Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
Volume 56 , Issue 12
Showing 1-50 articles out of 65 articles from the selected issue
  • Ken-ichi Okamoto, Shu Nakajima, Akira Itaya, Shigekazu Kusabayashi
    1983 Volume 56 Issue 12 Pages 3545-3548
    Published: 1983
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    2-(p-Decyloxybenzylideneamino)-9-nuorenone (DBAF), with a large π-electronic group, showed a transient photocurrent induced by the strongly-absorbed light from a N2 gas laser in the nematic, monotropic smectic, and isotropic liquid states. This photocurrent seemed to be due to the space-charge-limited current. The drift mobilities of the positive and negative charge carriers (μp and μn respectively) were determined from the peak time. The μn was ten times larger than μp, while the activation energies were identical. The modified Walden rule was valid in the nematic state ranging from 90 °C to 135 °C. The nematic mixtures of DBAF and N-(p-methoxybenzylidene)-p-butylaniline also showed a similar transient photocurrent, the magnitude of which increased significantly with an increase in the DBAF content. The mobilities were independent of the DBAF content and were nearly equal to those in nematic DBAF at the same viscosity, η: that is, μn=3×105, and μp=2.5×10−6 cm2/V s at η=0.026 Pa s. These facts indicate that the nature of the carrier transport of the photoconduction is not electronic, but ionic. The O2 and the cation radical of DBAF are proposed as the ionic carrier species for both nematic DBAF and the nematic mixtures.
  • Motosuke Naoki, Manabu Matsushita
    1983 Volume 56 Issue 12 Pages 3549-3555
    Published: 1983
    Released: June 27, 2006
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    Volumetric data on the supercooled liquid state and on the glassy state are reported for a binary mixture of triphenylchloromethane and o-terphenyl. In the supercooled liquid state, the thermal expansivity, the isothermal compressibility, and their temperature dependences of the mixture are much samller than those of simple molecular liquids and are almost the same order of magnitude as those of polymer liquids. The glass of the mixture also closely resembles polymer glasses in the apparent thermodynamic properties. Some representative lattice-like liquid theories are applied to the pressure-volume-temperature relations of the supercooled liquid sample, with the aid of the principle of corresponding states.
  • Koichiro Miyajima, Masahiro Sawada, Masayuki Nakagaki
    1983 Volume 56 Issue 12 Pages 3556-3560
    Published: 1983
    Released: June 27, 2006
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    The viscosities and densities at 15, 25, and 35 °C, and activity coefficients at 25 °C for the aqueous solutions of α- and γ-cyclodextrins were measured, and the results were interpreted in terms of solute-solvent and solute-solute interactions. The concentration and temperature dependences of viscosities and apparent molar volumes are almost similar to those of linear saccharides, i.e. maltose and maltotriose, indicating that α- and γ-cyclodextrins are structure forming solutes. However, the concentration dependences of activity coefficients of cyclodextrins are significantly different from those of maltose and maltotriose. The results were tentatively assigned to the formation of dimer in aqueous solutions.
  • Katsunosuke Machida
    1983 Volume 56 Issue 12 Pages 3561-3565
    Published: 1983
    Released: June 27, 2006
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    A general method has been developed to describe the atomic motion along a given intrinsic reaction coordinate (IRC) in the vicinity of the potential minimum of a polyatomic molecule whose anharmonic force constants are known experimentally or theoretically. The components of the position vector of a configuration point on an IRC in the normal coordinate space are expanded as power series of the path length from the origin measured along the IRC. Explicit expressions of the expansion coefficients up to the third order have been given in terms of the normal frequencies and the anharmonic force constants with respect to the normal coordinates. The atomic loci along the IRC are given by transformation from the normal coordinates to the Cartesian displacements. Through application to formaldehyde and water, the method has proved to be useful to check if a given normal coordinate can be connected to any dissociation path on large distortion of the molecule.
  • Akiko Ikekawa, Sohachiro Hayakawa
    1983 Volume 56 Issue 12 Pages 3566-3570
    Published: 1983
    Released: June 27, 2006
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    The effect of ball-milling on X-ray diffraction diagrams, IR spectra, DTA and DSC thermograms of hexobarbital was investigated. It was found that the regularity at the crystal part changed upon ball-milling without any diluent. In addition to this change, an amorphous part increased upon ball-milling with microcrystal-line cellulose (MCC). The solubility in a KH2PO4–Na2HPO4 buffer solution (pH 6.0) also increased upon ball-milling with MCC, though the solubility did not change without MCC. The analysis of IR spectra indicated that hydrogen bonds were formed between the C=O group of hexobarbital and the OH group of MCC upon ball-milling. Both the increase in the amorphous part and solubilization of hexobarbital upon ball-milling were attributed to the stabilization of the amorphous state caused by the interaction with MCC.
  • Hidetsugu Nakai, Shunsuke Takenaka, Shigekazu Kusabayashi
    1983 Volume 56 Issue 12 Pages 3571-3377
    Published: 1983
    Released: June 27, 2006
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    In order to examine the liquid crystalline properties of coumain, 3-X- and 7-Y-substituted coumarins where X=cyano and n-alkoxycarbonyl, and Y=4-n-alkyl- and 4-n-alkoxybenzoyl, 4-alkoxycinnamoyloxy, 4′-alkyl- and 4′-alkoxy-4-biphenylylcarbonyloxy, and 4-(4-alkoxybenzoyloxy)benzoyloxy (4) groups have been prepared. The compounds with X=alkoxycarbonyl group tend to exhibit strong smectic properties, and compounds with X=cyano exhibit stable nematic phases, whereas the coumarin core seems to facilitate a lateral separation of molecules in the mesophase due to its large molecular breadth. The heptyloxy homolog of 4 exhibits a reentrant behavior of the C–Nre–SA–N–I type. The thermal properties are discussed in terms of the polarity and polarizability of coumarin, and the molecular structure. The dielectric properties of the compounds have also been examined and discussed in terms of the polarity of the coumarin core.
  • Keisaku Kimura, Shunji Bandow
    1983 Volume 56 Issue 12 Pages 3578-3584
    Published: 1983
    Released: June 27, 2006
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    Three new methods for the preparation of metal colloid in organic solvent are presented. These methods were the matrix isolation method, the gas flow-cold trap method and the gas flow–solution trap method; the latter was found to give a good colloid solution for the optical measurements. The metals reported are high purity Ag, Au, Cu, In, Al, Ca, Sn, and Pb. The stability of the colloid is dependent on the kind of metals: Al, In, Au, and Ag are stable, and Pb, Sn, Ca, and Cu are unstable. The optical absorption spectra of these sols were measured in ethanol solution in Ar atmosphere. They are discussed in relation to those reported on the solid matrix or on the solid substrate.
  • Koji Saito, Akihiro Yoshino, Tadayoshi Yoshida, Kensuke Takahashi
    1983 Volume 56 Issue 12 Pages 3585-3587
    Published: 1983
    Released: June 27, 2006
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    The 1H and 31P NMR spectra of phenylphosphonous dichloride dissolved in a nematic phase of N-(p-ethoxybenzylidene)-p-butylaniline (EBBA) have been analyzed, and the structure of the proton and phosphorus skeleton has been determined.
  • Hiroyasu Sato, Masahiro Kawasaki, Kazuo Kasatani, Nobuaki Nakashima, K ...
    1983 Volume 56 Issue 12 Pages 3588-3594
    Published: 1983
    Released: June 27, 2006
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    The interaction of 3,3′-diethylthiacarbocyanine iodide, a cationic dye, with sodium dodecyl sulfate (SDS), an anionic detergent, was studied as a function of the concentration of SDS ([SDS]) above and below the critical micelle concentration (cmc). The [SDS]-dependent fluorescence spectra, quantum yield and decay measurements revealed the deaggregation of the dye above the cmc and the formation of the dye–SDS aggregate below the cmc.
  • Takahiro Masuda, Ryoji Gunji, Takako Kimura, Kotaro Yamauchi
    1983 Volume 56 Issue 12 Pages 3595-3599
    Published: 1983
    Released: June 27, 2006
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    A transient absorption, which is relatively long-lived, was found in a flash photolysis of aqueous potassium chloride containing 5-aminouracil. The transient absorption with a peak at about 335 nm was assigned to an intermediate produced from 5-aminouracil through a one-electron oxidation by dichloride anion radical. For the intermediate, a possible structure is proposed to explain its long life-time. On the basis of the transient absorption, a determination of the rate constant for the reaction of 5-aminouracil with dichloride anion radical was carried out by use of a competition kinetics. The value of (2.9±0.2)×108 dm3 mol−1 s−1 was obtained as the rate constant on the basis of rate constants of several reference compounds. By comparing the values obtained by the competition method with those estimated by a direct analysis of the decay rate of dichloride anion radical, the validity of the competition method was examined.
  • Yasuyuki Takeda
    1983 Volume 56 Issue 12 Pages 3600-3602
    Published: 1983
    Released: June 27, 2006
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    Complex-formation constants (KML+) of dibenzo-24-crown-8 (DB24C8) with alkali metal ions in acetonitrile and the solubility of DB24C8 in methanol, acetonitrile, and propylene carbonate were determined conductometrically and spectrophotometrically at 25 °C, respectively. The KML+ value sequences of the alkali metal ions with DB24C8 are Na+>Cs+>K+=Rb+. Dibenzo-24-crown-8 shows no remarkable selectivity for the alkali metal ions in acetonitrile. Transfer activity coefficients of the DB24C8 complexes with alkali metal ions were calculated from these data and literature values of transfer activity coefficients of alkali metal ions. For the same alkali metal ion, the bulky DB24C8-alkali metal ion complex is more soluble in the aprotic solvents acetonitrile and propylene carbonate than in the protic solvent methanol as compared with the case of the alkali metal ion itself. The transfer activity coefficient of the DB24C8-alkali metal ion complex from methanol to acetonitrile is somewhat sensitive to the variation of the alkali metal ion in the DB24C8 cavity, whereas the mobility of the DB24C8-alkali metal ion complex at the same concentration in the solvents is not sensitive.
  • Abdul Wasey, Raj K. Bansal, Masatada, Satake, Bal K. Puri
    1983 Volume 56 Issue 12 Pages 3603-3607
    Published: 1983
    Released: June 27, 2006
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    9,10-Phenanthrenequinone monoxime has been used as a reagent for the spectrophotometric determination of ruthenium(III) and rhodium(III) after extraction into molten naphthalene. The extracted mixture of the metal complex and naphthalene was dissolved in chloroform and ruthenium and rhodium were determined spectrophotometrically. Beer’s law holds in the concentration range of 0.2–4.1 μg/cm3 for ruthenium and 0.3–5.3 μg/cm3 for rhodium in 10 cm3 of the final solution. The molar absorptivities and Sandell sensitivities are calculated to be 9.70×103 l mol−1 cm−1 and 0.01 μg/cm2 (660 nm) for ruthenium and 1.13×104 l mol−1 cm−1 and 0.009 μg/cm2 (410 nm) for rhodium respectively. Aliquots containing 2.0 μg of ruthenium and 4.1 μg of rhodium give mean absorbances of 0.192 and 0.451 with standard deviations of 0.0017 and 0.0039, respectively. Interference of various ions has been studied and the method has been applied to the determination of ruthenium and rhodium in various synthetic mixtures. This procedure is also applied to the simultaneous determination of ruthenium and rhodium present together in a solution.
  • Yuki Fujii, Takemaru Kobayashi, Makoto Matsufuru, Sozo Takahashi
    1983 Volume 56 Issue 12 Pages 3608-3614
    Published: 1983
    Released: June 27, 2006
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    The kinetics for isomerization between ΔL2- and ΛL2-diastereoisomers of [Co(α-Me-sal2en)(L-aa)], where L-aa represents L-phe, L-met, L-ile, L-pro, N-Bz–L-ala, and N-Me–L-ala, were studied in methanol. The activation enthalpies (ΔH\ eweq/kJ mol−1) and the activation entropies (ΔS\ eweq/J K−1 mol−1) from the ΔL2-isomer (unstable form) to the ΛL2-isomer (stable form) were determined to be 86.6 and −9.6 for L-phe, 92.5 and +6.7 for L-met, 87.5 and −8.0 for L-ile, 100.4 and +28.0 for N-Bz-L-ala, and 102.9 and +18.4 for N-Me-L-ala, respectively. For L-procomplex, the ΔL2-isomer is the stable form, and the enthalpy and entropy for isomerization from ΛL2- to ΔL2- isomers were 96.2 and 0.0. The isomerization was catalyzed by acids but not by bases, and was much faster than the substitution of coordinated L-amino acid. The H–D exchange of N–H proton of N-Me–L-ala-complex proceeded with almost the same rate as the isomerization. The isomerization showed strong solvent dependency; it was fast in a hydrogen-bonding solvent, but was quite slow in a weak- or nonhydrogen-bonding solvent. On the basis of these facts, proton-assisted and/or hydrogen-bonding solvent-assisted intramolecular mechanism via an intermediate is proposed, in which the Schiff base takes a planar configuration and the amino acid coordinates as a unidentate ligand with its carboxylate group.
  • Tadashi Hara, Kaoru Fujinaga, Fujio Okui, Akihiro Arai
    1983 Volume 56 Issue 12 Pages 3615-3619
    Published: 1983
    Released: June 27, 2006
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    In order to confirm whether or not pyrolytic sulfurization gas chromatography can be applied to organophos-phorus compounds, many kinds of organophosphorus compounds were examined; C-rich compounds gave satisfactory results while C-poor ones gave lower oxygen values. The application limit of this method to various organophosphorus compounds was determined by the use of the C/O value and a structural factor for a sample, and the application limit was established. The structural factor of a sample varied with the kind of X1, X2, X3, and X4 in the general formula X1X2X3P=X4, where X1=OH, OR, R; X2=OH, OR′, R′; X3=OH, OR″, R″; and X4=O, S.
  • Sumio Kaizaki
    1983 Volume 56 Issue 12 Pages 3620-3624
    Published: 1983
    Released: June 27, 2006
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    The ligand field absorption and circular dichroism (CD) spectra were examined not only for trans-difluoro bis(diamine)chromium(III) complexes with two identical chiral diamines but also for nine new mixed diamine complexes of the same type with different diamines, which were ethylenediamine, trimethylenediamine, (R)- and (S)-propylenediamine, (1R, 2R)-1,2-cyclohexanediamine, (2R, 4R)- and (2R, 4R)-2,4-pentanediamine. The additivity of the CD contributions from the individual chiral diamines were substantiated for most of these complexes. On this basis, the conformational and the vicinal CD contribution due to puckered diamine rings and asymmetric carbon atoms, respectively, were differentiated, and the CD origins of all the present complexes were discussed in connection with stereochemistry.
  • Sumio Kaizaki
    1983 Volume 56 Issue 12 Pages 3625-3631
    Published: 1983
    Released: June 27, 2006
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    The circular dichroism (CD) spectra of optically active dinitritobis(diamine)chromium(III) complexes were measured in the visible and near-ultraviolet region, where the diamines used were ethylenediamine, trimethylenediamine, (R)-propylenediamine, (1R, 2R)-1,2-cyclohexanediamine, (2R, 4R)- and (2R, 4S)-2,4-pentanedianiine. The stereochemistry and the conformational (rotational) isomerism of coordinated nitrito ligands were discussed on the basis of the solvent-dependent CD spectra in the near-ultraviolet region of an intraligand absorption band localized on nitrito ligands. It is proposed that the CD variation in the intraligand transition region among the complexes concerned is responsible for the chiral arrangement of nitrito ligands. Further, the conformation of trimethylenediamine chelate in the trans-dinitrito-(R)-propylenediamine complex is determined to take a chair form in comparison with the CD behavior of the corresponding (2R, 4S)-2,4-pentanediainine complex.
  • Tsuyoshi Nomura, Genkichi Nakagawa
    1983 Volume 56 Issue 12 Pages 3632-3634
    Published: 1983
    Released: June 27, 2006
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    In order to determine reproducible and stable potential response conditions of the hydrogen ion in hydrofluoric acid solutions, lithium phosphate glass membranes of various constituents were developed. The glass membranes contained various metal oxides: Ag2O, Li2O, P2O5, MgO, BeO, WO2, and Al2O3. The response characteristics of the glass electrode depend strongly on the glass compositions. For the examination of the selectivity coefficient and the electrode function of hydrogen ion activities, the glass composition of 10 Ag2O : 20 Li2O : 50 P2O5 : 10 MgO : 10 WO2 is the most suitable one. The potential response is linear over the hydrogen ion activities of (100.3–10−4) mol/dm3, and has a slope of 44.5 mV/decade change in the hydrogen ion activity at 20 °C. The dynamic response time was within a minute in the range 10−1 to 10−4 mol/dm3. The intereference of the various cations on the activity of about 0.1 mol/dm3 can be ignored during the determination of the hydrogen ion activities at pH below 3. Physical and chemical properties, such as glass transition temperature, softening temperature, thermal expansion, membrane resistance, and chemical durability were measured and compared with those of other glasses.
  • Kazuhiko Ozutsumi, Hitoshi Ohtaki
    1983 Volume 56 Issue 12 Pages 3635-3641
    Published: 1983
    Released: June 27, 2006
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    The structures of mono(glycinato)nickel(II) and tris(glycinato)nickelate(II) complexes in aqueous solution were determined by the X-ray diffraction method. From the analysis of the radial distribution curve of solution A, in which the hexaaqua- and mono(glycinato)nickel(II) ions coexisted (the mole ratio Cgly/CNi=0.792, where Ci denotes the total concentration of species i), we found that the mono(glycinato)nickel(II) complex combined with four water molecules at the distance of (2.08±0.01) Å, the bond being longer than the Ni–OH2 bond (2.04 Å) within the [Ni(OH2)6]2+ ion. The Ni–O and Ni–N bond lengths within the mono(glycinato)nickel(II) complex were essentially the same and (2.09±0.02) Å. Therefore, the mono(glycinato)nickel(II) ion has a practically regular octahedral structure. The nonbonding Ni···C distance was also determined to be (2.87±0.02) Å. The X-ray scattering data of solutions having the Cgly/CNi mole ratio of 3.24 (solution B) and 3.94 (solution C), in both of which almost all nickel(II) ions formed the [Ni(gly)3] complex, showed that the tris(glycinato)nickelate(II) complex had a slightly distorted octahedral structure with the Ni–O and Ni–N bond lengths of (2.03±?.01) Å and (2.14±?.01) Å, respectively. The nonbonding Ni···C(COO), Ni···C(CH2) and Ni···O(O=C) distances were (2.82±?.02) Å, (2.96±?.02) Å, and (4.07±?.03) Å, respectively.
  • Yukito Murakami, Yoshio Hisaeda, Akiro Kajihara
    1983 Volume 56 Issue 12 Pages 3642-3646
    Published: 1983
    Released: June 27, 2006
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    Heptamethyl cobyrinate perchlorate, [Cob(II)ester]ClO4, was prepared in a good yield from cyanocobalamin. This hydrophobic complex is structurally comparable to the base-off form of vitamin B12r. Thermodynamic parameters (ΔG, ΔH, and ΔS) for axial ligation of [Cob(II)ester]ClO4 with various amines in dichloromethane and toluene were determined by electronic spectroscopy. The isoequilibrium temperatures obtained from plots of ΔH vs. ΔS were 194±20 and 317±20 K in dichloromethane and toluene, respectively. The equilibrium is primarily controlled by entropy at ordinary temperatures and the logK1 value varies sensitively along with the change in pKa of amine in dichloromethane, while the equilibrium values were almost invariant to the choice of amine in toluene because the measurements were carried out near the isoequilibrium temperature. The logK1 value for [Cob(II)ester]ClO4, different from the case of cobalt(II)-porphyrin complexes, depends on the nature of solvent used and undergoes wide variations. The possible functions of equatorial ligands involved in these two different complexes in the axial ligation behavior were discussed.
  • Michio Nakata, Norikazu Ueyama, Toshitsugu Terakawa, Akira Nakamura
    1983 Volume 56 Issue 12 Pages 3647-3651
    Published: 1983
    Released: June 27, 2006
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    Fe(III) complexes of cysteine-containing peptides such as Z–Cys–Pro–Leu–Cys–OMe and Z–Cys–Thr–Val–Cys–OMe corresponding to the Fe binding amino acid sequences in Cl. pasteurianum rubredoxin were prepared in solution and characterized by the absorption, circular dichroism (CD), and magnetic circular dichroism (MCD) spectra and were compared with those of the Fe(III) complexes of Z–Cys–Ala–Ala–Cys–OMe, Z–Ala–Cys–OMe, and Z–Cys–Ala–Cys–OMe. These model compelxes exhibited the existence of an electronic configuration and a core structure similar to that of native rubredoxin. The thermal stabilities of the Fe(III) pep tide complexes decrease in the following order, Z–Cys–Thr–Val–Cys–OMe>Z–Cys–Ala–Ala–Cys–OMe>Z–Cys–Pro–Leu–Cys–OMe\simeqZ–Ala–Cys–OMe>>Z–Cys–Ala–Cys–OMe.
  • Yoji Tachibana, Makoto Ando, Hiroyoshi Kuzuhara
    1983 Volume 56 Issue 12 Pages 3652-3656
    Published: 1983
    Released: June 27, 2006
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    Optically active α-deuterated α-amino acids were prepared in methano-d through Zn2+-catalyzed transamination reaction between the chiral pyridoxamine analogs, (R)- or (S)-15-aminomethyl-14-hydroxy-5,5-dimethyl-2,8-dithia[9] (2,5)pyridinophane and various α-keto acids with enantiomeric excesses ranging from 40 to 94%. Aliphatic α-keto acids gave α-deuterated α-amino acids, whereas aromatic ones possessing a methylene group between the carbonyl group (ketone) and the aromatic ring underwent concomitant deuterium substitution at the active methylene group to give the amino acids deuterated at both α- and β-positions of the carboxyl group. The use of the (S)-pyridoxamine analog gave the (R)-deuterated α-amino acids in excess and vice versa. The enatiomeric excesses of the amino acids were determined through the analyses of 1H NMR spectra of the Schiff bases produced by the condensation of the amino acids with the chiral pyridoxal analog, (R)- or (S)-15-formyl-14-hydroxy-2,8-dithia[9](2, 5)pyridinophane. The azomethine protons of the diastereomeric Schiff bases were clearly resolved in the spectrum and their intensities well reflected the amount of the diastereomers.
  • Takeo Shimidzu, Akira Murakami, Kazushige Yamana
    1983 Volume 56 Issue 12 Pages 3657-3660
    Published: 1983
    Released: June 27, 2006
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    A new type of cationic polynucleotide analog binding RNase A and its related compounds were synthesized from an insoluble cross-linked poly(4-vinylpyridine). The cross-linked poly(4-vinylpyridine) was converted into an aldehyde derivative by the reaction with cyanogen bromide. The aldehyde derivative was used for the binding of RNase A and 9-(2-aminoethyl)adenine through their amino groups. The cationic adenine polynuleotide analog binding RNase A favorably interacted with nucleotides containing uracil base through the base-specific interactions. This analog showed the considerable selectivity in the hydrolysis of uridine polynucleotide owing to the template effect.
  • Takayuki Suga, Takamitsu Yoshioka, Toshifumi Hirata, Tadashi Aoki
    1983 Volume 56 Issue 12 Pages 3661-3666
    Published: 1983
    Released: June 27, 2006
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    The full assignments of the 13C NMR signals of the herqueinone-type phenalenone, herqueinone, were established by a combination of the single-frequency off-resonance decoupling technique and the 13C-enrichment technique using the 13C-labeled tracer. Furthermore, the full assignments of the 13C NMR signals of deoxyherqueinone-type, dihydroherqueinone-type, and xanthoherqueinone-type phenalenone were completed on the basis of the application of the chemical shift rule and the mutual comparison of their chemical shifts.
  • Isao Ono, Norisuke Hata
    1983 Volume 56 Issue 12 Pages 3667-3671
    Published: 1983
    Released: June 27, 2006
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    2-(Dimethylcarbamoyl)quinolines are converted into 2-(methylaminoacetyl)quinolines (2) and 2-methyl-1H-pyrrolo[3,4-b]quinolin-3(2H)-ones (3) by irradiation in a nitrogen atmosphere. The reaction was quite efficient in acetonitrile but inefficient in hydrocarbon solvents and ethanol. The introduction of a chlorine atom to the 4-position of a quinoline nucleus caused an increase of the yield of 3 in company with a decrease of the yield of 2. On the other hand, irradiation in an oxygen atmosphere afforded 2-(methylcarbamoyl)quinolines as a main product but 2 and 3 were minor products. The results of quenching and sensitization experiments confirmed that the triplet π,π* state was responsible for the formation of those products. It is suggested that the reaction involves zwitterionic intermediates formed via Type II hydrogen abstraction by the ring nitrogen from the N-methyl group.
  • Masaki Amano, Motoshi Watanabe, Naomichi Baba, Jun’ichi Oda, Yuz ...
    1983 Volume 56 Issue 12 Pages 3672-3678
    Published: 1983
    Released: June 27, 2006
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    The present study deals with Mg-catalyzed asymmetric reduction of ethyl benzoylformate by the use of C2-symmetric NADH model compounds in which axial dissymmetry (chiral 1, 1′-binaphthyl derivatives) was introduced as a chiral source for the first time and the results were compared with those obtained by the corresponding C1-symmetric models bearing the same chiral center. Better e.e.’s of the reduction product were obtained by the use of NADH models having C2-symmetry than does the corresponding C1 symmetric ones. Further, the kind of bonding as well as the distance between chiral binaphthyl and the reaction center affected the stereochemical course of hydrogen transfer.
  • Tetsuo Nozoe, Hitoshi Takeshita, Kozo Tajiri
    1983 Volume 56 Issue 12 Pages 3679-3682
    Published: 1983
    Released: June 27, 2006
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    The sites of the nucleophilic attack of the base-catalyzed condensation of dimethyl malonate with 5-chloro-2-methoxytropone were solvent-dependent; the normal substitution product was predominant in benzene, but the ciné-substitution products were exclusive in methanol. With 2,5-dichlorotropone, the ciné-reaction products were exclusive in both solvents.
  • Masami Ishibashi, Takahiko Tsuyuki, Tatsushi Murae, Hiroshi Hirota, Ta ...
    1983 Volume 56 Issue 12 Pages 3683-3693
    Published: 1983
    Released: June 27, 2006
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    Two new quassinoids, shinjudilactone and shinjulactone C were isolated from the root bark of Ailanthus altissima SWINGLE and their structures were established to be 1β,11α-dihydroxy-2,16-dioxo-13(12→11α)abeo-picras-3-en-12,20-olide and 1α,12α : 5α,13α-dicyclo-1β,12β,20-trihydroxy-9βH-picras-3-ene-2,11,16-trione, respectively, by X-ray diffraction analysis. Shinjudilactone was prepared from ailanthone by benzilic acid rearrangement.
  • Hirokazu Naora, Masami Ishibashi, Tetsuo Furuno, Takahiko Tsuyuki, Tat ...
    1983 Volume 56 Issue 12 Pages 3694-3698
    Published: 1983
    Released: June 27, 2006
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    The structure of a new bitter principle, shinjulactone A, isolated from Ailanthus altissima SWINGLE was determined to be 11β,20-epoxy-1β,2α,11α,12α-tetrahydroxypicrasa-3,13(21)-dien-16-one and the configuration of a hydroxyl group at C-12 of ailanthone was revised to α-orientation by X-ray analysis.
  • Kazuki Sato, Tsutomu Higashijima, Rika Sugawara, Ukon Nagai
    1983 Volume 56 Issue 12 Pages 3699-3702
    Published: 1983
    Released: June 27, 2006
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    N-Acetyl-L-Leu–X–L-Pro–L-Val methylamides (IIa: X=D-Ala, IIb: X=Gly, IIc: X=L-Ala) were synthesized and subjected to CD and 1H NMR measurements to study the β-turn preferences of these peptides. Temperature dependences of L-Val4–NH proton chemical shifts in CD3OH solution were in the order of IIa<IIb<IIc, suggesting that the populations of the β-turn conformer with 4→1 hydrogen bonding were in the order of IIa>IIb>IIc. This order of β-turn preferences coincides with the order of the magnitudes of the Cotton effects in the CD spectra of the chromophoric derivatives, N-(2,4-dinitrophenyl)tetrapeptide p-nitroanilides, having the same sequences. This agreement supports the validity of the chiroptical method to study turn tendency of tetrapeptide sequences using chromophoric derivatives reported previously.
  • Noritaka Abe, Tarozaemon Nishiwaki, Hideko Yamamoto, Noboru Kunishige
    1983 Volume 56 Issue 12 Pages 3703-3714
    Published: 1983
    Released: June 27, 2006
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    Cyclohepta[4,5]pyrrolo[1,2-a]imidazoles (1,3a-diazacyclopent[a]azulenes) (2) and cyclohept[d]imidazo[1,2-a]imidazoles (1,3a,9-triazacyclopent[a]azulenes) (6) were synthesized from 2-aminocyclohepta[b]pyrroles and 2-aminocycloheptimidazole, respectively, in moderate to good yields. Reactions of 2 and 6 with reactive acetylenes gave 2-azacyclohepta[ef]cycl[3.2.2]azines together with bis(1,3a-diazacyclopent[a]azuleno)[1,7]diaza[12]annulenes (4) and 2,3-diazacyclohepta[ef]cycl[3.2.2]azines together with bis(1,3a,9-triazacyclopent[a]azuleno)[1,7]diaza[12]annulenes (8), respectively. Reactions of 2 and 6 with electron deficient olefins gave 4 and 8, respectively. These reactions proceeded regioselectively via 1,10-dipolar intermediates.
  • Ryozi Hino, Ryohei Matuura, Kenzi Toki
    1983 Volume 56 Issue 12 Pages 3715-3721
    Published: 1983
    Released: June 27, 2006
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    The crystallization mechanism for zeolite was investigated. Tetraethyl orthosilicate and silica sol were used as silica sources. Many kinds of solid phases were obtained at various reaction times. These solid phases were characterized by analyses for chemical compositions, X-ray diffraction, adsorption of nitrogen gas and water vapor, and IR spectroscopy. The results obtained suggest that the solid phase derived from tetraethyl orthosilicate at an early stage of reaction is composed of slightly ordered skeletons. In addition, during aging of gel at room temperature, the structure of the solid phase of gel undergoes a rearrangement to form a crystalline structure. On the other hand, the gel phase obtained from silica sol is predominantly made up by the coagulation of disordered aluminosilicate polymers or silicic polymers. These gel phases act as a precursor, and a part of the gel dissolved into the liquid phase and the dissolved species are converted into crystals in the liquid phase. Thus, the silica sources influence the structure of gel and crystals. In general, the crystallization mechanism is strongly influenced by the starting materials, especially by the silica sources.
  • Yukio Kurita, Hiroji Ohigashi
    1983 Volume 56 Issue 12 Pages 3722-3725
    Published: 1983
    Released: June 27, 2006
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    ESR spectra of single crystals of silver(I) nitrate–butanedinitrile(1/1) were measured at 77 K. Two paramagnetic centers, –CN···Ag2+···NC– and NO32−···Ag+, appeared simultaneously on X-irradiation at 77 K. The principal values of the g value (g) and the hyperfine coupling constants (A in the units of 10−1 cm−4) were g1=2.050, g2=2.053, and g3=2.302, A(Ag)1=21.8, A(Ag)2=22.0, A(Ag)3=34.9, A(N)1=15.3, A(N)2=15.9, and A(N)3=14.0 for the first center, and g⁄⁄=2.001, g=2.006, A(Ag)⁄⁄=20.3, A(Ag)=17.4, A(N)⁄⁄=59.4, and A(N)=32.8 for the second center. When the crystals X-irradiated at 77 K were exposed to visible light, the two centers disappeared simultaneously and the NO2 radicals increased. When the crystals X-irradiated at 77 K were warmed to room temperature, the first center changed to a new paramagnetic center, in which the unpaired electron coupled with a silver nucleus, two equivalent nitrogen nuclei, and a proton.
  • Toshio Yoshioka, Masaharu Shimamura
    1983 Volume 56 Issue 12 Pages 3726-3729
    Published: 1983
    Released: June 27, 2006
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    A polystyrene-based ion exchange fiber which has a large ion exchange capacity (ca. 2.5 mequiv g−1) and a high mechanical strength (ca. 1.4 g d−1) has first been prepared by using an islands-in-a-sea type composite fiber, the sea ingredient predominantly comprised of polystyrene for ion exchange and the island ingredient comprised of fiber-forming polypropylene for reinforcement, as the starting material; it can be used in an arbitrary form. It was found that the resulting fiber has two fundamental characteristics; the ion exchange rate for metal ions is extremely high, and the capacity of adsorbing the macromolecular ionic substance is exceedingly large, compared with ordinary ion exchange resins. The diffusion equation of ion exchange in the case of a cylindrical, endless fiber was solved by a modification of the method used for a spherical resin in a simple system. The former results are interpreted in terms of their solutions for two limiting cases. The latter results are explained by the fact that the surface-area ratio of the fiber to the resin is about ten.
  • Masayuki Nakagaki, Emiko Okamura, Shigeo Kubota
    1983 Volume 56 Issue 12 Pages 3730-3734
    Published: 1983
    Released: June 27, 2006
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    The penetration of water soluble polymers into lecithin monolayers was investigated for the random copolymers of L-lysine and L-leucine at various compositions in order to discuss the effect of hydrophobicity and charge density of the copolymers on their interaction with lipid monolayers. Compared to the penetration of the amino acids(L-lysine and L-leucine), the copolymer penetrated at very low concentration whereas the monomer (amino acid) did not. The amount of copolymer penetration increased significantly when the leucine fraction of a copolymer, XLeu, was larger than 0.3, while little penetration occurred when XLeu was smaller than 0.25. From these facts, it has been concluded that the penetration of lysine–leucine copolymers was not only attributed to the hydrophobicity or the charge density of copolymer molecules, but also to specific surface effects such as (1) the enhanced penetration of macromolecules by the preceded penetration of polymer segments of the same molecule, or (2) the formation of a compact α-helical structure as the result of the restricted motion of the segment near the lipid surface.
  • Yasushi Kai, Nobuko Kanehisa, Kunio Miki, Nobutami Kasai, Munetaka Aki ...
    1983 Volume 56 Issue 12 Pages 3735-3743
    Published: 1983
    Released: June 27, 2006
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    The s-trans-diene coordination in (η5-C5Me5)2Zr(butadiene) and the s-cis-diene coordination in (η5-C5Me5)2Zr(isoprene) were confirmed by the 1H- and 13C-NMR spectral studies. The reaction of 2,4-dimethyl-3-pentanone with these complexes occurred regio- and stereoselectively to give (Remark: Graphics omitted.) (5: R=H, 6: R=Me). The X-ray crystal structure analysis of 5 and 6 revealed the (Z)-configuration with respect to the olefin part. Crystal data for 5: monoclinic, space group P21/n with Z=4, a=11.650(2), b=17.791(3), c=13.612(2) Å, β=92.20(2)°, R=0.111 for 4308 non-zero reflections. Crystal data for 6: monoclinic, space group P21/n with Z=4, a=10.279(3), b=30.177(4), c=9.955(2) Å, β=108.67(2), R=0.104 for 3526 non-zero reflections.
  • Chikara Hongo, Ryuzo Yoshioka, Masanori Tohyama, Shigeki Yamada, Ichir ...
    1983 Volume 56 Issue 12 Pages 3744-3747
    Published: 1983
    Released: June 27, 2006
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    In connection with optical resolution of DL-amino acids, the racemization process of optically active amino acid salts was studied. A wide variety of salts of optically active amino acids with sulfonic acids or mineral acids could be racemized by heating in a medium of acetic acid at 80–100 °C for 1 h in the presence of 0.1 molar equivalents of an aldehyde and free DL-amino acid. From the reaction mixture, the racemized DL-amino acid salts were recovered in high yield (86–92%) and in high purity. An asymmetric transformation between two enantiomers of amino acid salt was attempted by the combination of preferential crystallization of the desired enantiomer and racemization of the antipode in the liquid phase. DL-Alanine p-chlorobenzenesulfonate was partially converted to L-isomer (yield 16%, optically purity 97%). Another approach was carried out by transformation between two diastereoisomeric salts. The combination of selective precipitation of less soluble diastereoisomeric salt and epimerization of soluble diastereoisomeric salt allowed DL-phenylglycine d-camphor-10-sulfonate to be partially converted to D-phenylglycine d-camphor-10-sulfonate (yield 68%, optical purity 96%).
  • Nobuaki Washida, Hiroshi Bandow, Gen Inoue
    1983 Volume 56 Issue 12 Pages 3748-3755
    Published: 1983
    Released: June 27, 2006
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    Chemiluminescences produced in the reaction of CO with active nitrogen were measured in the region from infrared to vacuum ultraviolet. The infrared emission from vibrationally excited CO was measured by means of a FTIR spectrometer. A vibrationally excited CO up to v″=18 was observed. The quenching and relaxation of vibrationally excited CO were measured by the addition of other gasses. The formation of carbon atoms was observed by the absorption of carbon resonance lines, and the recombination reaction of C+N+M→CN*+M is proposed as the mechanism of the violet and red emission of CN. The reaction of CO*(a3Π)+CO\ eweq→C+CO2 is proposed as the carbon-atom source. The emission of the fourth positive band of CO was observed in the vacuum UV region. The effect of self-absorption by the vibrationally excited CO was reduced by the addition of CO2. It is suggested that the apparent abnormal vibrational distribution in CO(A1Π) can be reduced by considering the effect of the quenching of CO(A1Π).
  • Etsuro Kobayashi
    1983 Volume 56 Issue 12 Pages 3756-3760
    Published: 1983
    Released: June 27, 2006
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    The conditions for the synthesis of γ-NH4ZrH(PO4)2 and the ion-exchange properties of γ-Zr(HPO4)2·2H2O were investigated. The influence of the mole ratio of MH2PO4 (M=Na, K, and NH4) to ZrOCl2 on the formation of γ-zirconium phosphate using NaH2PO4 as MH2PO4 was such that the γ-form was obtained not in the NaH2PO4/ZrOCl2 mole ratio of 4, but in are of 8.3 or more. In case of the Na or K salt, a non-stoichiometric compound, MxZrH2−x(PO4)2, was obtained. When using the NH4 salt, a stoichiometric compound was synthesized at 120–280 °C in accordance with the following equation: ZrOCl2+NH4H2PO4→NH4ZrH(PO4)2+NH4Cl+HCl+H2O. Using an autoclave lined with Hastelloy-B and equipped with a stirrer, the synthesis was carried out by a reaction at 150–160 °C for 18–54 h. γ-Zr(HPO4)2·2H2O was prepared from NH4ZrH(PO4)2, and its ion-exchange capacity at pH 4.5 and selectivity quotient toward alkali metals and ammonium ions were measured. The measured values increased in the order of Li+<Cs+<Na+<K+<NH4+.
  • Mitsuyoshi Ichihashi, Hisanobu Wakita, Isao Masuda
    1983 Volume 56 Issue 12 Pages 3761-3764
    Published: 1983
    Released: June 27, 2006
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    The structures of the solute complexes existing in methanolic CuCl2 solutions with concentrations of 1.055–3.250 mol dm−3 were investigated by X-ray diffraction analysis. The solute complexes which were predominantly present could be formulated as [CuCln(CH3OH)6–n] (n=1–3); they have an axially elongated octahedral structure including Cl at the equatorial site. The Cu-O bond distance was 2.230–2.238 Å. Methanol molecules were coordinated at the equatorial site with the Cu-O bond distance of 1.926–1.950 Å and at the axial site with that of 2.423–2.473 Å. When the initial concentration of CuCl2 was kept within the range examined here, almost all of the Cu2+ ions formed chloro complexes.
  • Yoshitsugu Hasegawa, Giichi Yamamine
    1983 Volume 56 Issue 12 Pages 3765-3768
    Published: 1983
    Released: June 27, 2006
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    The tetraammineplatinum(II)–hydrogen-ion exchange on α-zirconium phosphate has been investigated. The ion-exchange process was examined by measuring the change in the pH values of the supernatants. α-Zirconium phosphate loaded with tetraammineplatinum(II) was characterized by means of chemical analysis, X-ray diffractometry, infrared spectroscopy, and thermal analysis. The ion-exchange reaction proceeded more easily than the hexaaminecobalt(III)–hydrogen-ion exchange, and about 50% of the hydrogen ions in α-zirconium phosphate were replaced by tetraammineplatinum(II). The interlayer distance of the exchanger expanded from 7.60 to 10.7 Å.
  • Genichiro Kura
    1983 Volume 56 Issue 12 Pages 3769-3772
    Published: 1983
    Released: June 27, 2006
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    The hydrolysis rate of inorganic cyclo-hexa- and cyclo-octaphosphate in 0.1 mol dm−3 HCl was determined by means of anion-exchange chromatography. The phosphorus content in the column effluent was determined automatically by the use of the MoV–MoVI reagent. The hydrolysis reactions were first-order. The rate constant decreases from cyclo- tri- to cyclo-hexaphosphate with the increased ring, however, that of cyclo-octaphosphate increases again. This increase is thought to be due to the stronger proton affinity of cyclo-octaphosphate. The Arrhenius activation energies for cyclo-hexa- and cyclo-octaphosphate hydrolysis were 91.5 and 96.9 kJ mol−1 respectively.
  • Tokunaru Horie, Hiroki Kourai, Nobuhisa Fujita
    1983 Volume 56 Issue 12 Pages 3773-3780
    Published: 1983
    Released: June 27, 2006
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    The demethylation of seven 8-hydroxy-5,7-dimethoxyflavones with anhydrous aluminum chloride or bromide in acetonitrile was studied and the following results were obtained. (1) Anhydrous aluminum chloride in acetonitrile selectively split the 5-methoxyl group without cleavage of the 7-methoxyl group, and seven 5,8-dihydroxy-7-methoxy-flavones were quantitatively synthesized by the demethylation. (2) In the demethylation with anhydrous aluminum bromide, the 5- and 7-methoxyl groups on 4′,5,7-trimethoxy- and 3′,4′,5,7-tetramethoxy-8-hydroxyflavone were selectively split to give the corresponding 5,7,8-trihydroxyflavones in good yield. However, the demethylation was not accessible to the synthesis of 5,7,8-trihydroxy-3′,4′,5′-trimethoxyflavone, 4′,5,7,8-tetrahydroxy-3′-methoxy-, and 3′,5,7,8-tetrahydroxy-4′-methoxyflavone, because of the cleavage of the methoxyl groups on the B ring. The synthesized flavones were employed for the identification of the two natural flavones, which were proposed to be 4′,5,8-trihydroxy-7-methoxyflavone and 4′,5,8-trihydroxy-3′,7-dimethoxyflavone. The former, salvitin, was revised to 4′,5,7-trihydroxy-6-methoxyflavone and the latter seemed to be 4′,5,7-trihydroxy-3′,8-dimethoxyflavone.
  • Setsuko Ando, Hideo Takiguchi, Nobuo Izumiya
    1983 Volume 56 Issue 12 Pages 3781-3785
    Published: 1983
    Released: June 27, 2006
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    Three cyclic tetradecapeptides related to gramicidin S (GS): cyclo(–Leu–Orn–Leu–Orn–Leu–D-Phe–Pro-)2, cyclo(–Leu–Orn–Leu–Orn–Leu–D-Phe–Sar–)2, and cyclo(–Leu–Orn–Leu–Orn–Leu–D-Phe–Gly–)2, were synthesized to investigate the contributions of the ring size of cyclic peptides and of the number of the basic amino acid residues to the antibacterial activity. The protected cyclic tetradecapeptides were synthesized through a cyclization reaction of the linear tetradecapeptide azide in pyridine. Hydrogenolysis of the protected cyclic peptides afforded crystalline tetrahydrochlorides of the analogs. The homogeneity of the analogs was ascertained by TLC, paper electrophoresis, and elemental analysis. In the experiment of circular dichroism, the two analogs with 7,7′-Pro or 7,7′-Sar gave spectra similar in shape to that of GS, while the analog with 7,7′-Sar gave a slightly different spectrum from that of GS. The antibacterial assays showed that the analog with 7,7′-Pro exhibited considerable activities against the microorganisms tested, particularly against Gram-negative bacterias such as Escherichia coli and Shigella sonnei. On the other hand, the analogs with 7,7′-Sar or 7,7′-Gly exhibited weaker activities than that of GS.
  • Akihide Kitamura, Hiroharu Tanikawa, Kunio Oohashi, Hirochika Sakuragi ...
    1983 Volume 56 Issue 12 Pages 3786-3790
    Published: 1983
    Released: June 27, 2006
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    Bis(2-phenylbenzoyl) peroxide (2-PhBPO) was found to decompose on singlet and triplet sensitized irradiations in benzene and carbon tetrachloride. The quantum yields were determined to be 0.48 and 0.43 on direct excitation and chrysene sensitization in benzene, respectively, and 0.62 and 0.60 on benzophenone and 3′-methoxyacetophenone sensitizations in carbon tetrachloride, respectively. The reaction mechanisms are discussed from the standpoint of the modes of bond cleavage.
  • Kazuhiko Takai, Koichiro Oshima, Hitosi Nozaki
    1983 Volume 56 Issue 12 Pages 3791-3795
    Published: 1983
    Released: June 27, 2006
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    Treatment of a solution of geraniol and (t-BuO)3Al in benzene with t-BuOOH at 5 °C gives (2R*, 3R*)-2,3-epoxy-3,7-dimethyl-6-octenyl acetate in 83% yield after acetylative workup. Eight allylic alcohols are converted to α,β-epoxy alcohols in preparative yields. The epoxidation of secondary (E)-allylic alcohols shows opposite stereoselectivities to t-BuOOH–VO(acac)2 system. Asymmetric epoxidation with a chiral hydroxamic acid as a ligand gives unsatisfactory degrees of enantiomeric excess. The same system can also convert secondary alcohols into ketones in excellent yields, while primary ones react very slowly.
  • Kazumi Hirota, Mitsuru Igarashi, Yoshio Inoue, Riichirô Chû ...
    1983 Volume 56 Issue 12 Pages 3796-3801
    Published: 1983
    Released: June 27, 2006
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    The effects of basic amino acid residues on the base stacking of nucleotides have been studied to clarify the nature of interaction between histones and DNA′s. For this purpose, lysine and arginine derivatives were used as models for basic amino acid residues in histone. The base stacking association of 2′-deoxyguanosine 5′-monophosphate(5′-dGMP) in aqueous solution has been studied by the measurement of the concentration dependence of 1H NMR chemical shifts of 5′-dGMP both in the absence and in the presence of the basic amino acid derivatives at different pH’s. We clarified that the lysine favors the base stacking association of 5′-dGMP through the interaction with the phosphate group(s), while an excess of the arginine destabilizes the stacking aggregates through the interaction with the base moiety. We also clarified that the ionization of the phosphate group destabilizes the stacking association of 5′-dGMP both in the absence and in the presence of the basic amino acids.
  • Shigeru Oae, Hideo Togo
    1983 Volume 56 Issue 12 Pages 3802-3812
    Published: 1983
    Released: June 27, 2006
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    Arenesulfonic acids, their sodium salts, and alkyl arenesulfonates can be reduced readily to the corresponding arenethiols quantitatively by treatment with a mixture of triphenylphosphine and a catalytic amount of iodine, while alkanesulfonic acids, sulfinic acids, disulfides, thiosulfonic testers, and sulfonates are also readily reduced to the corresponding thiols similarly. Upon treatment with a mixture of triphenylphosphine and excess iodine, however, these aliphatic sulfur compounds are converted eventually to the corresponding alkyl iodides. The relative reactivities of these sulfonyl derivatives in the reaction with the triphenylphosphine–iodine system are the following. Aromatic series: ArSO2Cl, ArSO2SAr′>ArSO2H>ArSO3R>ArSO3HNBu3+ (or PyH+)>ArSO3H>ArSO2SO2Ar>>ArSO2CH2C(CH3)3, ArSO3Ar′. Aliphatic series: RSO2Cl, RSO2SR′, RSO2HNBu3+>RSO3HNBu3+>RSSR, RSO2H>RSO3H>RSH>RSO3R′. In these reactions, the arenesulfonic acids bearing electron-donating substituents can be reduced more readily than those having electron-withdrawing substituents.
  • Shigeru Oae, Hideo Togo
    1983 Volume 56 Issue 12 Pages 3813-3817
    Published: 1983
    Released: June 27, 2006
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    Organic sulfonic acids, sodium sulfonates, and alkyl sulfonates were readily reduced to the corresponding disulfides in moderate yields upon treatment with a mixture of a polyphosphoric acid derivative and iodide. In these reactions, formation of mixed anhydrides each having a P–O–S linkage is the key step, and subsequent attack of iodide on the sulfur atom gives the corresponding sulfonyl iodides which are reduced further exothermally to the disulfides with hydrogen iodide. Actually, p-toluenesulfonyl chloride was isolated in the reaction of p-toluenesulfonic acid and polyphosphoric acid derivatives with chloride ion. The competitive reduction of various aromatic sulfonic acids reveals that an aromatic sulfonic acid bearing an electron-donating para-substituent is more readily reduced to the disulfide than that which has an electron-withdrawing para-substituent.
  • Shigeru Oae, Hideo Togo
    1983 Volume 56 Issue 12 Pages 3818-3823
    Published: 1983
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    Sulfuric acid and sodium sulfate were readily reduced to elemental sulfur and hydrogen sulfide upon treatment with a mixture of either one of polyphosphoric acid derivatives, PPE, PPA, and P4O10, which can form a mixed anhydride having –P–O–S– linkage, and iodide or thiol. Sulfur dioxide, which is undoubtedly one of important intermediates, was trapped by p-tolyllithium to afford p-toluenesulfinic acid which was converted to p-tolyl methyl sulfone upon treatment with methyl iodide, though the yield was low. Sulfur trioxide which has been postulated as the key intermediate in the biological reduction of inorganic sulfate, was also trapped by mesitylene to give mesitylenesulfonic acid in a high yield. The reduction of sulfate to elemental sulfur and hydrogen sulfide is considered to proceed through the course which resembles the biological reaction path involved in the assimilatory metabolism of inorganic sulfate in microorganisms and plants.
  • Minoru Suzuki, Makoto Segawa, Teruaki Suzuki, Etsuro Kurosawa
    1983 Volume 56 Issue 12 Pages 3824-3826
    Published: 1983
    Released: June 27, 2006
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    Three halogenated chamigrane-type sesquiterpenes have been isolated as the minor metabolites from the red alga Laurencia nipponica, collected at Sannai, near Wakkanai. The absolute structures of these compounds were confirmed by spectral and chemical methods.
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