Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
Volume 55 , Issue 11
Showing 1-50 articles out of 83 articles from the selected issue
  • Katsuyoshi Kamakura
    1982 Volume 55 Issue 11 Pages 3353-3355
    Published: 1982
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    A method for determining diffusion coefficients of electrolytes was studied by the use of a conductance cell made of a Pyrex glass tube (4–7 cm in diameter and 6.5 cm in length). A pair of platinized platinum electrodes are sealed into the tube at a position 10 mm below the top of the glass tube. The diffusion was carried out from solution in the cell to an outer solvent, and the rate was measured from the decrease in conductance at a fixed position in the cell. In the graphical relation between the measured diffusion coefficient and the time, the differential diffusion coefficient at the initial concentration of the diffusing solution was estimated by extrapolation of the linear portion of the plot to time→0. The differential diffusion coefficients obtained in 0.1 mol dm−3 solutions at 25 °C were as follows: HCl, (3.12±0.08)×10−5; KI, (1.909±0.020)×10−5; NaCl, (1.520±0.016)×10−5; 1/2Na2SO4, (1.059±0.028)×10−5; CuSO4, (0.610±0.033)×10−5 cm2 s−1.
  • Ping-Lin Kuo, Isao Ikeda, Mitsuo Okahara
    1982 Volume 55 Issue 11 Pages 3356-3359
    Published: 1982
    Released: June 27, 2006
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    The hydrophilicity of surface-active crown compounds and their change upon the addition of electrolytes were investigated by measuring the phase-inversion temperature (PIT), the phenol index, and the cloud point. Sodium chloride and potassium chloride were observed to raise the hydrophilicity of 15-crowns and 18-crowns respectively, in contrast with their lowering effect on the hydrophilicity of usual poly(oxyethylene)-type nonionics. The effective HLBs of dodecyl crown ethers, estimated from both the PIT and the phenol index, were compared with those of poly(oxyethylene) dodecyl ethers, and the hydrophilicity of the crown rings were discussed in conjunction with that of the poly(oxyethylene) chain.
  • Osami Tozawa, Danji Nomura
    1982 Volume 55 Issue 11 Pages 3360-3367
    Published: 1982
    Released: June 27, 2006
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    Taft’s polar and steric parameters, Σσ*, ΣEs, and nonpolar parameter, ΣS* governing the reverse osmosis of nonionized polar aliphatic and alicyclic organic compounds using a cellulose acetate membrane were also applicable to aliphatic monoamino monocarboxylic acids having zwitter ion structure. These three parameters were further extended so as to include the cases of sulfur-containing amino acids, hydroxy-substituted, and aromatic type amino acids. Reverse osmosis of monoamino monocarboxylic acids in binary aqueous solution systems containing L-alanine was carried out. As a result, added amino acids were adsorbed by the membrane when added in low concentration (<0.001 mol dm−3), and the permeation of L-alanine was governed by the difference of Taft’s polar parameter between L-alanine and the added amino acid. Reverse osmosis of monoamino dicarboxylic acids indicated that hydrogen ions were adsorbed by the membrane, and the adsorption isotherms of hydrogen ions were approximately represented by the Langmuir formula for each amino acid. The electrostatic repulsion between R ionic species in monoamino dicarboxylic acid and the negatively dissociated groups of the membrane was weakened by neutralization of the membrane by hydrogen ion adsorption, resulting in decreased amino acid rejection. It was noted that the ultraviolet spectrum and the titration curve of permeate of amino acids were different from those of the feed solution; relationship between this phenomenon and adsorption of hydrogen ions was investigated.
  • Tadashi Kato, Tsunetake Fujiyama, Hiroyasu Nomura
    1982 Volume 55 Issue 11 Pages 3368-3372
    Published: 1982
    Released: June 27, 2006
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    A concentration fluctuation value obtained from Rayleigh scattering intensity was confirmed to give a thermodynamic quantity of an equilibrium system. An observation of concentration fluctuation by a light scattering method was found to be the most direct and useful way of determining a concentration derivative of a chemical potential. For methanol, ethanol, and 1-propanol–carbon tetrachloride systems, the Kirkwood-Buff parameters, G11, G22, and G12, were determined by the use of concentration fluctuation data. The structure of these systems was discussed on the basis of the calculated Kirkwood-Buff parameters.
  • Yasuhisa Maeda, Akira Fujishima, Kenichi Honda
    1982 Volume 55 Issue 11 Pages 3373-3376
    Published: 1982
    Released: June 27, 2006
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    The energy efficiency of a polycrystalline ZnO photoanode in an electrolyte solution containing redox agents was investigated by measuring the temperature change of the electrode surface. The results of photothermal measurements show that the energy efficiency depends on the kind of redox agents used. Reducing agents with more positive potentials gave larger energy efficiencies, but the potential must be negative enough to decrease ZnO dissolution.
  • Susumu Matsuzaki, Tetsuya Mitsuishi, Koichi Toyoda
    1982 Volume 55 Issue 11 Pages 3377-3380
    Published: 1982
    Released: June 27, 2006
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    Resonance Raman spectra of chloranil anion radical dimers were measured in ethanol at 140 K by an exciting radiation within the CT band, and all the Raman lines observed were shown to be totally symmetric. Two strong Raman lines at 114 cm−1 and 168 cm−1 have been assigned to inter-radical stretching vibrations of the dimer. The relative intensity of these lines changed depending on the counter ion species. Formation of two dimers has been supposed to explain the spectral behavior. Influence of 18-crown-6 on the spectra was investigated. The result strongly suggests that one dimer gives two inter-radical Raman lines. Two interpretations are proposed for the simultaneous resonance enhancement of these Raman lines: mechanical coupling of the inter- and intra-radical vibrations or distorsion of the D2h eclipsed dimer structure. Other five lines at higher frequencies have been assigned to intra-radical vibrations of the dimer.
  • Masayuki Nakagaki, Emiko Okamura
    1982 Volume 55 Issue 11 Pages 3381-3385
    Published: 1982
    Released: June 27, 2006
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    The surface pressure of the monolayers of dimyristoyl phosphatidylcholine(DMPC) on leucine and norleucine solutions was measured and the amounts of these amino acids which had penetrated into the DMPC monolayer were calculated by means of a successive approximation. Although the amounts of leucine and norleucine adsorbed onto the solution surface were nearly equal and were larger than that of lysine, the amount of leucine which had penetrated into the DMPC monolayer was remarkably small. That of norleucine was not so small, but was still smaller than that of lysine except for the region where the molecular area of DMPC is large. The partial molecular areas of amino acid, \barA2, and DMPC, \barA3, were calculated in each case. The value of \barA2, was the largest in the case of leucine and the smallest in the case of lysine, which means that the area occupied by lysine is smaller than that of norleucine because the interaction of ε-amino group with DMPC contracts the mixed monolayer. The change in the value of \barA3 due to the interaction with amino acid, however, was not large, which means that the change in the state of DMPC itself is not large and rather independent of the kind of amino acid.
  • Kazuaki Harata, Kaneto Uekama, Masaki Otagiri, Fumitoshi Hirayama, Yuk ...
    1982 Volume 55 Issue 11 Pages 3386-3389
    Published: 1982
    Released: June 27, 2006
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    The crystal structure of the hexakis(2,3,6-tri-O-methyl)-α-cyclodextrin (abbreviated to methyl-α-CDx)–benzaldehyde (1:1) complex, C54H96O30·C7H6O, was investigated by the X-ray method. The crystal is monoclinic with the space group P21 and Z=2; the cell dimensions are a=11.604(1), b=23.832(3), c=13.539(1) Å, and β=106.11(1)°. The structure was determined by inspection of a Patterson map and a trial-and-error method combined with the rigid-body least-squares technique, and refined by the block-diagonal least-squares method to the final R-value of 0.10 for 3597 reflections (sinθ⁄λ≤0.49). The methyl-α-CDx molecule is in the shape of a distorted and truncated hexagonal cone. The guest benzaldehyde molecule is fully included within the host cavity. The carbonyl group is located at the center of the cavity, while the phenyl group is located at the baseside of the host cone. Methyl-α-CDx molecules, of which pseudo hexagonal axis is inclined by an angle of 17.0° against the crystallographic a axis, are stacked along the a axis to form a head-to-tail channel-type structure.
  • Yoshihiro Nakato, Akira Tsumura, Hiroshi Tsubomura
    1982 Volume 55 Issue 11 Pages 3390-3393
    Published: 1982
    Released: June 27, 2006
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    Electroluminescence spectra of an n-type gallium phosphide (n-GaP) electrode caused in the presence of oxidants such as [Fe(CN)6]3− and S2O82− were measured as functions of the electrode potential, the solution pH, and the kind of crystal faces. The electroluminescence spectra consisted of two bands; one was assigned to arise from electronic transitions in the bulk and the other from those at the surface. It was found that the position and the spectral shape of the luminescence band arising from the surface were quite independent of various experimental conditions, while its intensity was strongly dependent on them. These results were explained well by the view that the luminescence band is caused by “surface-trapped holes” acting as a precursor of anodic dissolution reaction of the electrode, as proposed previously. The physicochemical model of the surface-trapped hole was discussed on the basis of the above results.
  • Shozo Furuyama, Michio Sawada, Kinji Hachiya, Tetsuo Morimoto
    1982 Volume 55 Issue 11 Pages 3394-3397
    Published: 1982
    Released: June 27, 2006
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    The asymmetric adsorption of the racemic alanine by the optically active quartz from ethanol solution at 8 °C was studied by the 14C-tracer method and the newly developed 14C-tracer·ninhydrin-colorimetry combination method. The preferential adsorption of L-alanine by levorotatory quartz (l-quartz) and D-alanine by dextrorotatory quartz (d-quartz) was confirmed. The asymmetric adsorptivity (As) falls in the range of 1.1–1.3, which is comparable with the value determined at −80 °C in the previous paper. The effects of water content in the ethanol solution and of the adsorption temperature upon the adsorption affinity of alanine to quartz were also measured. The cause for the asymmetric adsorption is discussed from the crystallographic point of view.
  • Akio Furusaki, Chuji Katayama, Takeshi Matsumoto, Minoru Suzuki, Terua ...
    1982 Volume 55 Issue 11 Pages 3398-3402
    Published: 1982
    Released: June 27, 2006
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    The molecular structure of 7,8-epoxyhalochamigrene, C15H23OBr2Cl, has been confirmed by means of X-ray crystallographic analysis. The crystals are orthorhombic, with sixteen molecules in a unit cell with dimensions of a=10.303, b=71.31, and c=9.061 Å; the space group is P212121. 4241 independent intensity data were collected on a four-circle diffractometer with graphite-monochromated Cu Kα radiation. The structure was solved by the Monte Carlo direct method, using 20 reflections as a starting set, and was refined by the block-diagonal least-squares method. The final R value was 0.072. The molecular structure thus obtained corresponds to that proposed by Howard and Fenical on the basis of chemical and spectroscopic evidence. The four crystallographically-independent molecules have almost the same geometries. Of the two spiro-linked six-membered rings, the one having the epoxy group takes a half-chair conformation, while the other adopts a chair conformation. The crystal consists of alternating single and triple molecular layers parallel to the (010) plane; the latter layer has a molecular arrangement approximately of P212121 symmetry.
  • Teruyo Yamashita, Hiroshige Yano, Shoji Harada, Tatsuya Yasunaga
    1982 Volume 55 Issue 11 Pages 3403-3406
    Published: 1982
    Released: June 27, 2006
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    Ultrasonic absorption was measured in hexane solutions of octylammonium alkanoates (nonanoate, decanoate, dodecanoate, and tetradecanoate). The value of critical micelle concentration (CMC) was determined to be 0.02 M (1 M=1 mol dm−3) for all the surfactants. The excess ultrasonic absorption, observed in the solutions above the CMC, was ascribed to the association-dissociation of the monomer to and from the micelle. From the concentration dependences of the ultrasonic parameters, the mean aggregation number of the micelle, the rate constants, and the enthalpy change of the above reaction were obtained. These results were discussed in relation to the shape of the reversed micelle and the solute-solvent interactions.
  • Hiroshi Hiratsuka, Hitoshi Nakamura, Yoshie Tanizaki, Keihachiro Nakaj ...
    1982 Volume 55 Issue 11 Pages 3407-3412
    Published: 1982
    Released: June 27, 2006
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    Radical ions of some 9-substituted anthracene derivatives have been prepared in polymer film by γ-irradiation at 77 K. By use of the polarized absorption spectra of these radical ions, the absorption spectra have been resolved into two components (resolved spectra), the transition moments of which are polarized parallel to the molecular long and short axes, respectively. Correlation of the characteristic absorption bands is discussed briefly.
  • Ryuichi Yamada, Kiyoshi Tamura, Shoji Harada, Tatsuya Yasunaga
    1982 Volume 55 Issue 11 Pages 3413-3416
    Published: 1982
    Released: June 27, 2006
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    Concentration-jump kinetic studies of the aqueous poly(acrylic acid)–copper(II) system reveal the presence of a relaxation phenomenon in the time range of 102 ms. Kinetic data under various pH’s and compositions, together with the potentiometric results, indicate that this relaxation effect is due to the following complex-formation reaction:
    CuL2+L22−\oversetk2\undersetk−2\ ightleftharpoonsCu(L2)22−,
    where L22− is a coordination unit consisting of two adjacent carboxylato side groups on the polymer chain. The specific features of the pH dependence of the τ−1 value are discussed in relation to the degree of dissociation of the carboxyl groups. The rate and stability constants of the reaction are determined to be: k2=5.6×103 M−1 s−1 (1 M=1 mol dm−3), k−2=0.7 s−1, and K2 (=k2k−2)=7.9×103, at pH 7.0, I≈0, and 25 °C. The overall complex-formation mechanism, involving the very rapid formation of CuL2, is discussed.
  • Takashi Kawamura, Sachio Enoki, Shigeru Hayashida, Teijiro Yonezawa
    1982 Volume 55 Issue 11 Pages 3417-3421
    Published: 1982
    Released: June 27, 2006
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    The anion radical of V2(CO)8(μ-PPh2)2 and the cation radical of Mn2(CO)8(μ-AsPh2)2 are generated by chemical reduction of the vanadium complex with LiBHEt3 or potassium naphthalenide and by radiochemical oxidation of the manganese complex in frozen Freon mixture, respectively. Their anisotropic ESR spectra show that the V2P2 and the Mn2As2 rhomboids are planar. Their g and hyperfine splitting tensors are analyzed on the basis of a qualitative molecular orbital scheme for metal-metal bonds developed from a hypothesis that metal-ligand interactions are larger than metal-metal interactions. The odd electron orbital of V2(CO)8(μ-PPh2)2−· is assigned to the metal-metal π* MO and the odd electron density on the vanadium d AO is estimated as 0.21. The odd electron of Mn2(CO)8(μ-AsPh2)2 is concluded to be accomodated in the metal-metal σ* MO and odd electron densities on manganese and arsenic atoms are evaluated as ρ(Mn d)=0.25 and ρ(As p)=0.08 or 0.16, respectively. Order of magnitude estimates of orbital energy differences between metal-metal MO’s are obtained from analyses of g tensors as ε(π*)−ε(σ)\simeq0.4 and ε(π*)−ε(δ)\simeq0.9 eV for the anionic divanadium complex and ε(σ*)−ε(δ*)\simeq1.1 and ε(σ*)−ε(π)\simeq1.4 eV for the cationic dimanganese complex.
  • Jun-ichi Murakami, Katsuhiko Okuyama, Mitsuo Ito
    1982 Volume 55 Issue 11 Pages 3422-3423
    Published: 1982
    Released: June 27, 2006
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    The one-photon absorption spectrum of p-terphenyl vapor was observed in a supersonic free jet by using multiphoton ionization spectroscopy. In the spectrum were observed the progressions of the in-phase and out-of-phase torsional vibrations of the benzene rings. It was concluded that p-terphenyl has a planar structure in the first excited singlet state, whereas it is twisted in the ground state.
  • Shoji Fujisawa, Isao Oonishi, Junji Aoki, Yuji Ohashi, Yoshio Sasada
    1982 Volume 55 Issue 11 Pages 3424-3428
    Published: 1982
    Released: June 27, 2006
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    The crystal structure of the title compound, C38H18, has been determined by X-ray analysis. The space group is Pa, with unit cell dimensions a=31.276(4), b=3.7818(4), c=21.663(3) Å, β=124.22(1)° and Z=4. The structure was solved by the direct method and refined by full-matrix least-squares methods to an R value of 0.073 for 2619 reflections. Two crystallographically independent molecules are largely distorted from a planar structure due to the repulsions between the crowded hydrogen atoms, with different conformations to each other. The molecules are stacked face-to-face by van der Waals forces to form column structures along the b axis.
  • Yukishige Kitano, Tetsuya Kato, Hisao Kondo, Tamaichi Ashida
    1982 Volume 55 Issue 11 Pages 3429-3433
    Published: 1982
    Released: June 27, 2006
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    The relative configuration of natural 3,6-epoxy-5-hydroxy-5,6-dihydro-β-ionol, C13H22O3, a principal tobacco constituent, has been established by an X-ray crystal structure analysis of its p-nitrobenzoate, C20H25NO6, as (±)-(1R,2R,5S)-2,5-epoxy-2-[(1E,3S)-3-hydroxy-1-butenyl]-1,3,3-trimethyl-1-cyclohexanol. The derivative crystallizes in space group P\bar1 with a=11.618(1), b=12.373(2), c=7.934(1) Å, α=108.43(1), β=108.89(1), γ=95.95(1)° and Z=2. The crystal structure was solved by the direct phasing method and refined by the blockdiagonal least-squares method to the final R index of 0.073 for 2550 reflections. The hydrogen bondings linking the two molecules placed in pairs around a crystallographic center of symmetry are disordered over two sites in the crystal.
  • Masayuki Aizawa, Tsuyoshi Komatsu, Tsurutaro Nakagawa
    1982 Volume 55 Issue 11 Pages 3434-3437
    Published: 1982
    Released: June 27, 2006
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    ESR measurements of Mn2+ ions in aqueous manganese dodecyl sulfate (Mn(DS)2) solutions with or without 0.05% poly(N-vinylpyrrolidone)(PVP) were carried out at 30 °C. The dependences of linewidths and of absorption intensities on the Mn(DS)2 concentration in (Mn(DS)2+0.05% PVP) solutions changed abruptly at a concentration where a PVP–Mn(DS)2 complex begins to form. The same dependence in Mn(DS)2 solutions was found around the CMC of Mn(DS)2 in water. From the quantitative analysis of the data obtained, it was concluded that the Mn(DS)2 molecules in the complex form a nearly micelle-like aggregate, and that most of Mn2+ ions bound onto the micelle-like aggregate or the Mn(DS)2 micelle exist in the Stern layer. In addition, the PVP concentration dependence of the similar quantities in (Mn(DS)2+PVP) solutions with a constant Mn(DS)2 concentration suggested that the polymer-surfactant complex changes its structure at higher PVP concentrations.
  • Yasuyuki Takeda, Masashi Nemoto, Shizuo Fujiwara
    1982 Volume 55 Issue 11 Pages 3438-3440
    Published: 1982
    Released: June 27, 2006
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    Extraction constants of silver and thallium(I) picrates and those of 12-crown-4 (12C4) and benzo-15-crown-5(B15C5) with silver and thallium(I) picrates have been determined between benzene and water at 25 °C. Ionpair complex-formation constants (KMLA,o) of 12C4 and B15C5 with silver and thallium picrates in the benzene solution have been calculated and compared with those of 15-crown-5 (15C5), 18-crown-6 (18C6), dibenzo-18-crown-6 (DB18C6), and dibenzo-24-crown-8 (DB24C8). The KMLA,o sequences of the crown ethers with Ag+ and Tl+ are 15C5, 18C6>DB18C6>B15C5>DB24C8>>12C4 and 18C6>>DB18C6>DB24C8>15C5>B15C5>>12C4, respectively. For both Ag+ and Tl+ systems, the relative sizes of the cation and the crown ether cavity, the number of donor oxygen atoms in the crown ether ring, the basicity of donor oxygen atom, and the flexibility of the crown ether are important factors in determining stabilities of the complexes with these crown ethers in the benzene solution.
  • Goro Wada, Tomiko Inatani, Sachiko Ichimura
    1982 Volume 55 Issue 11 Pages 3441-3445
    Published: 1982
    Released: June 27, 2006
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    The electron transfer reactions between Fe2+ and FeX2+ (X=Cl, SCN, or N3) may take place through the inner- or outer-sphere mechanism or through both in parallel. The process of the outer-sphere mechanism is just equivalent to the process of dissociation of FeX2+ catalyzed by Fe2+ in appearance. When the overall rate constant of the electron transfer reaction and the rate constant of Fe2+-assisted dissociation reaction of FeX2+ are denoted by kE and ko respectively, the fraction r of the outer-sphere mechanism to the total is given in terms of r=2kokE. Thus, the r values were determined with the results that r(Cl)=44% at I=1.5 M (1 M=1 mol dm−3) and 25 °C, r(SCN)=100% at I=0.5 M and 25 °C, and r(N3)=0% at I=0.55 M and 10 °C. These facts suggest that r depends considerably upon the bridging ability of X; formation of binuclear intermediate may be favored by the symmetrical structure and the size of X, which make the inner-sphere mechanism easier with the stronger coordinate bond and the weaker electric repulsion between the two reactants beyond the bridging ligand.
  • Yuzo Saeki, Takashi Shimizu, Akimasa Yajima, Ryoko Matsuzaki
    1982 Volume 55 Issue 11 Pages 3446-3449
    Published: 1982
    Released: June 27, 2006
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    The reaction products of gaseous VCl4 with ammonia were VCl4·4NH3 at 200 °C, VCl4·4NH3, VNx, and NH4Cl at 250–550 °C, and VNx and NH4Cl at 600–1000 °C. At 1100 °C, small amounts of VCl2 and HCl were formed in addition to VNx and NH4Cl. The N/V atomic ratio, x, of the VNx formed was 1.20 at 600 °C, 1.15 at 700 °C, 1.14 at 800 °C, and 1.13 at 900 and 1000 °C. The lattice constants of the VNx formed were shown. The reaction process of gaseous VCl4 with ammonia can be represented as follows: The reaction of gaseous VCl4 with ammonia first occurs to form VCl4·4NH3. Above about 215 °C, the reaction of VCl4·4NH3 with ammonia also occurs to form VNx. At 1100 °C, in addition to these reactions, the reaction of gaseous VCl4 with hydrogen formed by the thermal dissociation of ammonia occurs to form VCl2. On heating the VNx, formed by the vapor-phase reaction, at temperatures higher than 500 °C in an argon atmosphere, the value of x decreased with the increase in the heating temperature to 1.03 at 900–1000 °C.
  • Tadashi Hara, Fujio Okui
    1982 Volume 55 Issue 11 Pages 3450-3454
    Published: 1982
    Released: June 27, 2006
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    The atomic ratio between C, H, O, and N in an ordinary organic compound and a metal organic chelate compound could be simultaneously and satisfactorily determined by the use of 30–130 μg of a sample which cannot be accurately weighed by a microbalance or an ultramicrobalance. This was done by adopting the following modifications: 1) The amount of S was reduced to 0.5 mg from the 5 mg used in the previous studies; 2) the stainless steel column in the gas chromatograph was replaced by a Teflon column; 3) the poly(vinyl chloride) and silicone rubber tubes were replaced by stainless steel and copper tubes; and 4) a correction procedure was established for the analysis of a small amount of a sample.
  • Avadesh Kumar, M. F. Hussain, Masatada Satake, B. K. Puri
    1982 Volume 55 Issue 11 Pages 3455-3458
    Published: 1982
    Released: June 27, 2006
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    A new spectrophotometric method for the determination of palladium after extraction of its 1-pyrrolidinecarbodithioate into molten naphthalene has been developed. Palladium forms a water-insoluble, thermally stable 1:2 complex with 1-pyrrolidinecarbodithioate which is easily extracted into molten naphthalene in the pH range of 3.0–6.0. At room temperature, solid naphthalene containing the metal-complex is dissolved in chloroform (10 ml). It has an absorption maximum in the range of 336–342 nm. Beer’s law holds in the concentration range of 2.5–90.0 μg of palladium in 10 ml of chloroform solution. The molar absorptivity(1 mol−1 cm−1) and sensitivity (μg/cm2) are found to be 6.4×103 and 0.0166, respectively. Samples containing 30 μg of palladium gives a mean absorbance of 0.18 with a standard deviation of 0.0025. Other factors such as amount of reagent and naphthalene, pH, aqueous phase volume and diverse ions have been examined. The method has been applied to the analysis of some alloys.
  • Kensei Kobayashi, Kimikazu Iwase, Masahiro Matsui, Masami Watanabe, Hi ...
    1982 Volume 55 Issue 11 Pages 3459-3463
    Published: 1982
    Released: June 27, 2006
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    Metalloenzyme (alkaline phosphatase) dissolved in lake water has been identified by means of high performance liquid chromatography (HPLC). Water samples were collected from Lake Kasumigaura in Ibaraki, and filtered with a 0.2–0.45 μm membrane filter immediately after sampling. Filtered water was concentrated to 100–2000 fold by ultrafiltration membrane which could concentrate the components of molecular weight larger than 10000. The enzymatic activity of alkaline phosphatase was measured using p-nitrophenyl dihydrogen-phosphate as a substrate. Chelating agents added to the concentrated lake water inhibited the appearance of enzymatic activity, while the enzymatic activity was recovered with addition of zinc ion. The HPLC chromatograms of the concentrated lake water were examined, where an aqueous porous gel column was used for separation. The effluent at molecular weight of ca. 90000 showed specific activity of alkaline phosphatase. Zinc was also found in the same fraction. These facts suggest that alkaline phosphatase with the nature similar to procaryotes was present in the lake water.
  • Tadao Sakai, Noriko Ohno, Takashi Wakisaka, Yoshinori Kidani
    1982 Volume 55 Issue 11 Pages 3464-3467
    Published: 1982
    Released: June 27, 2006
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    A simple determination method of histamine in urine by solvent extraction and atomic absorption spectrophotometry has been established. The method is based on the formation of histamine–Cu(II) chelate cation, followed by the extraction of ion-associates with tetrabromophenolphthalein ethyl ester into 1,2-dichloroethane. Histamine in urine can be successfully determined without separation and purification from other histamine derivatives and amines. A linearity is obtained in the concentration range (0.4–4)×10−5 M (1 M=1 mol dm−3) histamine in aqueous solutions. The relative deviation is ca. 1.8%.
  • Hiroshi Sugimoto, Nobuhiro Ueda, Masayasu Mori
    1982 Volume 55 Issue 11 Pages 3468-3472
    Published: 1982
    Released: June 27, 2006
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    A new series of iron(III) porphyrins having various phenoxide anions as the axial ligand, [FeIII(porphyrin)(4-X–C6H4O)] (porphyrin=octaethylporphyrin and tetraphenylporphyrin; X=OCH3, CH3, H, C6H5, Cl, Br, COCH3, CN, CHO, and NO2) were synthesized. All these complexes are five-coordinated high-spin complexes (S=5⁄2). Their electrochemical behaviors were investigated by the cyclic voltammetry and the controlled potential coulometry. The complexes showed significantly negative potentials for the FeII/FeIII redox couple (−0.4–−0.8 V). A good linear relationship was found between the half-wave potentials of the FeII/FeIII redox couple and the Hammett σ-values of the substituent X. A new characteristic feature is the appearance of the redox peaks of the coordinated phenoxide anions near the redox couple of the porphyrin ring oxidoreduction. The role of the tyrosine-67 in the enzymatic mechanism for cytochrome c is discussed.
  • Ken-ichi Okamoto, Katsuhiko Wakayama, Hisahiko Einaga, Masaaki Ohmasa, ...
    1982 Volume 55 Issue 11 Pages 3473-3476
    Published: 1982
    Released: June 27, 2006
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    The crystal structure of the title complex, which was chromatographically obtained as the first eluted isomer, has been determined by the X-ray diffraction method. The dark-brown needle crystal was hexagonal, space group P61, a=21.035(5), c=6.459(3) Å, Z=6, and the final R value was 0.076 for 1504 non-zero reflections. Of three possible isomers for the (diethylenetriamine)(L-penicillaminato)cobalt(III) complex, the complex isolated has trans(N1N) configuration. The average Co–N distance for the nitrogen atoms bonded cis to the sulfur atom is 1.961 Å, whereas the trans Co–N length is 2.007 Å.
  • Takushi Yokoyama, Yukio Hirai, Norimasa Yoza, Toshikazu Tarutani, Shig ...
    1982 Volume 55 Issue 11 Pages 3477-3481
    Published: 1982
    Released: June 27, 2006
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    Flow injection analysis (FIA) was developed for the spectrophotometric determination of silicic acid based on the formation of a yellow molybdosilicic acid (yellow method) and a heteropoly blue complex (blue method). In the yellow method, silicic acid in the concentration range of 2 to 100 ppm (SiO2) could be determined at a sampling rate of 60 samples/h. The FIA system was modified to determine silicic acid in the presence of orthophosphate. Oxalic acid was used for the decomposition of molybdophosphoric acid. The modified system was employed for the rapid and selective determination of silicic acid in well and river waters. In the blue method, ascorbic acid was used to reduce the yellow molybdosilicic acid to a heteropoly blue complex. Silicic acid in the concentration range of 0.02 to 1.0 ppm (SiO2) could be determined at a sampling rate of 40 samples/h. The FIA system was also modified to determine silicic acid in the presence of orthophosphate. The reducing agent was introduced after molybdophosphoric acid had been completely decomposed by adding oxalic acid. The modified system was employed for the determination of silicic acid in sea water.
  • Shunichi Fukuzumi, Nobuaki Nishizawa, Toshio Tanaka
    1982 Volume 55 Issue 11 Pages 3482-3490
    Published: 1982
    Released: June 27, 2006
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    Electron transfer reactions from tetrakis(isocyanide)rhodium(I) ([RhL4]+ to iron(III) complexes of the [Fe(N–N)3]3+ type (N–N=1,10-phenanthroline, 2,2′-bipyridine) proceed through precursor complexes formed between [RhL4]+ and [Fe(N–N)3]3+ with 1:1, 1:2, and 2:1 stoichiometry. A similar scheme is suggested for the reaction of bis(isocyanide)bis(triphenylphosphine)rhodium(I) with the same oxidants. The intramolecular electron transfer rate constants k1 in the 1:1 precursor complexes have been determined in MeCN at 298 K. In accordance with Marcus theory, the logk1 values are linearly related with the reduction potentials of oxidants with the theoretical slope of 8.5. The [RhL4]+ cations form oligomers in MeCN; [RhL4+]n (n=2,3), and the equilibrium constants for oligomerization have been determined. For a given oxidant [Co(bpy)3]3+ (bpy=2,2′-bipyridine), the logk1 value of [RhL4+]n increases in parallel with the HOMO energy of [RhL4+]n; monomer<dimer<trimer.
  • Susumu Kitagawa, Megumu Munakata, Shoji Okada
    1982 Volume 55 Issue 11 Pages 3491-3495
    Published: 1982
    Released: June 27, 2006
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    The complexes of 1,8-di(2-pyridyl)-3,6-dithiaoctane(pdto) with CuX(X=Cl and Br) and [Cu(CH3CN)4]ClO4 have been synthesized in chloroform, methanol, ethanol, and acetone. Their absorption spectra show an intense metal-to-ligand charge-transfer band at 307 nm: This band is assigned to pyridyl nitrogen←Cu. [Cu(pdto)]+ (1) has been prepared from [Cu(CH3CN)4]ClO4, its pdto acting as a four-coordinate ligand. CuX reacts with pdto to yield two complexes: One is 1, and the other is [CuX(pdto)] (2). Both complexes are four-coordinate, but in the 2 one of the two pyridyl groups is dissociated. The complex 2 is unstable and is oxidized by oxygen. Neither complex reacts with CO, indicating the tight binding of pdto with Cu(I). The 1 and 2 are equilibrated in solution. The 1H NMR spectra well demonstrate that 2 is dominant in chloroform and that 1 is the principal form in alcohol, while the 1/2 ratio is 3/7. This solvent-dependence is ascribed to the coordination ability and/or polarity of the solvent.
  • Seiji Oka, Yukio Yamamoto, Koichiro Hayashi
    1982 Volume 55 Issue 11 Pages 3496-3499
    Published: 1982
    Released: June 27, 2006
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    Argon plasma treatment of column packings for gas chromatography was examined with commercially obtained diatomaceous earth coated with several kinds of stationary liquid phases, such as squalane, Apiezon L, dioctyl phthalate, Silicone DC, and polyethylene glycol. It was found that the plasma treatment improves chromatographic properties of all the packings examined except those with polyethylene glycol. The effect of the plasma treatment is attributable to the reduction of support adsorptivity by the formation of an inert coating on the support surface. The plasma treatment of Chromosorb W coated with 5% squalane was compared with dimethyldichlorosilane (DMCS) treatment of the acid-washed (AW) support, the so-called AW-DMCS-treatment of support. Although the AW-DMCS-treatment is superior to the plasma treatment for the reduction of support adsorptivity, a complete elimination of the adsorptivity was attained by the plasma treatment of the packing having the AW-DMCS-treated support.
  • Yonezo Maeda, Hiroki Ohshio, Yoshimasa Takashima
    1982 Volume 55 Issue 11 Pages 3500-3505
    Published: 1982
    Released: June 27, 2006
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    The Mössbauer emission spectra of [57Co(terpy)2]X2 (X=Cl and ClO4), [57Co(snn)2](ClO4)2, and [57Co(snnme)2](ClO4)2 (terpy=2,2′ : 6′2″-terpyridine, snn=N-(2-pyridylmethylene)-2-(methylthio)aniline, and snnme=N-(6-methyl-2-pyridylmethylene)-2-(methylthio)aniline) were examined. These cobalt complexes show thermally induced spin crossover behavior and the temperature dependence of their magnetic moment varies with the counter anion, although the corresponding iron complexes are in a low-spin state. The high-spin iron(II) species ascribed to a metastable form are observed in the emission spectra of [57Co(terpy)2](ClO4)2·2H2O and [57Co(snnme)2](ClO4)2, and their spectral areas increase with decreasing source temperature. The effective vibrating mass for the iron complex observed in the emission spectra of [57Co(snnme)2](ClO4)2 was calculated from the temperature dependence of the isomer shift value, and was used to distinguish whether the iron complex formed by EC-decay of a cobalt-57 atom is stable or metastable.
  • Takumi Maeda, Keiichi Kimura, Toshiyuki Shono
    1982 Volume 55 Issue 11 Pages 3506-3509
    Published: 1982
    Released: June 27, 2006
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    Solvent extractions of alkali metal picrates were carried out using newly synthesized poly- and bis(crown ether)s containing benzo-12-crown-4 moieties in a water-chloroform system. The extraction equilibrium constants(Ke) and the complexation constants (Kc) in the chloroform phase were determined at 25 °C. The Ke values for the alkali metal cations decreases as follows: Na+>K+>Rb+≥Cs+ with the poly(benzo-12-crown-4) and K+, Rb+, Cs+>Na+ with the bis(benzo-12-crown-4). The poly(benzo-12-crown-4) improved the sodium-ion selectivity of the corresponding monocyclic analog because of the easy formation of 2:1 crown ether unit-cation complexes assisted by the cooperative action of two adjacent crown ether units, while the bis(benzo-12-crown-4) did not. A separate extraction experiment was also undertaken in a water-dichloromethane system in order to compare the extractability of these benzo-12-crown-4 derivatives with that of 12-crown-4.
  • Hidehiro Daidoji, Shohei Tamura
    1982 Volume 55 Issue 11 Pages 3510-3514
    Published: 1982
    Released: June 27, 2006
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    The determination of yttrium, samarium, and dysprodium by means of graphite-furnace atomic absorption spectrometry (AAS) was studied by a tantalum boat inserted into a graphite tube atomizer. These elements could not be determined by the use of a commercial graphite tube. In the atomization from a tantalum boat, better analytical sensitivities and negligible memory effects for these rare earths are obtained. The analytical sensitivities of yttrium, samarium, and dysprodium with the tantalum boat were 0.60 ng, 0.86 ng, and 0.17 ng respectively. This method was applied for the determination of yttrium, samarium, and dysprodium in a mish metal. The measurements were performed with slightly acidified solutions (0.01 mol dm−3 HCl or HNO3). The sensitivities and the precisions for these elements decreased with increasing acid concentration. An enhancement in the sensitivities of yttrium and dysprodium upon the addition of a large excess of lanthanum, neodymium, and praseodymium salts were observed. The yttrium, samarium, and dysprodium in a mish metal were determined with both analytical curves of standard solutions containing an excess of lanthanum, cerium, and neodymium ions and of the standard addition. The precisions for this work were in the 3–9.3% range.
  • Hirondo Kurihara, Fumihiro Arifuku, Isao Ando, Minoru Saita, Rika Nish ...
    1982 Volume 55 Issue 11 Pages 3515-3519
    Published: 1982
    Released: June 27, 2006
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    The equilibria among the species of [tetrakis(1-methylpyridinium-4-yl)porphine]iron(III) ion (Fe(III)–TMPyP) in aqueous solution and the redox reactions of their central metals were investigated by means of spectrophotometric, electrochemical and spectroelectrochemical methods. Two acid-dissociation equilibria involving three monomeric species of Fe(III)–TMPyP were found: one with a pKa of 5.5 and the other with a pKa of ca. 12. After electrochemical reduction, an equilibrium between two monomeric species of Fe(II)–TMPyP with a pKa of 11 was observed. In the Fe(III)–TMPyP solution at relatively high concentration, two additional different species, probably dimeric, were found in the pH regions of 5–8 and 9–13, respectively. The consistency of specification of the species with the scheme of redox reactions is discussed.
  • Masaki Tachibana, Makoto Hayakawa, Motohisa Furusawa
    1982 Volume 55 Issue 11 Pages 3520-3522
    Published: 1982
    Released: June 27, 2006
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    9,10-Phenanthrenequinone (9,10-PQ) reacts with guanidine in an alkaline medium to form 2-amino-1H-phenanthro[9,10-d]imidazole. The reaction can be used for the fluorometric determination of 9,10-PQ, since the reaction product is fluorescent in an acidic solution. A dimethyl sulfoxide-methanol mixture is suitable as the solvent. A sample solution was allowed to stand for 15 min at room temperature after the additions of guanidine hydrochloride and sodium methoxide solutions, followed by the addition of hydrochloric acid. After the solution had been allowed to stand for 20 min, the fluorescence intensity of the solution was measured at 403 nm with excitation at 363 nm. The fluorescence intensity was stable for at least 8 h. The determination limit of 9,10-PQ was 50 ng.
  • Masahiko Kato, Hisako Kobayashi, Hiroyuki Yamamoto, Koji Seto, Satoru ...
    1982 Volume 55 Issue 11 Pages 3523-3532
    Published: 1982
    Released: June 27, 2006
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    The photolysis of 1-substituted 1a,7b-dihydro-1H-cyclopropa[a] naphthalenes in the presence of Michler’s ketone leads principally to 5-substituted 5H-benzocycloheptenes as primary products via a stepwise mechanism. The reaction proceeds smoothly with inversion of the migrating carbon if there is no steric hindrance, but it proceeds predominantly with retention if the inversion course is severely suppressed by steric hindrance. The marked difference in the exo-endo ratio of the secondary photocyclization products depending on the irradiation conditions was also recognized for 1-methoxycarbonylmethyl derivative.
  • Tadao Hinohara, Kazuo Amano
    1982 Volume 55 Issue 11 Pages 3533-3535
    Published: 1982
    Released: June 27, 2006
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    The main photochemical reaction of 4-hydroxy-diphenylamine (R) in the aerated cyclohexane wa photocyclization. In the presence of polychloromethane (Q), however, photooxidation to N-phenyl-p-benzoquinone monoimine (PBQI) took place instead of the photocyclization. The formation of PBQI was in parallel with the quenching of fluofescehce by Q, and it was proposed that both PBQI formation and fluorescence quenching by Q proceed via exciplex, (R+Q)*, which is nonfluorescent. The kinetic analysis based on this reaction mechanism gives the fluorescence quenching constant, which is in good agreement with the value obtained directly from the fluorescence quenching study. This agreement strongly supports the validity of the proposed reaction mechanism.
  • Hiroaki Egawa, Takamasa Nonaka, Noboru Kozakura
    1982 Volume 55 Issue 11 Pages 3536-3540
    Published: 1982
    Released: June 27, 2006
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    Some crosslinked chelating resins were prepared and the catalytic activity of the resin-rnetal chelates for the oxidation; of 2,6-dihydroxyphenylacetic acid(homogentisic acid) and hydroquinone was investigated. The resin–Cu(II), resin–Au(III), and resin–Ag(I) chelates had a high catalytic activity. Especially resin–Cu(II) chelate had the highest catalytic activity for these oxidation reactions, and its activity did not decrease even after repeated use. The chelating resins having hydrazide or polyethylenepolyamine side chains had a high catalytic activity. In order to have a high catalytic activity, the resin–metal chelates must leave coordination places open for the substrate to coordinate to metal in the chelates. In the oxidation of homogentisic acid, the catalytic activity of gel type resin increased with the increase of crosslinking degree in the range from 0.5% to 7.5%. However, the catalytic activity of the macroreticular chelating reins was scarcely affected by the degree of crosslinking. The oxidation reaction of homogentisic acid showed a kinetic behavior of a typical Michaelis-Menten type.
  • Norio Tsubokawa, Naoki Tareda, Yasuo Sone
    1982 Volume 55 Issue 11 Pages 3541-3545
    Published: 1982
    Released: June 27, 2006
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    The two-phase(aqueous and organic phase) dehydrogenation of hydrazo nitriles by an aqueous solution of potassium hexacyanoferrate(III), using carbon black as the catalyst, was carried out at 40 °C with shaking. In the presence of carbon black, the two-phase dehydrogenation of hydrazo nitriles was accelerated, and the corresponding azo nitriles were obtained in good yields. The catalytic activity of channel blacks was larger than that of furnace blacks. Moreover, the increasing content of phenolic hydroxyl groups tended to increase the catalytic activity of carbon blacks. It became apparent that phenolic hydroxyl groups on the surface of carbon black act as an electron-transfer catalyst in the two-phase dehydrogenation. The reaction scheme was considered to be as follows. In the aqueous phase, phenolic hydroxyl groups on the surface are oxidized by an aqueous solution of K3[Fe(CN)6] to give phenoxyl radicals, and then the carbon black with phenoxyl radicals is transferred into the organic phase, which contains hydrazo nitriles. Subsequently, in the organic phase, the phenoxyl radicals oxidize the hydrazo nitriles to give the corresponding azo nitriles, by which phenolic hydroxyl groups are regenerated. Thus, it was concluded that phenolic hydroxyl groups on the surface are recycled and that carbon black mediates the redox reaction occurring between aqueous and organic phases.
  • Saizo Shibata, Hajime Matsushita, Hajime Kaneko, Masao Noguchi, Masahi ...
    1982 Volume 55 Issue 11 Pages 3546-3551
    Published: 1982
    Released: June 27, 2006
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    Asymmetric transformation of racemic 2-phenyl- and 2-chloroalkanoic acids via oxazolines into the corresponding optically active acids was investigated using (S)-phenylalaninol as a chiral auxiliary. The asymmetric transformation was performed by metalation of the oxazolines with butyllithium followed by protonation of the resulting lithiooxazolines. 2-Phenyl- and 2-chloroalkanoic acids were obtained in the optical yields of 29–53% and 45–73%, respectively, by the acidic hydrolysis of the chiral oxazolines thus formed. The mechanism of the asymmetric transformation was discussed.
  • Toshisada Shimadate, Sachiyo Chiba, Kazuko Inouye, Teruhiko Iino, Yosh ...
    1982 Volume 55 Issue 11 Pages 3552-3554
    Published: 1982
    Released: June 27, 2006
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    A simple method for the preparation of aryl 1-thioglycosides is described. The reaction of D-glucose pentaacetate or 2-acetamido-2-deoxy-D-glucose tetraacetate with arenethiols in the presence of zinc chloride under fusion conditions formed their 1-thioglycosides in good yields. Some Lewis acids in addition to zinc chloride were studied as catalysts in the reaction.
  • Tamotsu Fujisawa, Toshio Sato, Yoshihiko Gotoh, Masatoshi Kawashima, T ...
    1982 Volume 55 Issue 11 Pages 3555-3559
    Published: 1982
    Released: June 27, 2006
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    Primary alkyl Grignard reagents react regioselectively with diketene in the presence of cobalt(II) iodide to afford 3-methylenealkanoic acids in good yields. The synthetic utility of this reaction is demonstrated in the syntheses of terpenoids by two methods. Utilizing the isomerization of double bond of 3-methylenealkanoic acids, geranic acid and farnesic acid were obtained in two steps. Another method, the tandem [3,3] sigmatropic rearrangement of the corresponding allylic esters was used for the synthesis of C18-Cecropia juvenile hormone.
  • Keiji Kobayasm, Yoshio Kodama, Motohiro Nishio, Tadashi Sugawara, Hiiz ...
    1982 Volume 55 Issue 11 Pages 3560-3564
    Published: 1982
    Released: June 27, 2006
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    The conformations of the diastereoisomers of 1-phenylethyl phenyl (1), 1-phenylethyl p-tolyl (2), 1-phenylpropyl phenyl sulfoxides (3) were studied by NMR spectroscopy, largely by means of the computer simulation of the lanthanoid-induced shifts. It has been suggested that the rotamer in which the aromatic group (Ar) is
    4C_6H_5CH(R)–SO–Ar& 1:R=& &CH_3,& Ar=&C_6H_5
    & 2:& &CH_3,& &C_6H_4CH_3(p)
    & 3:& &C_2H_5,& &C_6H_5
    gauche to the phenyl (Ph) and anti to the alkyl (R) group is most populated in the conformational equilibria of (RS/SR)-1, 2, 3, and (RR/SS)-3. For (RR/SS)-1 and 2, on the other hand, the most important contributor has been suggested to be the rotamer in which Ar is flanked by Ph and R. The results have been discussed in the light of the presence of attractive interactions between relevant groups.
  • Tohru Nishiwaki, Tsutomu Shinoda, Kinji Anda, Mitsuhiko Hida
    1982 Volume 55 Issue 11 Pages 3565-3568
    Published: 1982
    Released: June 27, 2006
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    The photodechlorinations of 2,3-dichlorobiphenyl (2,3-DCB) and 3,4-dichlorobiphenyl (3,4-DCB) in 2-propanol gave 3-chlorobiphenyl and 4-chlorobiphenyl respectively. The quantum yields of monochlorobiphenyl formation were 0.2 for 2,3-DCB and 0.06 for 3,4-DCB, independent of the substrate concentration and the wavelength of the exciting light. On the basis of the results obtained in quenching experiments using cis-1,3-pentadiene, it was concluded that 2,3-DCB was photodechlorinated exclusively in the excited singlet state, while 3,4-DCB was photodechlorinated in both excited singlet and triplet states. In the case of 3,4-DCB, the relative contributions of excited singlet and triplet states to the total dechlorination were evaluated as 0.8 and 0.2 respectively. The participation of the excited triplet state in the photodechlorination of 3,4-DCB was ascertained both by quenching reactions with biacetyl as a quencher and by photosensitized dechlorinations with acetone and acetophenone as sensitizers.
  • Tohru Nishiwaki, Tsutomu Shinoda, Kinji Anda, Mitsuhiko Hida
    1982 Volume 55 Issue 11 Pages 3569-3572
    Published: 1982
    Released: June 27, 2006
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    The multiplicity of the photo-excited state responsible for the dechlorination reaction of monochlorobiphenyls was determined in 2-propanol. Linear Stern-Volmer plots were obtained by the use of 1,3-cyclohexadiene for the dechlorination reactions of 2- and 3-chlorobiphenyl; the slopes were 35.7 and 11.0 dm3 mol−1 respectively. Fluorescence emissions were also quenched, and the quenching constants for 2- and 3-chlorobiphenyls were in accord with the respective values of the slope obtained from the Stern-Volmer plot for the reaction. The reaction of 4-chlorobiphenyl was quenched by cis-1,3-pentadiene, but was accelerated by 1,3-cyclohexadiene. Photosensitized dechlorinations of monochlorobiphenyls took place with several ketones, such as acetone and acetophenonc. These sensitized reactions were, however, very inefficient compared with the reactions in the direct excitations, except in the case of 4-chlorobiphenyl. It was, then, concluded that the dechlorinations of 2- and 3-chlorobiphenyl occurred only from the excited singlet state, while that of 4-chlorobiphenyl took place predominantly from the excited triplet state.
  • Shosuke Yamamura, Masatake Niwa, Yukimasa Terada, Mikie Nonoyama
    1982 Volume 55 Issue 11 Pages 3573-3579
    Published: 1982
    Released: June 27, 2006
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    Several novel neolignans and neosesquilignans represented by heterotropanone and heterotropatrione, respectively, have been isolated from the plant Heterotropa takaoi M. and their structures also been elucidated on the basis of their spectral data closely related to that of asatone. From a biogenetic point of view, furthermore, these neolignans and neosesquilignans were chemically correlated to one another.
  • Norimasa Nogami, Michinori Oki, Shoichi Sato, Yoshihiko Saito
    1982 Volume 55 Issue 11 Pages 3580-3585
    Published: 1982
    Released: June 27, 2006
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    Crystals of 1,2,3,4-tetrachloro-9-(2-oxopropyl)triptycene grown from tetrahydrofuran-hexane were found to contain 1:1 ap and ±sc rotational isomers about the C9–CPr bond by the X-ray diffraction method. The molecular structures had the following features. The acetyl group in the 9-substituent takes an O-inside, relative to the triptycene skeleton, conformation in both forms. The benzene rings are deformed by the steric effect to form boats. The 2-oxopropyl groups in both forms were planar within the experimental error but the C2–C1 bond in the 2-oxopropyl group was appreciably shorter in the ±sc conformation than that in the ap. The results are discussed on the ground of steric repulsion and the existence of the interaction between the C=O and the Cl groups which are located only 3.035 Å apart in the ±sc form.
  • Keiryo Mitsuhashi, Kazuyuki Takahashi, Takeo Kawahara, Yoshimitsu Iker ...
    1982 Volume 55 Issue 11 Pages 3586-3589
    Published: 1982
    Released: June 27, 2006
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    The reactions of 4,5-dicyanoimidazoles with methyl isocyanate gave 7-cyano-1-imino-2-methyl-2,3-dihydro-1H-imidazo[3,4-c]imidazol-3-ones (2), while the similar reactions with phenyl isocyanate resulted in the formation of the tricyclic imidazoles, 1 1-imino-6,10-diphenyl-2,4,6,8,10-pentaazatricyclo[5.4.1.04,12]dodeca-1(12),2,7-triene-5,9-diones (3) and the same type of the tricyclic imidazoles 4 were obtained by carbamoylation of 2 with phenyl isocyanate. The reactions of 2, 3, and 4 with amines were further investigated.
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