Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
Volume 65 , Issue 3
Showing 1-50 articles out of 56 articles from the selected issue
  • Takashi Sakai, Kou Wada, Takahiko Murakami, Kiichiro Kohra, Norihisa I ...
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 3 Pages 631-638
    Published: 1992
    Released: July 14, 2006
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    The bakers’ yeast reduction of a series of 2-oxoalkyl arenecarboxylates [R(C=O)CH2O(C=O)C6H4-p-X] (1af) (R = CH3 to n-C6H13; X = H) and the phenyl-modified derivatives (1gl) (R = n-C5H11, X = OH, CH3, F, Cl, Br, or I) as well as 1-chloro-2-alkanones R(C=O)CH2Cl (6af) (R = CH3 to n-C6H13) were systematically investigated. The substrate specificities, configuration and %ee of the reduction products were found to be highly dependent on the length of the alkyl group (R) and the α substituent. Thus, the benzoates 1af gave optically active 2-hydroxyalkyl benzoates (2af) (R, configuration, %ee) (a: CH3, S, 99; b: C2H5, S, 98; c: C3H7, S, 26; d: n-C4H9, R, 55; e: n-C5H11, S, 15; f: n-C6H13, S, 63) in 11–91% yields. Among the modification experiments of the phenyl group, 1gl, the p-iodo substituent markedly increased the ee from 15 to 71%, although the yield was rather lowered (22% yield). The reduction of α-chloro ketones 6af also gave optically active 1-chloro-2-alkanols (7af) [(R, configuration, %ee) (a: CH3, S, 83; b: C2H5, S, 54; c: C3H7, R, 49; d: n-C4H9, R, 80; e, n-C5H11, R, 65; f, n-C6H13, R, 41)] in 16–69% yields.
  • Jun-ichiro Setsune, Yasushi Saito, Yoshihiro Ishimaru, Mitsuhiro Ikeda ...
    1992 Volume 65 Issue 3 Pages 639-648
    Published: 1992
    Released: July 14, 2006
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    Chlorocobalt(III) porphyrins showed novel UV-vis and 1H NMR spectra in a non-coordinating solvent to suggest displacement of the cobalt out of the porphyrin plane toward the axial ligand in solution. They underwent insertion of alkynes into the Co–Cl bond to generate σ-(trans-2-chlorovinyl)cobalt(III) complexes. In a special case, novel [4+2]cycloaddition reaction between the Co–N–C(pyrrole-α)-C(meso) moiety of [CoIIICl(oep)] [oep = octaethylporphyrin dianion] and dimethyl acetylenedicarboxylate took place. The reaction behavior of chlorocobalt(III) porphyrins was compared with that of diaquaperchloratocobalt(III) porphyrins which also reacted with alkynes in the presence of 2,6-lutidine to give analogous σ-vinylcobalt(III) porphyrins with a 2,6-dimethyl-1-pyridinio substituent occupying the trans-β-position of the σ-vinyl group. While the methoxycarbonyl group of methyl propiolate was directed to the α side of these σ-vinylcobalt(III) complexes, the phenyl group of phenylacetylene was found to be directed to the α side of σ-(2-chlorovinyl)cobalt(III) porphyrin and to the β side of σ-[2-(2,6-dimethyl-1-pyridinio)vinyl]cobalt(III) porphyrin.
  • Takeo Yamaguchi, Takahiro Seki, Takashi Tamaki, Kunihiro Ichimura
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 3 Pages 649-656
    Published: 1992
    Released: July 14, 2006
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    Thirteen hemithioindigo (HT) derivatives bearing alkyl chains are newly synthesized and their photochromism and emission properties are investigated. The Z/E photoisomerisms of these compounds in organic solvents are essentially in agreement with data reported by Mostoslavskii and Izmail’skii (J. Gen. Chem. USSR, Engl Transl.), 31, 21 (1961), and subsequent papers). At 77 K both the E and Z isomers of HT chromophore emit fluoresscences of comparable intensities, whereas at room temperature very weak fluorescence is observed only from the Z isomer. Examination of repeatable numbers of Z/E photoisomerization reveals that the HT chromophore possesses remarkable inherent photofatigue resistance.
  • Takahiro Seki, Takashi Tamaki, Takeo Yamaguchi, Kunihiro Ichimura
    1992 Volume 65 Issue 3 Pages 657-663
    Published: 1992
    Released: July 14, 2006
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    Photochromic behaviors of hemithioindigo (HT) derivatives in bilayer membrane matrices and related aqueous system are investigated. HT derivatives were incorporated into bilayer membrane matrices at a molar ratio to bilayer amphiphiles of 0.01. Under these conditions, HT amphiphiles having an ammonio group disperse molecularly in the array bilayer membranes, and show the simple photochromism as in the organic solutions. For a HT derivative having no hydrophilic group, on the other hand, irreversible photobleaching proceeds in addition to the photochromic reaction possibly as a result of cluster formation in the bilayer membranes. E-Form conversion at the photostationary state and the E to Z thermal isomerization rate is largely influenced by the crystal to liquid crystal phase transition of the bilayer matrices.
  • Yasushi Sugihara, Yasumasa Watanabe, Hiromi Kumura, Tomoyuki Nakamura, ...
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 3 Pages 664-667
    Published: 1992
    Released: July 14, 2006
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    The thermolysis mechanism of 1,1-bis(t-butyldioxy)cyclohexane (6) has been studied in solutions. The activation parameters obtained in cumene are ΔH = 139.5 kJ mol−1 and ΔS = 44.8 J K−1 mol−1, and the volatile products are t-butyl alcohol, t-butyl peroxyhexanoate, and 2,3-dimethyl-2,3-diphenylbutane along with minor products of acetone, cyclohexanone, and t-butyl 1-methyl-1-phenylethyl peroxide. The thermolysis of 6 in benzene gave acetone and t-butyl alcohol as major volatile products. The polyester of 2-hydroxyhexanoic acid was obtained both in cumene and benzene as a non-volatile product, and the yield was as high as 76% in benzene. These facts indicate that [1-(t-butyldioxy)cyclohexyl]oxyl radical (7) undergoes a facile ring-opening reaction yielding 5-(t-butyldioxycarbonyl)pentyl radical (8). The resulting radicals abstract hydrogen atoms either intra- or intermolecularly. The former reaction is predominant in the absence of good hydrogen donors, affording 2-hexanolide and ultimately the corresponding polyesters.
  • Katsumi Yonemoto, Kazumasa Honda, Isao Shibuya, Yoichi Taguchi, Tohru ...
    1992 Volume 65 Issue 3 Pages 668-673
    Published: 1992
    Released: July 14, 2006
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    The ring expansion reactions of 1,3-oxathiolium salts (1) using NaN3 and an I2–aq NH3 system resulted exclusively in the formation of 1,4,2-oxathiazines (3) by incorporation of a nitrogen atom into the C–O bond in 1. On the other hand, the reaction of 1 with dialkylamino(thioxo)methanesulfenamides, another type of N-expansion reagent, gave di-5-thiazolyl sulfide derivatives (4) in addition to 3. The structure of 4 was confirmed by X-ray crystallographic analysis. It was speculated that the formation of 4 goes via initially-formed 3. Furthermore, 1 reacted with another N-unsubstituted sulfenamides having a heterocyclic substituent such as a 2-pyridyl and 2-benzothiazolyl group to afford 2-pyridyl 5-thiazolyl sulfide and 2-benzothiazolyl 5-thiazolyl sulfide derivatives, respectively, together with 3. The stability and reactivity of oxathiazines 3, which comprise an electron-rich π-system, were also examined.
  • Hidenori Okamoto, Tadashi Kobutani, Shozo Kato
    1992 Volume 65 Issue 3 Pages 674-678
    Published: 1992
    Released: July 14, 2006
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    Various N-(1-aryl-1-alkenyl)-2-chloroacetamides bearing alkoxymethyl or alkylthiomethyl group on amide nitrogen were synthesized by a one-step hydroamidation of 2-aza-1,3-pentadienes. Some N-(1-aryl-1-alkenyl)-2-chloroacetamides were found to have high herbicidal activities against upland farm weeds.
  • Mareyuki Takahashi, Erika Komuro, Etsuo Niki, Kunihiko Tanaka
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 3 Pages 679-684
    Published: 1992
    Released: July 14, 2006
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    The antioxidant activities of saturated fatty acid esters of L-ascorbic acid were studied in the oxidations of soybean phosphatidylcholine liposomes in aqueous dispersions aiming at elucidating their action as antioxidants in the liposomal membranes, especially the effects of number and length of the fatty acid ester side chains at either 6- or both 5- and 6-positions. Ascorbic acid esters were found to act as radical-scavenging antioxidants in the oxidations initiated by either aqueous free radical attacking from outside of the membrane or by lipophilic radical generated within the membranes. They inhibited the oxidation cooperatively with α-tocopherol in the membranes and reduced the rate of α-tocopherol consumption, their sparing effects on α-tocopherol being greatest for the monoesters and for the esters with the shortest fatty acid chains within the diester group. It was concluded that the intramembrane and intermembrane mobilities of ascorbic acid esters decreased with increasing number and length of fatty acid chains.
  • Masayuki Hoshi, Yuzuru Masuda, Akira Arase
    1992 Volume 65 Issue 3 Pages 685-691
    Published: 1992
    Released: July 14, 2006
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    The reaction of 3-chloro-1-trimethylsilyl-1-propyne with a stoichiometric amount of dialkylborane proceeds to the monohydroboration stage, giving a mixture of regioisomers, (Z)-dialkyl(3-chloro-1-trimethylsilyl-1-propenyl)borane and (Z)-dialkyl[1-chloromethyl-2-(trimethylsilyl)vinyl]borane. The hydroboration mixture is protonolyzed with acetic acid to give (Z)-3-chloro-1-trimethylsilyl-1-propene in a quantitative yield. Treatment of the hydroboration mixture with aqueous sodium hydroxide gives a good yield of highly pure (E)-3-trimethylsilyl-2-alkene whose alkyl group migrates from the boron atom. On the other hand, successive treatment of the hydroboration mixture with methyllithium and acetic acid gives a good yield of 3-trimethylsilyl-1-alkene whose alkyl group migrates from the boron atom. The above procedures provide convenient syntheses of (E)-3-trimethylsilyl-2-alkenes and 3-trimethylsilyl-1-alkenes. It is proposed that both products are afforded through the corresponding allylboranes derived from (Z)-dialkyl(3-chloro-1-trimethylsilyl-1-propenyl)borane, respectively. Thus, the former is formed by hydrolysis of alkyl[1-alkyl-1-(trimethylsilyl)allyl]hydroxyborane, while the latter is formed by protonolysis of alkylmethyl[3-alkyl-3-(trimethylsilyl)allyl]borane.
  • Toshihiko Hoshi, Jun Okubo, Fumitoshi Imaizumi, Isao Ono, Michio Kobay ...
    1992 Volume 65 Issue 3 Pages 692-697
    Published: 1992
    Released: July 14, 2006
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    The polarized electronic absorption spectrum of 9-cyanoanthracene has been measured in a stretched poly(vinyl alcohol) (PVA) film at 101 K, and the polarizations of the electronic transitions determined. It was found that the longer-molecular-axis polarized bands are at 364.4, 262. 1, and 229 nm, and that the shorter-molecular-axis polarized ones are at 411.2 and 223 nm. The absorption spectra of 9-cyanoanthracene were measured in MP (a 1:1 mixed solvent of methylcyclohexane and isopentane) at room and lower temperatures. It was found that additional bands appear at the lower energy sides of the corresponding monomer bands at lower temperatures. These spectral changes may be interpreted as being due to dimer formation. The dimer may be stabilized mainly through dipole-dipole interactions between the two cyano groups taking on a C2h symmetry. The 412.5, 363.5 and 281.5 nm bands of the dimer are assigned to the calculated S1←S0 (Bu←Ag), S4←S0 (Au←Ag) and S8←S0 (Au←Ag) transitions, respectively; these transitions correspond to the S1←S0 (A1←A1), S2←S0 (B2←A1) and S3←S0 (B2←A1) transitions of the monomer.
  • Hiroshi Yoshida, Fumitaka Utsumi, Hideki Suzuki, Satoru Ito, Shin-ichi ...
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 3 Pages 698-702
    Published: 1992
    Released: July 14, 2006
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    The reactions of monoalkylthio- or monoarylthio-substituted cyclopropenium salt (1) with a number of secondary amines were studied. The amines, such as N-methylaniline, yielded indenes, whereas N-alkyl- or N-arylbenzylamines gave 1-alkyl- or 1-aryl-2-phenylpyrroles in low-to-moderate yields, depending on the kinds of substituents of the amines and 1. The reaction with N-isopropylbenzylamine-α,α-d2 (i-PrNHCD2Ph) resulted in the formation of the 1-isopropyl-2,3,5-triphenylpyrrole-4-d, clearly indicating the intramolecular H-abstraction mechanism via vinylcarbene intermediates for the formation of pyrroles. The reaction of 1 with tosylhydrazones afforded the ring opend hydrazide, while with phenyl-, methyl-, and t-butylhydrazines gave 1,4,5-trisubstituted pyrazoles in small yields.
  • Takashi Morimoto, Masao Hirano, Takayoshi Hamaguchi, Masahide Shimoyam ...
    1992 Volume 65 Issue 3 Pages 703-706
    Published: 1992
    Released: July 14, 2006
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    Aliphatic primary alcohols and 1,ω-diols were oxidized to the dimeric esters and lactones, respectively, by peracetic acid in ethyl acetate in the presence of sodium bromide under mild conditions. Aliphatic secondary and benzylic alcohols were converted smoothly to the corresponding carbonyl compounds by the same system.
  • Masayasu Iida, Yukari Hata
    1992 Volume 65 Issue 3 Pages 707-714
    Published: 1992
    Released: July 14, 2006
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    The hydration and alkali-ion binding of an aggregate of the dibutyl phosphate (DBP) ion in its isotropic aqueous solution were investigated by measuring the nuclear magnetic relaxation times for 17O of H2O, and 23Na and 39K of hydrated alkaline metal ions at various temperatures. The relaxation rates for the 17O of H2O showed that the rotational motion of the water molecule is more restricted in the sodium system than that in the potassium system. Arrhenius plots also showed that the activation energy for the relaxation rate of the water molecule is larger in the sodium system. The dependences of the longitudinal relaxation rates for the alkali ions on the DBP concentrations in these systems showed that the sodium ion has an enhanced tendency, over the potassium ion, to interact with the dibutyl phosphate ion and to form ion-aggregates.
    Viscosity measurements showed that the appreciable restriction of the motion of the water molecules in DBP solutions corresponds to a great extent in the aggregation of DBP.
  • Shunichi Fukuzumi, Tomohiro Yorisue
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 3 Pages 715-719
    Published: 1992
    Released: July 14, 2006
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    Electron transfer from various hydroquinone dianions (X-Q2−) to 10-methylacridinium ion (AcrH+) and [Co(tpp)]+ (H2tpp = tetraphenylporphyrin) occurs efficiently in deaerated MeCN to yield 10,10′-dimethyl-9,9′-biacridine [(AcrH)2] and [Co(tpp)], respectively. The electron transfer results in the one-electron or two-electron oxidation of X-Q2−, depending on the one-electron oxidation potentials of X-Q2− and X-Q.
  • Tsuneo Fujii, Toshiaki Mabuchi, Hiroshi Kitamura, Osamu Kawauchi, Nobu ...
    1992 Volume 65 Issue 3 Pages 720-727
    Published: 1992
    Released: July 14, 2006
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    The fluorescence and fluorescence-excitation spectra of 1-naphthol during sol to gel to xerogel transitions of a mixed solution comprising silicon and aluminum alkoxides (Si : Al = 94 : 6) catalyzed by a small amount of NaOH aqueous solution have been observed as a function of time. During the reaction of the system, the spectrum shifted to the red in the first stage and shifted to the blue in the next stage. This behavior reflects the changes of polarity and microviscosity of the matrix surrounding the doped 1-naphthol molecules during the sol to gel to xerogel transitions of the mixed metal alkoxide. The gelation occurred at 10 d. On the other hand, the most remarkable red-shift in the fluorescence spectrum was observed at 9 d. Comparing the fluorescence and fluorescence-excitation spectra of 1-naphthol in typical solvents with those of the sol–gel process, it has become apparent that a part of the doped 1-naphthol molecules in the ground state form a contact ion pair on the surface in cages of the prepared gel.
  • Shuhei Shioji, Kenjirou Tokami, Hideo Yamamoto
    1992 Volume 65 Issue 3 Pages 728-734
    Published: 1992
    Released: July 14, 2006
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    The surface alkoxylation reaction of silicas was investigated under mild reaction conditions with some low-molecular-weight saturated aliphatic alcohols. Silica gels and porous silica glass were treated with liquid alcohols using a Soxhlet extractor below their boiling points. The number of formed alkoxyl groups was examined by both thermal analyses and infrared spectra. It was shown that some of the surface hydroxyl groups were easily esterified to alkoxyl groups, even by contact with the alcohols under mild reaction conditions. The degree of alkoxylation was higher for the silica gels than for porous silica glass. The adsorption isotherms of methanol vapor at room temperature were measured on silica gel samples which were previously activated at various temperatures. The adsorption equilibrium strongly depends on the pretreated temperature. The surface methoxylation reaction took place not only on the surface hydroxyl groups, but also on the siloxane bridges, even at room temperature.
  • Tetsuo Miyazaki, Yoshiteru Fujitani, Masao Shibata, Kenji Fueki, Nobuy ...
    1992 Volume 65 Issue 3 Pages 735-738
    Published: 1992
    Released: July 14, 2006
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    Recoil T-atom reactions have been studied in Xe–H2–D2 mixtures at 77 and 4.2 K. When T atom reactions were caused at 77 K by neutron irradiation at an extremely low dose rate of γ-rays, a large isotope effect (kHT/kDT≈7) on the formation of HT and DT was observed. When T-atom reactions were caused at 77 K by neutron irradiation at a high dose rate of γ-rays, there was no isotope effect (kHT/kDT≈1) on the formation of HT and DT. The production of H and D atoms by γ-irradiation of the Xe–H2–D2 mixtures was studied by ESR spectroscopy at 4.2 K. The significant effect of the dose rate of γ-rays on the HT and DT formation was interpreted in terms of competition between a tunneling reaction of thermal T atoms with H2(D2) and a combination reaction of thermal T atoms with H(D) atoms produced by γ-radiolysis.
  • Takao Sato, Nobuo Tanaka, Hideaki Moriyama, Osamu Matsumoto, Akio Take ...
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 3 Pages 739-745
    Published: 1992
    Released: July 14, 2006
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    The structures of three mimic myoglobins reconstituted with synthesized iron(III) meso-substituted porphyrins have been studied by X-ray crystallography. Although the overall structure of each globin was the same as that of the native, apart from a few terminal residues, the Cα atom of Arg45 in each crystal was displaced by 2.7 Å from that in the native. This large displacement opens a channel for the ligand penetration, formed by His64, Thr67, Val68, and heme. The movement of each porphyrin was estimated from the refined anisotropic temperature factors of its atoms, which showed that the root-mean-squares amplitude of the vibration about the normal to the porphyrin plane was significantly larger than the globin’s movement.
  • Isao Yokoyama, Yoshihisa Miwa, Katsunosuke Machida
    1992 Volume 65 Issue 3 Pages 746-760
    Published: 1992
    Released: July 14, 2006
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    The molecular mechanics simulation of the infrared absorption and Raman spectra of acetic acid in the solution or liquid phase has been carried out by using an empirically estimated force field which includes the equilibrium charges and the charge fluxes as the Coulomb potential parameters. The variation of the observed band widths among different normal modes has been taken into account by introducing the half band width parameters empirically assigned to individual internal coordinates. The half widths of more than 20 bands observed in the infrared absorption and the Raman spectra are well reproduced in terms of five half band width parameters. The thermodynamic properties and the structures of acetic acid monomer and dimer are successfully simulated. The overall features of the simulated spectra of acetic acid are in good agreement with the observed ones.
  • Haruto Muraishi
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 3 Pages 761-770
    Published: 1992
    Released: July 14, 2006
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    Several hydrated alkali silicates, SiO2–Y, SiO2–X2, and another silicate, form as intermediate products of the transformation of amorphous silica to quartz in alkaline solutions containing sodium and/or potassium salts at a temperature below 170 °C. SiO2–X2 (M2Si20O41·xH2O, M = K, Na, x = 8–10) usually appears after the formation of SiO2–Y (Na2Si14O29·xH2O, x = 9–11), and can also be prepared directly from a solution with the pH adjusted to about 9.5 or from a solution containing potassium ion alone. The resulting SiO2–X2 materials are compounds of hydrated sodium-, potassium- and (sodium, potassium)-form silicates. Another silicate precipitates directly from the solutions with the pH adjusted to below 9.5 by use of sodium carbonate and sodium hydrogencarbonate, and the product is a hydrated sodium silicate, Na2Si22O45·xH2O (x = 7–11). The structure and properties of this silicate are the same as that of natural kenyaite which is supposed to be a precursor of chert forming in evaporative alkaline lakes. These synthesized silicates have a layered structure and the interlayer alkali metal ions are exchanged by protons.
  • Yasuko Shimizu, Keiko Taniguchi, Yasuhiro Inada, Shigenobu Funahashi, ...
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 3 Pages 771-776
    Published: 1992
    Released: July 14, 2006
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    Kinetics of zinc(II) ion incorporation into water-soluble N-phenylporphyrins (N-phenyl-5,10,20-tris(4-sulfonatophenyl)-15-phenylporphine: N-PhTPPS3 and N-phenyl-5,10,15,20-tetrakis(4-sulfonatophenyl)porphine:N-PhTPPS4) have been studied spectrophotometrically. The reaction proceeded through two parallel paths; one involving Zn2+ with a rate constant, k, and the other involving ZnOH+ with a rate constant, kOH. The rate constants (25 °C) and activation parameters at I = 0.10 M (NaNO3) were as follows (1 M = 1 mol dm−3): for N-PhTPPS3 k = (2.8 ± 0.1) × 103 M−1 s−1, kOH = (2.1 ± 0.1) × 106 M−1 s−1, ΔH = 54 ± 3 kJ mol−1, ΔHOH = 26 ± 2 kJ mol−1, ΔS = 1 ± 10 J K−1 mol−1, ΔSOH = −37 ± 8 J K−1 mol−1; for N-PhTPPS4 k = (5.3 ± 0.3) × 103 M−1 s−1, kOH = (2.0 ± 0.2) × 106 M−1 s−1, ΔH = 62 ± 4 kJ mol−1, ΔHOH = 34 ± 8 kJ mol−1, ΔS = 35 ± 14 J K−1 mol−1, ΔSOH = −11 ± 28 J K−1 mol−1. The rate of complexation for N-phenyl-substituted porphyrin was slower than that for the open-chain ligands, but much faster than that for the non-N-substituted homologues. This was due to the steric deformation of the porphyrin ring because of the presence of the bulky phenyl group. The ZnOH+ species was much more reactive in comparison to the Zn2+ species. Such a bound-ligand effect could be partly attributed to the labilization of the coordinated water molecules by electron donation from the bound hydroxide.
  • Hiroyuki Nariai, Itaru Motooka, Mitsutomo Tsuhako
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 3 Pages 777-780
    Published: 1992
    Released: July 14, 2006
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    As a part of an investigation on the effect of water vapor on the thermal behavior of cyclo-phosphates, Mn3H2(P4O12)2·9.5H2O Mn3H2(P4m)2·9.5H2O was examined by means of DTA-TG, X-ray analysis, and HPLC-FIA. Mn3H2(P4m)2·9.5H2O lost the water of crystallization at about 145 °C. In a temperature range 165–265 °C, Mn3H2(P4m)2 anhydride decomposed to form oligophosphates(Poligo). At temperatures below 200 °C, the amounts of Poligo were more abundant under humid conditions than under dry conditions. At 265–450 °C, Poligo changed partially into polyphosphates (Ppoly) and insoluble highpolyphosphates(Phigh poly). The dehydration and condensation reactions proceeded faster under dry conditions than under humid conditions, where gradual water evolution was noted over the temperature range of 265 to 450 °C. The stable crystalline Phigh poly, Mn(PO3)2, was produced at temperatures above 450 °C, where the product was not affected by the water vapor.
  • Noriyasu Yasuda, Hisao Kokusen, Yoshiki Sohrin, Sorin Kihara, Masakazu ...
    1992 Volume 65 Issue 3 Pages 781-785
    Published: 1992
    Released: July 14, 2006
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    The extraction behavior of divalent metals (M2+) with dihydrobis(1-pyrazolyl)borate ligand (H2B(pz)2) has been studied. Divalent transition metals form [M{H2B(pz)2}2] chelates readily and are extracted into the organic phase. The extraction constants of the first-row transition metals increase in the order Mn(II) < Fe(II) < Co(II) < Ni(II) < Cu(II) > Zn(II), which is in accordance with the Irving and Williams’ order for complex stability. Although Be2+ is slightly extracted by H2B(pz)2, Mg2+, Ca2+, Sr2+, and Ba2+ are not extracted, whether a synergistic agent such as trioctylphosphine oxide and tetrabutylammonium chloride is added or not. The characteristics of H2B(pz)2 in the extractability of metal ions are ascribed to that the basicity of coordinating nitrogen atoms is increased by negative charge of the molecule and inductive effect of the boron atom, and that adduct formation is restricted by the steric hindrance.
  • Hideki Masuda, Tamotsu Sugimori, Takamitsu Kohzuma, Akira Odani, Osamu ...
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 3 Pages 786-793
    Published: 1992
    Released: July 14, 2006
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    With a view to understanding the factors affecting the chemical properties of the copper sites in proteins, model copper(II) complexes of two multidentate ligands with nitrogen and sulfur atoms, 1,5-bis(2-pyridylmethylamino)-3-thiapentane (pmtp) and 2,6-bis(2,6-dithiaheptyl)pyridine (dthp), have been isolated as [Cu(pmtp)][Cu(pmtp)ClO4](ClO4)3 (1) and [Cu(dthp)(NO3)2] (2), respectively, and studied by X-ray diffraction, spectroscopic, and electrochemical methods. Complex 1 crystallizes in space group P21/a of the monoclinic system with four [Cu(pmtp)]2+ ions and four [Cu(pmtp)(ClO4)]+ ions in a cell of dimensions a = 24.180(7), b = 31.855(7), c = 9.760(3) Å, and β = 143.84(1)°. The coordinations around the coppers in the two independent complexes are square-pyramidal and octahedral, respectively, with an amine nitrogen, two pyridine nitrogens, and a thioether sulfur at the equatorial positions (eq) and an amine nitrogen (and a perchlorate oxygen in addition in the octahedral complex) at the axial position(s) (ax); Cu–Neq = 1.991(10), 2.001(14), and 2.009(9) Å, Cu–Seq = 2.353(6) Å, Cu–Nax = 2.276(8) Å for [Cu(pmtp)]2+, and Cu–Neq = 1.994(7), 2.002(6), and 2.013(14) Å, Cu–Seq = 2.355(6) Å, Cu–Nax = 2.306(10) Å, Cu–Oax = 2.698(14) Å for [Cu(pmtp)(ClO4)]+. Complex 2 crystallizes in space group P21/c of the monoclinic system with four [Cu(dthp)(NO3)2] molecules in a cell of dimensions a = 18.492(5), b = 14.375(3), c = 8.554(2) Å, and β = 101.19(2) Å. The coordination around copper is distorted trigonal-bipyramidal with two thioether sulfurs and a nitrate oxygen in the trigonal plane and a pyridine nitrogen and a nitrate oxygen at the axial positions; Cu–Seq = 2.344(2) and 2.402(2) Å, Cu–Oeq = 2.244(6) Å, Cu–Nax = 1.982(6) Å, Cu–Oax = 1.927(5) Å. The structures of these complexes in aqueous solution were concluded to be square-pyramidal from ESR and electronic spectra. Their reduction potentials (E1⁄2 vs. NHE) were +0.062 V for 1 in CH3CN with one coordinated S atom and +0.678 V for 2 in CH2Cl2 with two coordinated S atoms. The higher E1⁄2 value for 2 has been interpreted as due to the presence of the two coordinated sulfur atoms and the flexibility of the ligand which can accomodate the structural changes accompanying the Cu(II)/Cu(I) redox reaction.
  • Ken-ichi Okamoto, Toshiaki Yonemura, Takumi Konno, Jinsai Hidaka
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 3 Pages 794-798
    Published: 1992
    Released: July 14, 2006
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    The novel mononuclear, dinuclear, and trinuclear cobalt(III) complexes with D-penicillaminate(D-pen), ΛDDD-fac(S)-[Co(D-pen-N,S)3]3−, ΛDDD-[Co{Co(D-pen-N,S)3}(dien)], ΛDDD-[Co{Co(D-pen-N,S)3}(D-pen-N,O,S)]2−, and ΛDDDΔDDD-[Co{Co(D-pen-N,S)3}2]3− were prepared. These complexes were characterized from their electronic absorption, CD, and 13C NMR spectra. These complexes formed selectively each one isomer. The stereoselectivity for the D-pen complexes is discussed in comparison with that of the corresponding L-cys ones. The D-pen polynuclear complexes exhibited characteristic absorption spectral behaviors in the visible region. The 13C NMR spectral behaviors for the D-pen complexes are connected with those of the corresponding L-cys ones.
  • Sadayuki Himeno, Toshiyuki Osakai, Atsuyoshi Saito, Toshitaka Hori
    1992 Volume 65 Issue 3 Pages 799-804
    Published: 1992
    Released: July 14, 2006
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    Monovanadium derivatives of 12-molybdosulfate(VI) and 18-molybdodisulfate(VI), [S(VMo11)O40]3− and [S2(VMo17)O62]5−, have been prepared as tetrabutylammonium (n-Bu4N+) salts from a Mo(VI)–V(V)–H2SO4–CH3CN system. Both mixed molybdosulfate(VI) comlexes were characterized by their IR and UV spectra and their voltammetric behaviors. These mixed complexes are stable in nonaqueous solutions. In a 90% (v/v) CH3CN–0.1 M (M = mol dm−3) HClO4 system, the [S(VMo11)O40]3− anion transforms spontaneously into 12-molybdovanadate(V), whereas the [S2(VMo17)O62]5− anion is stable. In a 90% (v/v) CH3CN–0.5 M HClO4 system, on the other hand, both mixed complexes change into 18-molybdodisulfate(VI), [S2Mo18O62]4−.
  • Hiroshi Nonoguchi, Kazuo Yamamura, Iwao Tabushi, Tai-ichi Higuchi, Ken ...
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 3 Pages 805-811
    Published: 1992
    Released: July 14, 2006
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    The CHCl3 guest molecules of the 2,11,20,29-Tetramethyl-2,11,20,29-tetraaza[3.3.3.3]paracyclophane (1) inclusion complex were completely replaced by CH2BrCl when [1·CHCl3] powder simply made contact with gaseous CH2BrCl molecules. This guest exchange in the crystalline phase was confirmed by 1H NMR, GLPC, and X-ray analysis. The guest exchange was found to proceed in a biphasic manner, viz., (a) a “slow” exchange approaching a guest composition of 65% CHCl3 / 35% CH2BrCl followed by (b) a “rapid” exchange. The latter abrupt increase of the exchange rate was most reasonably attributed to a change of in crystal structure, based on the X-ray diffraction pattern of a fully guest-exchanged crystal (Type I) which was found to be very similar to that of a Type II crystal of [1·CH2BrCl].
  • Kazuaki Ito, Katsuhiro Saito, Kensuke Takahashi
    1992 Volume 65 Issue 3 Pages 812-816
    Published: 1992
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    Simple heating of mixtures of N-arylcycloheptatriene-1-imines and acyl chlorides in the presence of an excess amount of triethylamine afforded 1-azaazulen-2(1H)-ones in high yields. The intermediacy of the [8+2] cycloadducts between the 2,4,6-cycloheptatriene-1-imines and ketenes were confirmed by their isolations. Analogous results were obtained with tropone hydrazones.
  • Yasufumi Tamai, Pu Qian, Ken’ichi Matsunaga, Sotaro Miyano
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 3 Pages 817-823
    Published: 1992
    Released: July 14, 2006
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    Optically active polymethacrylates 6 and 8, which have pendant axially dissymmetric 1,1′-binaphthalene moiety, were synthesized by radical polymerization of (S)-2-methacryloyloxy- and (S)-2-(3-methacryloyloxypropoxy)-2′-methoxy-1,1′-binaphthalene, respectively. Specific rotation and CD spectrum of 6 are rather different from those of the model compound 2-(2,2-dimethylpropanoyloxy)-2′-methoxy-1,1′-binaphthalene (7), while the chiroptical properties of 8 are almost the same as those of the corresponding model compound. The difference of the chiroptical properties between 6 and 7 was attributed to the difference of the dihedral angles between the naphthalene planes of the 1,1′-binaphthalene skeleton. The polymethacrylates 6 and 8 were coated on a spherical silica gel to give HPLC chiral stationary phases (CSP-6 and CSP-8). These CSPs differentiated several enantiomeric 1-aryl-1-alkanols and 1,2-diols as the 3,5-dinitrophenylcarbamates, CSP-8 showing better resolution than CSP-6. Furthermore, (S)-2-(5-carboxypentyloxy)-2′-methoxy-1,1-binaphthalene, a model compound of 8, was prepared and covalently bonded to an aminopropylsilanized silica gel to afford CSP-16, which also resolved these racemates. Thus, the chiral discriminating ability of the polymethacrylate 8 would be based not on the secondary and/or higher-ordered structure, but mainly on the interaction between the individual 1,1′-binaphthalene units of 8 and the racemates.
  • Michio Higashijima, Shigeo Nishimura
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 3 Pages 824-830
    Published: 1992
    Released: July 14, 2006
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    The catalytic hydrogenation of p-cresol with commercial Pd on active carbon (Pd–C), water-washed Pd–C (Pd–C–N), acid-treated Pd–C (Pd–C–A), and base-treated Pd–C (Pd–C–B) has been kinetically studied in cyclohexane as a solvent under 0.15–8.0 MPa hydrogen pressure at 80°C. Under each reaction condition, the hydrogenation rate constants for the cresol and the ketone intermediate, k1+k3 and k2, respectively, the relative reactivity of the ketone to the cresol (K) and the ratio of the adsorption coefficient of the ketone to that of the cresol (b2/b1) were determined on the basis of a Langmuir–Hinshelwood model. Regardless of the difference in the nature of the catalysts, hydrogenations with these catalysts always gave high selectivities of 0.85–1.0 for the formation of the ketone intermediate, and small values of 0.014–0.62 for the relative reactivity (K). The small values of K over Pd–C and Pd–C–B were shown to be mostly due to the small values of k2/(k1+k3). In contrast, even smaller values of K over Pd–C–N and Pd–C–A were found due to a great difference in the strength of adsorption between the cresol and the ketone intermediate. In general, both the values of K and k2/(k1+k3) increase with increasing hydrogen pressure. All of the experimental results show that both the alkaline impurities associated with catalyst preparation and the hydrogen pressure are the most important factors affecting the formation of the ketone intermediate.
  • Shunichi Fukuzumi, Yoshihiro Tokuda
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 3 Pages 831-836
    Published: 1992
    Released: July 14, 2006
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    Photoreduction of nitrobenzene derivatives by 10-methyl-9,10-dihydroacridine (AcrH2) occurs efficiently in the presence of perchloric acid in acetonitrile containing H2O (0.50 mol dm−3) to yield the corresponding six-electron reduced products (aniline derivatives) and 10-methylacridinium ion efficiently. The initial two-electron reduction of PhNO2 to PhNO by AcrH2 in the six-electron reduction of nitrobenzene (PhNO2) is started by electron transfer from AcrH2 to the n,π* triplet state (3PhNO2*), followed by acid-catalyzed thermal reduction of PhNO to PhNHOH by AcrH2 and the subsequent photoreduction of PhNHOH to PhNH2 by AcrH2.
  • Kyoji Tsubakiyama, Kohji Miyagawa, Kiyotaka Kaizaki, Masahide Yamamoto ...
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 3 Pages 837-845
    Published: 1992
    Released: July 14, 2006
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    The photochemical reactions of 4-acylstyrenes (1ae; acyl = acetyl, benzoyl, 1-naphthoyl, 2-naphthoyl, and 9-phenanthrylcarbonyl, respectively) were investigated, and their excited state behavior and photoreactivities are discussed in relation to the aryl ketone structures. Photoirradiation of 1ae in benzene gave two isomeric cyclodimers of trans- and cis-1,2-bis(4-acylphenyl)cyclobutanes(2ae and 3ae) as main products, accompanied by the formation of some oligomers and polymers. The fractions of the trans-form in the cyclodimers were ca. 80%; this indicated that the cyclodimerization proceeded via the π,π* triplet state. The quantum yields of the photodimerization for 1ae were almost the same irrespective of the acyl substituents (Φ = 0.03–0.04 at [1ae] = 0.1 mol dm−3). Phosphorescence spectra of 1c (τ = 0.48 s) and 1d (τ = 0.91 s) observed in a rigid solution at 77 K, which coincided with those of the respective model aryl ketones, were ascribed to the low-lying excited π,π* triplet states localized on the naphthalene moiety of the molecules. Phosphorescence emissions of 1a and 1b could not be detected. The transient absorption spectrum of 1d (τ = 23 ns) observed in a fluid solution at 293 K was tentatively assigned to the π,π* triplet state mainly localized on the styrene moiety of the molecule. The photoreaction mechanism is discussed in terms of the intramolecular triplet energy transfer.
  • Akikazu Matsumoto, Hiroyuki Watanabe, Takayuki Otsu
    1992 Volume 65 Issue 3 Pages 846-852
    Published: 1992
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    Itaconates containing a 1-adamantyl or a 3,5-dimethyl-1-adamantyl ester group were prepared and polymerized in the presence of a radical initiator. The polymerization reactivity has been investigated in relation to the structure of ester alkyl groups of the monomer. It has been clarified that the adamantyl-containing polyitaconates show high thermal stability, i.e., high glass transition temperatures and decomposition temperatures. The relationship between polymer structures and thermal properties of polymers from some α- and β-substituted acrylic esters, i.e., acrylates, methacrylates, crotonates, fumarates, and itaconates was discussed.
  • Yoriko Sonoda, Kyoji Kaeriyama
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 3 Pages 853-857
    Published: 1992
    Released: July 14, 2006
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    Poly(2,5-diheptyl-1,4-phenylenevinylene) (1) was prepared by the sulfonium salt pyrolysis procedure. Tough films of 1 were obtained by pyrolysis of its sulfonium salt precursor film. Due to flexible side chains, 1 was soluble in organic solvents such as chloroform. The molecular weights were Mn = 3.8−4.7 × 104 and Mw = 1.4−1.8 × 105. The ratio of trans to cis olefinic units was found to be 93 : 7 from the 1H NMR spectrum. Two arylmethylene peaks suggested that there were two kinds of stereochemically different methylene groups. Although the peak energy in the absorption spectra was almost identical to those of poly(1,4-phenylenevinylene) (PPV), the electrical conductivity of 1 was much lower than that of PPV.
  • Norihiro Ikeda, Norihiko Sanefuji, Koji Abe, Natsuko Todoroki, Makoto ...
    1992 Volume 65 Issue 3 Pages 858-863
    Published: 1992
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    The miscibility of dodecyltrimethylammonium chloride (DTAC) and dodecylammonium chloride (DAC) in the adsorbed film at water/air interface and in the micelle was investigated by measuring the surface tension of the aqueous solution of surfactant mixture as a function of the total molality and composition of surfactants. The compositions of surfactants in the adsorbed film and micelle were evaluated by use of the thermodynamic equations developed previously. The results indicated that DTAC and DAC molecules mix slightly nonideally in the adsorbed film and micelle. Furthermore, the composition of DAC in the micelle was found to be remarkably smaller than that in the adsorbed film at the critical micelle concentration. It was concluded that the bigger hydrophilic group of DTAC is geometrically favorable for the micelle formation.
  • Tisato Kajiyama, Yushi Oishi, Motoko Uchida, Naoaki Morotomi, Jun-ichi ...
    1992 Volume 65 Issue 3 Pages 864-870
    Published: 1992
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    The melting temperature, Tm and the crystalline relaxation temperature, Tαc of fatty acid monolayers on the water surface were evaluated by a combination of two kinds of measurements, the subphase temperature, Tsp dependence of monolayer modulus based on a π-A isotherm and also, the Tsp dependence of the electron diffraction, ED patterns of monolayer. Tms of myristic, palmitic, and stearic acid monolayers were evaluated to be 278, 301, and 317 K, respectively, on the basis of both apparent decrease in the Tsp vs. modulus curve and the change of the ED pattern from a crystalline Debye ring to an amorphous halo. The crystalline relaxation process corresponds to a change from elastic to viscoelastic characteristics in a crystalline phase due to a considerable contribution of anharmonic thermal molecular vibration. Tαcs of palmitic and stearic acid monolayers were evaluated to be 291 and 298 K, respectively, from both apparent decrease in the Tsp dependence of modulus and appearance of the break in the thermal expansion coefficient of crystalline lattice constant. This break may be attributed to a remarkable increase in contribution of the anharmonic term with respect to the intermolecular potential energy. The magnitude of Tm and Tαc of monolayers on the water surface is an important factor to decide the structure or aggregation state in the crystalline and amorphous monolayers and also, the formation process of a large-area monolayer, that is, the fusion or sintering behavior among crystalline monolayer domains.
  • Shoji Imai, Yasuhisa Hayashi
    1992 Volume 65 Issue 3 Pages 871-875
    Published: 1992
    Released: July 14, 2006
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    In the graphite furnace atomic absorption spectrometry of gold, signals with a single peak were observed with a pyrolytic graphite (PG) furnace, while signals with a shoulder on the tailing edge were observed with a nonpyrolytic graphite (NPG) furnace. A thermal shift of the atomic absorption signals for gold occurs in response to changes in the concentration of ascorbic acid without any loss for each furnace. When the pre-pyrolysis of a 5% (m/V) ascorbic acid solution was carried out at 1270 K, although the background signal due to the release of amorphous carbon was not observed, a thermal shift of the gold signal was confirmed. At a pre-pyrolysis temperature over 1460 K, the peak absorbance was reduced by increasing the pre-pyrolysis temperature, while absorbance at the position of the signal for gold only was increased. The values of the Arrhenius activation energy for the desorption of gold were obtained to be 60 ± 2 kcal mol−1 for gold only, 93 ± 3 kcal mol−1 for gold with 5% (m/V) ascorbic acid and 99 ± 2 kcal mol−1 after a pre-pyrolysis of ascorbic acid at 1270 K.
  • Yoshimasa Hoshino, Fumiyo Okuyama, Akimichi Nanba, Kunio Shimizu, Gen ...
    1992 Volume 65 Issue 3 Pages 876-881
    Published: 1992
    Released: July 14, 2006
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    Two mixed-ligand complexes, [Ru(hfac)2(en)] and [Ru(hfac)(en)2]PF6 (en = ethylenediamine and hfac = hexafluoroacetylacetonate ion), were synthesized. The oxidative dehydrogenation of their en ligand was studied in acetonitrile solutions. Each complex underwent a Nernstian one-electron oxidation at platinum electrodes. The resultant ruthenium(III) species was converted through a series of slow homogeneous reactions into the corresponding 1,2-diiminoethane ruthenium(II) species. Voltammograms recorded during the course of the reactions suggested the presence of 2-amino-1-iminoethane ruthenium(II) intermediates.
  • Kunihiro Watanabe, Atsushi Takakuwa, Kazuo Fueki
    1992 Volume 65 Issue 3 Pages 882-885
    Published: 1992
    Released: July 14, 2006
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    The determination method of the average valence of copper in a Y–Ba–Cu–O superconductor has been investigated. Spectrophotometry was introduced to the iodometry considered to be a conventional method in order to decrease the amount of sample used. The iodine liberated by the reaction between Cu2+ and/or Cu3+ and I ions was extracted into chloroform with Zephiramine (Zeph+Cl) as a Zeph+I3 ion pair complex. The extraction of I3 enhanced the reproducibility. The effect of the HCl concentration was significant. The sample was dissolved with 5 ml of a 0.1 M (M = mol dm−3) HCl solution by means of ultrasonic irradiation. The employed method decreased the amount of consumed sample down to 4 mg. The modified method, using cuproine, decreased the amount down to 2 mg.
  • Takashi Yamane, Yoshiaki Ito, Tamaichi Ashida, Kazuhiko Hashimoto, Hir ...
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 3 Pages 886-891
    Published: 1992
    Released: July 14, 2006
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    The crystal structures of N-benzoyl-8-oxa-6-azabicyclo[3.2.1]octan-7-one (Bz-BOL), N-benzoyl-ε-caprolactam (Bz-CLA), and N-benzoyl-2-pyrrolidone (Bz-PYR) have been determined in order to clarify the relation between their structures and reactivities by N-benzoyl substitution. Bz-BOL belongs to monoclinic, P21/n, a = 10.372(1), b = 23.155(5), c = 9.737(4) Å, β = 100.92(2)°, Z = 8. Bz-CLA is monoclinic, P21/c, a = 9.234(2), b = 8.532(3), c = 15.097(3) Å, β = 92.42(2)°, Z = 4. Bz-PYR is monoclinic, P21/n, a = 10.801(3), b = 6.020(1), c = 15.082(3) Å, β = 97.95(2)°, Z = 4. The final R-values are 0.049 for 2867 reflections of Bz-BOL, 0.069 for 1634 reflections of Bz-CLA, and 0.053 for 1175 reflections of Bz-PYR. In these compounds the orientaion of the benzoyl moiety against the lactam moiety is essentially the same, and the phenyl group is nearly perpendicular to the lactam-amide plane. The C–N bond distance of the lactam moieties in benzoyl derivatives is significantly prolonged, as compared with that in the original lactams, though the C–N distance is apparently equal to that of acyl moieties in these benzoyl derivatives. This suggests that the C–N bond of the lactam moieties in the benzoyl derivatives is weakened by acylation and is easily broken by a nucleophilic attack, as compared with that of the original lactams.
  • Hiroshi Miura, Kazuo Oki, Hisayoshi Ochiai, Hiroshi Higuchi, Michio Te ...
    1992 Volume 65 Issue 3 Pages 892-896
    Published: 1992
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    A selective CVD system used to deposit the central metal of a volatile complex preferentially on catalytically active substrate surfaces was examined. Copper(II) acetylacetonate was vaporized in a flow of hydrogen and decomposed on Ni, Pd, and Al plates in order to deposit metallic copper. When a Ni plate was used as the substrate, deposition of metallic copper occurred at temperatures in the range 13O–180 °C only on the substrate surfaces. The formation of an ultrathin film of Cu of uniform thickness was confirmed. On a Pd substrate, the formation of an ultrathin Cu film of uniform thickness was also observed. On an Al substrate, however, deposition occurred nonselectively at temperatures above 160 °C, not only on the substrate surface, itself, but also on the wall of the glass tube as well as the quartz wool surrounding the Al plate. In addition, the formation of fine particles of Cu, instead of thin film, was found to exist on the substrate. Because the deposition of Cu took place on catalytically active surfaces selectively, the deposition was considered to proceed by a catalytic hydrogenation of the C=O bond of the ligand, thus detaching it from the Cu ion and allowing it to decompose the complex and deposit Cu metal.
  • Yoshiharu Usui, Noriyo Shimizu, Satoshi Mori
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 3 Pages 897-902
    Published: 1992
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    The formation efficiencies of singlet oxygen for the oxygen quenching in excited singlet of aromatic hydrocarbons; A and for the quenching in the triplet T1; B were estimated. The hydrocarbons were classified into three types: (i) A = 1 and B = 1 for dicyanoanthracene i.e., total 200% efficiency, (ii) A ≈ 0.3 and B = 1 for anthracene, (iii) A ≈ 0 and B = 1 for pyrene, as examples. It is suggested that the energy levels of T2 and a dissociative exciplex; (T11Δg) correlated to A and B values from the energetic considerations.
  • Hiroshi Kashiwagi
    1992 Volume 65 Issue 3 Pages 903-905
    Published: 1992
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    The number of spins of coexisting two-radical species on an HY-type zeolite (HY) in the absence of a solvent were independently determined with electron paramagnetic resonance spectroscopy. The coexistence of both donors and acceptor molecules on HY gave rise to the increasing numbers of both cations and anion radicals and to their adsorption-order dependence. The numbers of coexisting cations and anion radicals were independent of, while their maximal numbers of spins were dependent on, the spin-generating abilities of the donors and acceptors. Futhermore, a small enhancement of radicals and a remarkable adsorption-order dependence arose in a solvent-free ternary system comprising HY and either two donors or two acceptors.
  • Atsuko Tomishima, Yutaka Takakura, Yukihiro Yokoyama, Katsuhiro Saito, ...
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 3 Pages 906-908
    Published: 1992
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    The 1H NMR spectra of the title compound dissolved in a nematic phase of ZLI1167 have been analyzed, and the structure of the proton skelton has been determined.
  • Akira Tsuchida, Hiroshi Takamura, Masahide Yamamoto, Bong Lee, Tomiki ...
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 3 Pages 909-910
    Published: 1992
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    The charge-resonance band of the 9,9′-trimethylenedianthracene radical cation () was observed at 1550 nm by laser photolysis in the near-IR region. Two anthracene chromophores of were found to take a full-overlap conformation; a clear relationship between the dimer stabilizaiton energy and the aromatic ring size was shown.
  • Izuo Aoki, Masahiko Tuyuki, Kunihiro Watanabe
    1992 Volume 65 Issue 3 Pages 911-913
    Published: 1992
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    In the presence of fluoride ions, aluminium reacts with N-salicylideneethylenediamine to form fluorescent Schiff base complexes. A flow-injection analysis system based on this reaction has been developed for a determination of the fluoride ions at the ppm level. By measuring the fluorescence intensities, the number of fluoride ions could be selectively determined over the range 0.15–10 ppm; 40 samples could be analyzed per hour. The proposed system was applied to an analysis of the fluoried ion in river water.
  • Hirotoshi Nakabayashi
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 3 Pages 914-916
    Published: 1992
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    Both Lewis and Brönsted acid sites were found on the surface of TiO2–SiO2 mixed oxide, thouth no Brönsted acid sites were detected on the surface of pure TiO2 and SiO2. While on the surface of TiO2–Al2O3 mixed oxide, no Brönsted acid sites were generated. The rate of isomerization of 1-butene was found to be enhanced on the Brönsted acid sites formed on the TiO2–SiO2 mixed oxide.
  • Hiroyuki Miyake, Yoshitane Kojima, Tetsushi Yamashita, Akio Ohsuka
    1992 Volume 65 Issue 3 Pages 917-919
    Published: 1992
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    In chloroform, cyclo(G-eLL-G)2 exists as an equilibrium of two conformers and aggregates from the monomer to the oligomer with an increase in the peptide concentration, owing to the intermolecular hydrogen bonds formed between the amide hydrogen and the oxygen.
  • Katsumi Yonemoto, Isao Shibuya, Yoichi Taguchi, Tohru Tsuchiya, Masahi ...
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 3 Pages 920-922
    Published: 1992
    Released: July 14, 2006
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    N-(Substituted formyl)dialkylamino(thioxo)methanesulfenamides (R2NCSSNHCOR′ 3: R = alkyl, R′ = alkyl, dialkylamino, alkoxy, and heterocyclic substituent) were treated with a strong acid (HBF4 or HClO4) in Ac2O to afford 1,4,2,-dithiazolium salts (7) and/or 3,5-bis(dialkyliminio)-1,2,4-trithiolanes (9). The reactivity is markedly dependent on the nature of substituents (NR2 and R′) and the acid used. For R′ = MeO, the sulfenamides reacted successively with NaH and p-toluenesulfonyl chloride to give methyl bis(dialkylthiocarbamoylthio)carbamates (10). The mechanisms for the formation of 9 and 10 are discussed.
  • Shinichi Motoki, Takaya Sakai, Yoshihisa Matsuo, Shunichi Kametani, Ta ...
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 3 Pages 923-925
    Published: 1992
    Released: July 14, 2006
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    The cycloaddition reaction of 3-styryl-1,2-thia phosphole 2-sulfide and 1,5-diphenyl-2,4-pentadiene-1-thione derivatives generated by the thermolysis of 5,6-distyryl-3,8-diaryl-2,9-dithia-1-phosphabicyclo[4.3.0]nona-3,7-diene 1-sulfides have been described. Methacrylonitrile, methyl methacrylate, α-methylstyrene, norbornene, methyl acrylate, styrene, and mehyl vinyl ketone afforded the cycloadducts or their rearranged products with the thiaphosphole 2-sulfides, whereas diethyl azodicarboxylate, dimethyl acetylenedicarboxylate, and N-(p-methoxyphenyl)maleimide gave the cycloadducts with the thioketone.
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