ions are mass-analyzed. This technique has a higher depth resolution than conventional secondary-ion mass spectrometry. Quantitative depth-concentration profiles of sodium and potassium in the top layer of the surface (within several tens of nanometers of the surface) of Pyrex glass are obtained by the proposed technique.
  • Seichi Okeya, Hiroyuki Sazaki, Michiyo Ogita, Takako Takemoto, Yukio O ...
    1981 Volume 54 Issue 7 Pages 1978-1994
    Published: 1981
    Released: June 02, 2006
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    Reactions of the bis(β-diketonato)palladium(II) complexes with various nitrogen bases (L) afforded [Pd(β-dik)L2](β-dik), [PdL4](β-dik)2, or [Pd(β-dik)(β-dik-C)L] according to the natures of L and β-diketonate anions. Less basic ligands such as 1,1,1,5,5,5-hexafluoro- and 1,1,1-trifluoro-2,4-pentanedionates are readily removed by L to the outer sphere. Tendency of preferring the central-carbon-bonded state of the β-diketonate anion is related with the keto-favoring nature of its conjugate acid. Excess primary amines and pyridines can displace both of the β-diketonate ligands but secondary amines only one. These two types of compounds containing the 2,4-pentanedionate anion in the outer sphere undergo prompt deuteration of methine and amine protons by CDCl3. Tribenzylamine and 2,6-diphenylpyridine react with bis(1,1,1,5,5,5-hexafluoro-2,4-pentanedionato)palladium(II) to afford orthometallated products.
  • Yoshihisa Yamamoto, Masayasu Mori, Hidetaka Konno
    1981 Volume 54 Issue 7 Pages 1995-1998
    Published: 1981
    Released: June 02, 2006
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    Paramagnetic tetraammine-5-nitrosalicylato cobalt complex, paramagnetic μ-hyperoxo-dicobalt complexes and related diamagnetic compounds have been studied by X-ray photoelectron spectroscopy. In all these compounds, the binding energies of Co 2p electrons and their spin-orbit separation were those of usual Co(III) complexes. In the spectrum of paramagnetic tetraammine-5-nitrosalicylatocobalt salt, satellites appeared near the Co 2p peaks showing certain spin density at the cobalt atoms. At the same time, the C ls spectrum showed that considerable portion of carbon atoms has high binding energy suggesting delocalization of electron hole over the organic ligand. The O ls peaks in μ-hyperoxo complexes were ca. 0.6 eV higher than those in μ-peroxo complexes. Deconvolution of the O ls peak in the μ-OOH complex gave OH, =O–, and H2O peaks at the 1:1:1 ratio, supporting the μ-OOH formulation.
  • Hiroshi Kishi
    1981 Volume 54 Issue 7 Pages 1999-2004
    Published: 1981
    Released: June 02, 2006
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    Polyatomic negative ions for almost all of the elements in A-subgroups on the periodic table were tested by the spark discharge type ion source mass spectroscopy. A large number of polyatomic negative ions such as “polymer” negative ions, hydride negative ions, oxide negative ions, and carbide negative ions, could be detected. The results are discussed with reference to the reported values of electron affinities of the molecules and to the reported results by other methods of formation.
  • Hiroshi Kishi
    1981 Volume 54 Issue 7 Pages 2005-2009
    Published: 1981
    Released: June 02, 2006
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    Polyatomic negative ions for almost all of the elements in B-subgroups on the periodic table were tested by the spark discharge type ion source mass spectroscopy. Polyatomic negative ions such as hydride negative ions, oxide negative ions, and carbide negative ions could be detected. The results are discussed with reference to the reported results by other methods of formation.
  • Takakazu Yamamoto, Teiji Kohara, Akio Yamamoto
    1981 Volume 54 Issue 7 Pages 2010-2016
    Published: 1981
    Released: June 02, 2006
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    Thirteen complexes of a type NiR(Y)Ln (R=CH3 (Me), C2H5 (Et); Y=OC6H5, p-cyanophenoxo, 8-phenylphenoxo, 8-quinolinolato, OCOEt, OCOPh, acetophenone oximato, acetylacetonato, benzoylacetonato, Cl; L=trie thy lphosphine (PEt3), 2,2′-bipyridine (bpy)) have been prepared by reactions of dialkylnickel(II) complexes NiR2L2 (1) with the corresponding active hydrogen compounds HY. Reactions of 1 with R′COY (Y=OC6H5, OCOC6H5, Cl) also afford the NiR(Y)Ln type complexes with formation of unsymmetrical ketones RCOR′. Reactions of 1 with alcohols lead to dehydrogenation of alcohols to afford aldehydes or ketones. The NiR(Y)Ln type complexes have been characterized by elemental analysis and spectroscopies (IR, NMR, visible). NMR spectra of trans-NiMe(OCOPh)(PEt3)2, NiMe(acetophenone oximato)(PEt3) (11), NiMe(benzoylacetonato) (PEt3) show temperature dependence, indicating occurrence of rapid dynamic reactions on NMR time scale in these complexes. The acetophenone oximato ligand in 11 is proposed to serve as an oxa-, aza-π-allylic ligand on the bases of IR and NMR spectroscopies. NiEt(OCOC2H5)(bpy) (8), NiEt(OCOC6H5)(bpy), and NiEt(Cl)(bpy) (14) undergo disproportionation reaction to give NiEt2(bpy) and NiY2(bpy) type complexes. Diethyl ketone is also produced during the disproportionation of 8. Reactions of 14 with olefins having electron-withdrawing substituents afford NiCl2(bpy) and Ni(olefin)2(bpy).
  • Kisaburo Umemoto
    1981 Volume 54 Issue 7 Pages 2017-2022
    Published: 1981
    Released: June 02, 2006
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    An automatic coulometric Karl Fischer titrator capable of direct readout of the water titrated and the background of titration was constructed. Control of the generation of reagent was carried out by a digital counting method. The over- and under-titration was minimized by holding the level of reagent at the start and the end of titration as close as possible. Details of the circuit configuration were presented. The precision of determination was ca. ±2 μg and ±1–±2 μg for the automatic titration of 1 mg and 10–500 μg of water, respectively. Water of less than 20 μg was titrated within a precision of 1 μg by watching the drift and subsequent recovery of the blank level.
  • Mitsuru Sano, Hideo Yamatera
    1981 Volume 54 Issue 7 Pages 2023-2028
    Published: 1981
    Released: June 02, 2006
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    The X-ray photoelectron spectra (XPS) were measured in order to obtain the Nls and Cls core-orbital energies of ten ethylenediamine and 21 cyano complexes of transition metals. The difference between the Nls and Cls energies, ΔE, which was found to be hardly affected by the counter ion or by charging, was accurately determined for each complex. The trends observed in the ΔE values for these series of complexes are correlated with the electronic structures of the complexes by the use of Siegbahn’s equation. For the ethylenediamine complexes, the ΔE values are shown to be related to the σ donation. For the cyano complexes, the ΔE values are mainly controlled by the nitrogen charge, which is itself closely connected with the π back-donation. Demonstrative of the importance of the π back-donation are the cases of [Fe(CN)6]4− and [Fe(CN)6]3−, where the decrease in the negative charge from the former to the latter is found to occur dominantly (76%) in the nitrogen atoms. Molecular orbital (MO) calculations in the discrete variational Xα (DV-Xα) scheme were performed for a few series of the cyano complexes, giving results consistent with the XPS results.
  • Yuki Fujii, Makoto Matsufuru, Akira Saito, Sakiko Tsuchiya
    1981 Volume 54 Issue 7 Pages 2029-2038
    Published: 1981
    Released: June 02, 2006
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    Cobalt(III) complexes containing N-alkyl-L-alanine and a Schiff base ligand, β2-[Co(α-Me-sal2en)(N-R-L-ala)] (where α-Me-sal2en represents the dianion of N,N′-ethylenebis(a-methylsalicylideneamine) and N-R-L-ala denotes the anion of titled amino acids), have been prepared. They were characterized by the use of the absorption, circular dichroism, and 1H NMR spectra of the complexes. They showed quite high stereoselectivity for ΛRS2-configuration: 93% for N-methyl-L-alanine, and almost 100% for N-benzyl-L-alanine and N-benzyl-N-methyl-L-alanine. The similar β2-Co(sal2-(S,S-chxn) complexes with N-benzyl-L- and N-benzyl-D-alanines, where sal2-(S,S)-chxn represents the dianion of (1S,2S)-N,N′-1,2-cyclohexylenebis(salicylideneamine), have been synthesized to investigate the stereospecificity of the complex toward N-benzyl-L-alanine. It was found that Co(sal2-(S,S)-chxn) complex reacts with N-benzyl-L-alanine in a high stereospecificity (93–94% at the 1 : 2 reaction molar ratio between the complex and racemic N-benzylalanine, and almost 100% at the 1 : 100 molar ratio). The above phenomena were explained in terms of the thermodynamic selectivity of the complexes.
  • Takumi Oshima, Toshikazu Nagai
    1981 Volume 54 Issue 7 Pages 2039-2044
    Published: 1981
    Released: June 02, 2006
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    Kinetic studies have been made of the reactions of fifteen meta- and para-substituted diphenyldiazomethanes(DDMs) with 2,3-dichloro-5,6-dicyanobenzoquinone(DDQ) in benzene. The second-order rate constants, k, increased with the electron-donability of the substituents, and the value could be correlated with the Yukawa-Tsuno equation: logkk0=−2.33(σ0+0.47Δ\barσR+)+0.017, (r=0.996,30 °C). The ρ value, −2.33, indicates the development of a positive charge at the diazo carbon in the transition state, while the R value, 0.47, confirms the moderate stabilization of the positive charge by the π-electronic contribution of the para substituents. The rate constants have also been determined for the reaction of diphenyldiazomethane(DDM) with DDQ in 28 aprotic solvents. The effects of solvents can be interpreted in terms of the basicity and the steric nature of the solvents. The products of these reactions were poly(2,3-dichloro-5,6-dicyanohydroquinone benzhydryl ether)s, which were easily convertible into benzophenones and α,α-dimethoxydiphenylmethane, together with 2,3-dichloro-5,6-dicyanohydroquinone, under the influence of water and methanol. These solvolysis products were also obtained in excellent yields in the initial presence of these additives.
  • Kunio Okuhara
    1981 Volume 54 Issue 7 Pages 2045-2052
    Published: 1981
    Released: June 02, 2006
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    Compounds of the type AZCF=CCl2, prepared from AZA (thiophene, furan, and p-dibromobenzene; Z=2,5-thiophenediyl, 2,5-furandiyl, and p-phenylene; A=H or Br), were converted into CCl2=CFZC≡CH, CCl2=CFZC≡CCF=CCl2, and CCl2=CFZC≡CSi(CH3)3 in a one-flask procedure via LiZC≡CLi. The products were further converted into acetylenic compounds such as (CH3)3SiC≡CZC≡CSi(CH3)3 and (CH3)3SiC≡CZC≡C–C≡CSi(CH3)3. 1-Ethynyl-4-(1,3-butadiynyl)benzene was isolated. 2,5-Diethynylthiophene and -furan were prepared in two steps from thiophene and furan, respectively, via CCl2=CFZCF=CCl2. By treatment with copper (II) acetate hydrate in pyridine, (CCl2=CFZC≡C–)2 were obtained not only from CCl2≡CFZC≡CH but also from CCl2=CFZC≡CSi(CH3)3.
  • Makoto Komiyama, Hidefumi Hirai
    1981 Volume 54 Issue 7 Pages 2053-2056
    Published: 1981
    Released: June 02, 2006
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    A selective attack of dichlorocarbene at the para-position of phenolate has been achieved by using α-cyclo-dextrin and the reaction mechanism has been studied by the 13C-NMR and 1H-NMR spectroscopy. The attack of the carbene at the para-position of phenolate (82%) is dominant over the attack at the ortho-position (18%) in the presence of 0.15 mol dm−3 of α-cyclodextrin, which is in contrast with the predominance of the ortho-attack (59%) over the para-attack (41%) in the absence of α-cyclodextrin.
  • Yoshiro Ogata, Makoto Kimura, Yoshinori Kondo
    1981 Volume 54 Issue 7 Pages 2057-2060
    Published: 1981
    Released: June 02, 2006
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    Hypochlorite oxidation of simple α-amino acids (the Strecker degradation) in aqueous solutions has been studied in the dark and under UV-irradiation. UV-spectra, iodometry, and amino acid determination (2,4-dinitrofluorobenzene method) suggest that the intermediate N-chloro amino acid is formed quickly at an initial stage, then its slow oxidative decomposition takes place to give aldehyde, carbon dioxide, and ammonia. The mechanism is also supported by the fact that the oxidation follows the first-order rate expression; −d[RCH(NH2)CO2H]⁄dt=k[1[RCH(NHCl)CO2H]. UV-irradiation was found to promote remarkably the degradation of N-chloro amino acid. When equimolar amounts of amino acid and hypochlorite were used, the products such as unreacted amino acid, ammonia, and aldehyde were analogous to those of the dark reaction. The use of a large excess of hypochlorite under irradiation enables complete oxidative degradation of amino acid to carbon dioxide,, water, and nitrogen. Its application to waste water treatment is discussed.
  • Yoshiro Ogata, Yasuhiko Sawaki, Yasuyuki Tsukamoto
    1981 Volume 54 Issue 7 Pages 2061-2064
    Published: 1981
    Released: June 02, 2006
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    Oxidation of benzaldehydes and dimethyl sulfoxide with peroxomonophosphoric acid (PMPA) has been studied in 40% aqueous EtOH in order to examine the reactivity of undissociated and dissociated PMPA in comparison with that of peroxycarboxylic acid. The reactivity for DMSO was in the order RCO3>H3PO5>H2PO5>RCO3H>HPO52−. As in the peroxycarboxylic acid oxidation, PMPA oxidation of substituted benzaldehydes afforded phenols by aryl migration and benzoic acids by hydride migration. The product ratio changed with substituents and pH; salicylaldehyde (o-HO) gave only catechol by aryl migration, while p-chloro and unsubstituted benzaldehydes afforded benzoic acids predominantly. The oxidation of aldehydes bearing p-MeO and p-Me was a borderline case and the migratory ratio of Ar∼/H∼ was higher at lower pH, i.e., the order being H3PO5>H2PO5>HPO52−. The substituent effect in the apparent kobsd values was very small (i.e., ρ≈0), but the effect for aryl migration (kAr∼) estimated from product selectivity gave ρ=−2.88(σ). The rate for hydride migration (kH∼) resulted in ρ=1.7 and 2.0 (σ). Reactivity of PMPA in each dissociated form was compared with that of RCO3H.
  • Yasunori Iwama, Masashi Aragi, Motohide Sugiyama, Kasumi Matsui, Yasut ...
    1981 Volume 54 Issue 7 Pages 2065-2067
    Published: 1981
    Released: June 02, 2006
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    Triphenylselenonium halides were readily prepared in good yields by the one-step reaction of seleninyl chloride with phenylmagnesium halides, followed by treatment with hydrogen halides. The yields of triphenylselenonium halides are markedly affected by the molar ratio of seleninyl chloride to the phenylmagnesium halides. In order to interpret the above results, some probable intermediates, such as diphenyl selenoxide, dibromodiphenylselenium, and diphenyl selenide, were investigated by allowing them to react with the phenylmagnesium halides. A pathway which consists of competitive and successive reactions is discussed.
  • Akira Sugimori, K\={o}tar\={o} Takada, Tsutomu Kimura, Junji Kamimura
    1981 Volume 54 Issue 7 Pages 2068-2071
    Published: 1981
    Released: June 02, 2006
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    Iron(III) and copper(II) chelated by 2-pyridinecarboxylate bring about the photochemical decarboxylation of the ligand via the electron transfer from carboxylate to metal ions to give pyridine and 2,2′-bipyridine (for Fe(III)) or 2-pyridinol (for Cu(II)). In the presence of iron(III), ruthenium(III), and copper(II), 3-pyridinecarboxylic acid gives photochemically 2,2′-bipyridine-3,5′-dicarboxylic acid without decarboxylation. 4-Pyridinecarboxylic acid is photo-resistant both in the presence and in the absence of iron(III) and copper(II).
  • Yoshio Okahata, Hirotaka Ihara, Toyoki Kunitake
    1981 Volume 54 Issue 7 Pages 2072-2078
    Published: 1981
    Released: June 02, 2006
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    A study was carried out on the reaction of p-nitrophenyl phosphates with hydroxamate nucleophiles in water in the presence of dialkylammonium bilayer membranes. With ethyl bis(p-nitrophenyl) phosphate, clean second order kinetics was observed for all the hydroxamate nucleophiles, two equivalents of p-nitrophenol being released in most cases. In contrast, a complex kinetics was observed for octadecylbis(p-nitrophenyl)phosphate. The second cleavage process of this long-chain substrate by a long-chain hydroxamate was affected by the fluidity of the matrix membrane, an inflection region being present in the Arrhenius plots near the phase transition temperature(Tc) of the 2C16N+2C1 membrane. The activation energy was 14 and 21 kcal/mol at temperatures above and below Tc, respectively. Similar changes in the activation energy had been observed for decarboxylation and proton abstraction.
  • Shin-ichi Kamiyama, Akira Kasahara, Taeko Izumi, Iwao Shimizu, Hiroyuk ...
    1981 Volume 54 Issue 7 Pages 2079-2082
    Published: 1981
    Released: June 02, 2006
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    [3.3](1,1′)Ruthenocenophane-2,14-diene-1,16-dione, [5.5](1,1′)ruthenocenophane-2,14,17,29-tetraene-1,16-dione and their ferrocenoruthenocenophane homologs were synthesized by using an intermolecular base-catalyzed condensation.
  • Tomoya Sakai, Masahiko Ishizaki, Katsuaki Kobayashi, Masafumi Goto
    1981 Volume 54 Issue 7 Pages 2083-2088
    Published: 1981
    Released: June 02, 2006
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    The enhancement of formose formation in the presence of several hydroxy oxo compounds was examined in an aqueous Ca(OH)2 solution. Four terminal hydroxy oxo compounds, 2-hydroxyacetophenone, 1,3-dihydroxyacetone, DL-glyceraldehyde, and D-glucose, were confirmed to accelerate the reaction, but two internal hydroxy oxo compounds, 2-hydroxypropiophenone and acetoin, were found not to be effective. The acceleration efficiency was larger for a system in which hydroxy oxo compounds were introduced to an aqueous mixture of Ca(OH)2 and formaldehyde than for a system in which formaldehyde was introduced to an aqueous mixture of Ca(OH)2 and the hydroxy oxo compounds. The difference in the acceleration efficiencies between the two procedures of reagent introduction was large for 2-hydroxyacetophenone and 1,3-dihydroxyacetone. This is accounted for by the rapid conversions of the added hydroxy oxo compounds in an aqueous Ca(OH)2 solution.
  • Kazuhisa Murata, Akio Matsuda
    1981 Volume 54 Issue 7 Pages 2089-2092
    Published: 1981
    Released: June 02, 2006
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    The hydrocarbonylation of ethene with CO and H2O produces diethyl ketone with a high selectivity of 99±1%(propanal 1±1%); a Co2(CO)8–phosphine system is used as an efficient catalyst, which is also active for the homogeneous water-gas shift reaction. The effects of the reaction parameters(CO pressure, temperature, and ethene and H2O concentrations) on the selectivity and activity are examined for the Co2(CO)8–1,2-bis(diphenylphosphino)ethane (diphos) system; the selectivity to yield the ketone is fairly high under the variety of conditions studied here. Evidence suggests that the active species which catalyze the water-gas shift reaction participate in the hydrocarbonylation of ethene.
  • Masayuki Ito, Minoru Hirota
    1981 Volume 54 Issue 7 Pages 2093-2098
    Published: 1981
    Released: June 02, 2006
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    Enthalpies of intramolecular hydrogen bond formation (ΔH) were determined for a series of α-mono- and α,α-dialkyl-o-methoxybenzyl alcohols and related compounds. The −ΔH values of the unsubstituted and α,α-dialkyl-o-methoxybenzyl alcohols are more than 2.5 kJ mol−1, while those for the corresponding α-monoalkyl derivatives are at most 1 kJ mol−1. This tendency is in accordance with the results on their ΔvOH and εbf values, showing the hydrogen bonded conformations of the α-monoalkyl derivatives are less favorable than those of the other alcohols in discussion. Molecular force field calculations on α-alkyl- and α,α-dialkylbenzyl alcohols were also carried out. The results shows that the hydroxyl/aryl coplanar conformation (ω=0°) is the most stable for the unsubstituted and α,α-dialkylbenzyl alcohols and the hydroxyl/aryl non-coplanar conformation (ω=30°) for α-alkylbenzyl alcohols. Since the OH···O distance might be farther and, hence, the overlap between the unshared electron pairs on the methoxyl oxygen and the anti-bonding OH orbital might be less in the non-coplanar conformation, α-monoalkyl-o-methoxybenzyl alcohols are less favorable than the corresponding α,α-dialkyl derivatives in the intramolecular hydrogen bond formation.
  • Takashi Matsumoto, Sachihiko Imai, Hiroyuki Kawashima, Masanori Mitsuk ...
    1981 Volume 54 Issue 7 Pages 2099-2102
    Published: 1981
    Released: June 02, 2006
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    The structure of shonanol was restudied and found to be 12-hydroxyabieta-2,8,11,13-tetraen-1-one (1) by the following synthesis. A Grignard reaction of methyl (+)-12-methoxyabieta-8,11,13-trien-18-oate with phenylmagnesium bromide, followed by treatment with lead tetraacetate and calcium carbonate afforded a mixture of Δ3, Δ4, and Δ4(18)-19-nor compounds. This was oxidized with selenium dioxide to give (+)-12-methoxy19-norabieta-4(18),8,11,13-tetraen-3α-ol. This alcohol was converted to (+)-12-methoxyabieta-5,8,11,13-tetraen-3-one (6) by the known procedure. Reduction of 6 with lithium aluminium hydride, followed by catalytic hydrogenation, yielded (+)-12-methoxyabieta-8,11,13-trien-3β-ol (8) and a small amount of its cis isomer. The compound (8) was then converted to (+)-12-methoxyabieta-1,8,11,13-tetraen-3-one (12) by a series of reactions: oxidation with pyridinium chlorochromate, bromination with pyridinium tribromide, and dehydrobromination with lithium carbonate and lithium bromide. Demethylation of 12 with boron tribromide gave (+)-12-hydroxyabieta-1,8,11,13-tetraen-3-one. Oxidation of 12 with alkaline hydrogen peroxide, followed by treatment with hydrazine hydrate, gave (+)-12-methoxyabieta-2,8,11,13-tetraen-1α-ol; this was oxidized with Jones reagent to give the corresponding 1-oxo compound. The 1-oxo compound was finally demethylated with boron tribromide to yield (+)-1, whose spectra were identical with those of natural shonanol.
  • Tian-hsi Tsai, Mamoru Ai, Atsumu Ozaki
    1981 Volume 54 Issue 7 Pages 2103-2106
    Published: 1981
    Released: June 02, 2006
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    12-Molybdophosphoric acid effective for oxidation of crotonaldehyde to furan was modified in two ways; by adding various cations and by replacing Mo with V or W. Among cations caesium was proved to be most effective in improving the furan yield, by decreasing reactivity of product furan relative to crotonaldehyde, thus minimizing the secondary oxidation of furan to maleic anhydride. The highest efficiency of caesium is associated with its high basicity, while the active catalyst species responsible for the furan formation is acidic in nature. The replacement of Mo by V or W gave rise to decreased activity, in contrast to other oxidations on the same catalyst. The unique character of crotonaldehyde oxidation is discussed.
  • Toshio Kurihara, Masaru Sugizaki, Itaru Kime, Makoto Wada, Oyo Mitsuno ...
    1981 Volume 54 Issue 7 Pages 2107-2112
    Published: 1981
    Released: June 02, 2006
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    The reagent formed by the reaction of diethyl azodicarboxylate (1) and triphenylphosphine (2) reacted with alcohols and ethyl cyanoacetate (6) to give alkylated products in 30–80% yields. When ethyl acetoacetate, 1,3-cyclopentanedione, or 1,3-cyclohexanedione was used in place of 6, the corresponding O-alkylated products were obtained. The reaction of either (S)-(−)-ethyl lactate or (S)-(−)-ethyl 2-hydroxy-3-phenylpropionate with 1, 2, and 6, followed by hydrolysis resulted in the formation of (S)-(−)-methylsuccinic acid or (S)-(−)-benzylsuccinic acid. The results indicate that nearly complete inversion of the configuration takes place in the alkylation step.
  • Shoji Zushi, Yoshio Kodama, Yoshimasa Fukuda, Ken Nishihata, Motohiro ...
    1981 Volume 54 Issue 7 Pages 2113-2119
    Published: 1981
    Released: June 02, 2006
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    The conformations have been studied, by means of NMR spectroscopy, for a series of 1-alkyl-substituted 2-phenylethyl alcohols with the structure C6H5CH2CH(OH)–R, where R=CH3 (1), C2H5 (2), i-C3H7 (3), and t-C4H9 (4). It has been suggested that a rotamer in which the phenyl group is oriented gauche to the alkyl (R) and anti to the hydroxyl group is most populated in the conformational equilibria of 13. Another rotamer (in which Ph is anti to R) has, on the other hand, been suggested to be preferred in the conformational equilibrium of 4. The results have been discussed in the light of the presence of an attractive alkyl-phenyl interaction (CH–π interaction).
  • Shigeo Jo, Shigeo Tanimoto, Toyonari Sugimoto, Masaya Okano
    1981 Volume 54 Issue 7 Pages 2120-2123
    Published: 1981
    Released: June 02, 2006
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    The reaction of various phenols with 2-ethoxy-1,3-dithiolane proceeded smoothly in the presence of BF3·Et2O to afford 1,3-dithiolan-2-ylated phenols, which were readily hydrolyzed to the corresponding aldehydes. This process was also extended to N,N-dimethylaniline and indole.
  • Yoshiaki Ohgo, Seiji Takeuchi, Yukikazu Natori, Juji Yoshimura
    1981 Volume 54 Issue 7 Pages 2124-2135
    Published: 1981
    Released: June 02, 2006
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    The catalytic asymmetric hydrogenations of α-diketones, α-keto carboxylates, α-(acylamino)acrylates, α-phenylacrylophenone, and α-phenylacrylate were examined with bis(dimethylglyoximato)cobalt(II)–chiral cocatalyst (amino alcohol) and with simple achiral base coordinated bis(dimethylglyoximato)cobalt(II)–chiral cocatalyst (amino alcohol) systems. These gave corresponding optically active reduction products, and in some cases, optically active reductive dimerization products. High degrees of enantioselectivities (≈78%) are achieved in the hydrogenation of α-diketones. Evidence for non-binding of chiral base to cobalt complexes was presented in the case of latter system, i.e., it was shown that the catalytic site and the enantioselectivity-determining site are separated in this system, as in enzymes. The importance of protonated chiral bases for enantioselection was also shown. Based on these results and the stereochemical correlations between structures of the chiral bases and those of the products, a mechanism for this asymmetric hydrogenation was proposed.
  • Seiji Takeuchi, Yoshiaki Ohgo
    1981 Volume 54 Issue 7 Pages 2136-2141
    Published: 1981
    Released: June 02, 2006
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    As a new type of chiral cocatalyst in the achiral base-coordinated bis(dimethylglyoximato)cobalt(II)–chiral cocatalyst system, tertiary amines with an amide group at α- or β-carbon were prepared, and asymmetric hydrogenation was examined by using them. The optical yield reached 34.5% enantiomeric excess(ee) by using N-[(2S,3S)-2-acetoxy-3-dimetnylamino-3-phenylpropionyl]-(R)-α-methylbenzylamine; this is the highest value attained so far in the asymmetric hydrogenation of methyl N-(acetylamino)acrylate with this system. The enantioselectivity in the hydrogenation of methyl N-(acetylamino)acrylate was reversed with a configurational alteration of the α-methylbenzylamine moiety of N-[N,N-dimethyl-(S)-phenylalanyl]-α-methylbenzylamine, while it was not reversed in the hydrogenation of benzil by the configurational alteration. From these facts, it is deduced that the hydrogen bond between amide groups of the chiral amino carboxamides and methyl N-(acetylamino)acrylate may act as an attractive force to enhance the enantioselectivity of the asymmetric hydrogenation.
  • Kazuo Miyauchi, Kimiaki Hori, Tsuguji Hirai, Matsuji Takebayashi, Tosh ...
    1981 Volume 54 Issue 7 Pages 2142-2147
    Published: 1981
    Released: June 02, 2006
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    The proton acid-catalyzed decomposition of 3-aryl-2-diazo-3-hydroxy-1-phenylpropanone (1) gave aryl and hydrogen migration products. The former was the enol-form (2) of 2-aryl-3-phenyl-1,3-propanedione and the latter was the enol- (3) and keto-form (4) of 1-aryl-3-phenyl-1,3-propanedione. The product ratios, 2/(3+4), were affected by the catalysts and solvents used. More polar solvents favored the formation of aryl migration products (2). On the other hand, the BF3-catalyzed decomposition of 1 gave acetylenic ketones as main products along with 2, 3, and 4. The TsOH-catalyzed decomposition of 2-diazo-3-hydroxy-3-phenyl-1-indanone, (cyclic α-diazo β-hydroxy ketone), gave 2-phenyl-1,3-indandione quantitatively through phenyl migration.
  • Shigeomi Horito, Yuji Ohashi, Nobert Gassner, Juji Yoshimura, Yoshio S ...
    1981 Volume 54 Issue 7 Pages 2147-2150
    Published: 1981
    Released: June 02, 2006
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    The molecular and crystal structure of octa-O-acetyl-tris(N-ethoxycarbonyl)destomycin A tetrahydrate, C45H65N3O27·4H2O, has been determined by X-ray analysis. The space group is P21 with a=14.738(4), b=17.391(4), c=12.171(4) Å, β=105.58(4)°, and Z=2. The structure was solved by the direct method, and the least-squares refinement using 4008 reflections led to the final R value of 0.12. The configuration of the ortho ester carbon atom is (R). The D-talose moiety has the boat conformation whereas the other rings are in the chair form.
  • Tamejiro Hiyama, Yoshitomi Morizawa, Hajime Yamamoto, Hitosi Nozaki
    1981 Volume 54 Issue 7 Pages 2151-2160
    Published: 1981
    Released: June 02, 2006
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    Ring-opening alkylation of cyclopropylmethyl acetates was studied. The acetoxyl group of 7-(1-acetoxyheptyl)norcarane is substituted by the alkyl group upon treatment with trialkylaluminium, but alkylation of trans-1-(1-acetoxyethyl)-2-phenylcyclopropane with trialkylaluminium gives rise to trans-5-phenyl-2-alkenes. The reaction of (1S,2S)-2-phenylcyclopropylmethyl acetate with trimethylaluminium resulted in the complete loss of optical activity to give racemic 4-phenyl-1-pentene. Alkylation of trans-1-(1-acetoxy-3-phenylpropyl)-2-vinylcyclopropane with trialkylaluminium proceeds under regioselective ring-opening to give 3-alkylated trans-8-phenyl-1,5-octadiene (selectivity 73–83%). The regio- and stereochemistry of homoconjugate addition to activated vinylcyclopropanes having a doubly carbonyl substituted ring carbon was studied. Trialkylaluminium on addition to diethyl 2-vinylcyclopropane-1,1-dicarboxylate in a 1,5-manner afford diethyl (2-alkyl-3-butenyl)propanedioate (over 96% selectivity). In contrast, the reaction of this cyclopropane with tetraalkylaluminiumlithium takes place in a 1,7-manner to give diethyl (trans-4-alkyl-2-butenyl)propanedioate with 88–92% selectivity. Clean regiocontrol of the reaction is observed in the methylation of ethyl exo-6-(trans-1-propenyl)-2-oxobicyclo[3.1.0]hexane-1-carboxylate with trimethylaluminium or tetramethylaluminiumlithium. Alkylation with trimethylaluminium proceeds with 86% inversion of the configuration at C(6) of the substrate, affording (2R*,3R*)-2-ethoxycarbonyl-3-[(S*)-trans-1-methyl-2-butenyl]cyclopentanone which is transformed into neonepetalactone.
  • Takakazu Yamamoto, Teiji Kohara, Akio Yamamoto
    1981 Volume 54 Issue 7 Pages 2161-2168
    Published: 1981
    Released: June 02, 2006
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    Reactions of monoalkylnickel(II) complexes, NiR(Y)L2 (R=CH3, C2H5; Y=Cl, suc(succinimido), pht(phthalimido), OC6H4-p-CN; L=1/2 bpy (2,2′-bipyridine), PEt3 (triethylphosphine)), with CO afford monoacylnickel(II) complexes, Ni(COR)(Y)L2, which are characterized by elemental analysis and spectroscopies (IR and NMR). Reactions of the acylnickel(II) complexes with alcohols and aniline give the corresponding esters and amides, respectively. Exposure of Ni(COR)(Y)L2 to dry air leads to oxidation of RCO to a RCOO ligand giving a complex formulated as Ni(OCOR)(Y)L2. Reactions of dimethylnickel(II) complexes, Ni(CH3)2L2 (L=1/2 bpy, PEt3, 1/2 dpe (1,2-bis(diphenylphosphino)ethane, 1/2 dpp (1,3-bis(diphenylphosphino)propane), with carbon monoxide afford acetone and/or 2,3-butanedione in medium to high yields, the acetone/2,3-butanedione ratio varying with the ligand L, reaction temperature, and additives such as maleic anhydride and triphenylphosphine. Generally the acetone/2,3-butanedione ratio decreases with increase in thermal stabilities of Ni(CH3)2L2. Ni(C2H5)2(bpy) and Ni(n-C3H7)2(bpy) give 3-pentanone and 4-heptanone, respectively, on treating them with CO, whereas Ni(C2H5)2(dpe) produces C2H5CHO and C2H4.
  • Masafumi Matsuzawa, Kazusuke Kubo, Hisashi Kodama, Masuo Funabashi, Ju ...
    1981 Volume 54 Issue 7 Pages 2169-2173
    Published: 1981
    Released: June 02, 2006
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    The title compounds were synthesized from L-arabinose and D-glucose as intermediates to a few naturally occuring branched-chain sugars. Oxidation conditions of precursors to the corresponding 4-uloses were examined.
  • Tatsuo Ohgushi
    1981 Volume 54 Issue 7 Pages 2174-2179
    Published: 1981
    Released: June 02, 2006
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    Zeolite A was synthesized in the sodium form with the composition Na12(AlO2·SiO2)12(NaAlO2)δ·nH2O, 0≤δ≤1. A new method was developed for the determination of the δ-value of the non-stoichiometric part in the product. It consists of repeated ion exchanges of zeolite with TINO3 (or BaCl2), and determination of the residual amount of Na+ in the zeolite as a function of the number of treatments. The Kδ/δ value was determined from a linear plot, where Kδ is a selectivity coefficient of the ion exchange reaction between Tl+ (or Ba2+) and Na+ in the non-stoichiometric part. The Kδ value was taken from the observed Kδ/δ value, the δ-value being obtained by chemical analysis. The δ-value of a sample can be determined by introducing the Kδ-value into Kδ/δ. An approximate δ-value can be estimated from a break point of the curve, log(residual amount of Na+) vs. the number of times of treatment.
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