Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
Volume 67 , Issue 2
Showing 1-49 articles out of 49 articles from the selected issue
  • Toshihiro Kondo, Ramesh C. Ahuja, Dietmar Möbius, Masamichi Fujih ...
    1994 Volume 67 Issue 2 Pages 315-320
    Published: 1994
    Released: July 11, 2006
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    In order to estimate the potential difference of the electrical double layer formed in heterogeneous Sensitizer (S)/Electron Donor (D) Langmuir–Blodgett (LB) films, the surface potentials of the constituent monolayers were measured simultaneously with the π–A isotherms. The S monolayer was a mixed [Ru(bpy)3]2+ complex monolayer with a long alkyl fatty acid, while the D monolayer was one of three kinds of ferrocene monolayers with different signs of the hydrophilic head groups and with the same redox potential. The formation of the potential difference between the charged head group of the amphiphile and its counterion at the water-air interface was confirmed; those values were consistent with the electrical double-layer effect on the luminescent lifetime of [Ru(bpy)3]2+ in the S monolayer in contact with the D monolayer.
  • Refat Abdel-Hamid, Ahmed A. El-Samahy, Mostafa K. M. Rabia, Norman Tay ...
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 2 Pages 321-325
    Published: 1994
    Released: July 11, 2006
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    The electrode mechanism of trans-dicarbonyl phosphine complexes of molybdenum(I), trans-[Mo(CO)2(P-P)2]PF6 [where P-P = ph2PCH2CH2Pph2(dppe), or ph2PCH=CHPph2 (dppen)] was investigated by cyclic voltammetry and convolution and deconvolution potential sweep voltammetry in 0.1 mol dm−3 TBAP/CH2Cl2 solution at a platinum electrode. The complexes are both oxidized and reduced in one-electron processes. The oxidation and reduction processes are follows a well-defined ECirrev mechanism. Digital simulation and comparison with the experimental cyclic voltammetric results was used for determination of homogeneous and heterogeneous rate constants values.
  • S. Patnaik, M. Seshasayee, G. Aravamudan, Hitoshi Ohtaki
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 2 Pages 326-331
    Published: 1994
    Released: July 11, 2006
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    A structural investigation using an X-ray RDF (radial distribution function) technique was carried out for a glass of composition 50AgI–25Ag2O–25MoO3 (in mole% units). Results indicated the presence of strong Ag–I interactions at rAg–I = 287 pm and the average number of iodine atoms around an Ag atom, nAg–I was 0.77. Two Ag–O interactions characterized by rAg–O = 197 pm, nAg–O = 1.8 and rAg–O = 234 pm, nAg–O = 2.6 were also observed. The structural parameters of the glass former MoO3 were given as rMo–O = 198 pm and nMo–O = 5.5. The results showed that AgI was dispersed in the glassy matrix.
  • Takayuki Sano, Thoru Nakatsuka, Katsuaki Inoue
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 2 Pages 332-341
    Published: 1994
    Released: July 11, 2006
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    To clarify the mechanism of polymer complex formation between counter-charged polymers, kinetic and equilibrium experiments concerning the complexation of poly(L-α-glutamic acid) (PGA) with poly (L-α-lysine) (PLL) were performed at around pH 5.5 by the stopped-flow method. The reaction kinetics observed with electric conductivity detection and direct proton detection using the hydrogen ion-sensitive field-effect transistor suggests that the complex formation between these polymers proceeds through two processes of a fast proton release within 10 ms and a slow proton uptake within a few seconds. Further experiments using the various chain lengths of PGA and a variety of combinations of polymers and their counter-charged small ion, (e.g., PGA and amines or metal ions, PLL and carboxylic acids) have revealed that slow proton uptake in their complex formation is specific for a system which includes both a polymer and its counter-charged ions of divalent or more, and that this proton uptake is due to rearrangement of the polymer after fast electrostatic binding as a cooperative process.
  • Kikuko Hayamizu, Shuji Okada, Seiji Tsuzuki, Hiro Matsuda, Atsushi Mas ...
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 2 Pages 342-345
    Published: 1994
    Released: July 11, 2006
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    The 13C NMR spin-lattice relaxation times and ESR spectra were measured for a polydiacetylene obtained by the solid-state polymerization of a tetrayne with n-C14H29 alkyl substituents (14-4A-14). Poly(14-4A-14) has two different side chains. One side chain contains two conjugated acetylenic bonds directly bound to the main backbone conjugated system; the other is an alkyl chain. Although the unpaired electron density of poly(14-4A-14) measured by ESR is less than that in trans-polyacetylene, paramagnetic effects may contribute to the long 13C relaxation times of unsaturated carbons, which provides insight concerning the π-electron structure on the conjugated system.
  • Yung-Dae Ma, Akihiko Takada, Makoto Sugiura, Takeshi Fukuda, Takeaki M ...
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 2 Pages 346-351
    Published: 1994
    Released: July 11, 2006
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    n-Alkyl 1-O-β-D-cellobiosides with an alkyl length ranging from 7 to 18 in carbon number m were synthesized, and their thermal properties were studied in comparison with those of the already-known monosaccharide homologues, n-alkyl 1-O-β-D-glucopyranosides. The cellobiosides were found to exhibit a thermotropic mesophase at higher temperatures than the glucopyranosides. Depending on m and thermal history, the cellobiosides showed various textures such as homeotropic, transient bâtonnets, polygonal, and fan-shaped textures. Like in the case of the monosaccharide homologues, the difficulty of aligning the samples prohibited a full classification of the mesophase, but the X-ray diffractograms of the unaligned cellobiosides indicated that their mesophase belongs to smectic A(or less possibly, smectic C). The m dependence of the lamella thickness was much weaker than (about half) that of the monosaccharide homologues. Possible molecular arrangements of the cellobiosides in the mesophase were presented.
  • Masao Sakurai, Kunio Nakamura, Nobuo Takenaka
    1994 Volume 67 Issue 2 Pages 352-359
    Published: 1994
    Released: July 11, 2006
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    The ultrasonic velocities in dilute alcoholic solutions of water have been measured in the temperature range from 5 to 45 °C. The solvent alcohols used were methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, 2-methyl-2-propanol, 1-pentanol, and 2-methyl-2-butanol. In addition, the densities of 2-butanol and 2-methyl-1-propanol solutions of water were also measured. The apparent molar volumes and apparent molar adiabatic compressions of water in these alcohols have been evaluated. The limiting partial molar quantities are less than the molar quantities of pure water; this phenomenon is generally more pronounced for lower-chain or branched-chain alcohols. The results are discussed in connection with the hydrogen-bonding interactions, that is, the self-association of the solvent alcohols and the alcohol–water interactions.
  • Kanna Sakai, Iwao Watanabe, Yu Yokoyama
    1994 Volume 67 Issue 2 Pages 360-362
    Published: 1994
    Released: July 11, 2006
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    The photoelectron-emission threshold energies were determined for aqueous and alcoholic solutions of potassium hydroxide and potassium metal. The energies correspond to the vertical ionization potentials of the solutes. The results are in accord with the fact that in alcohol-rich solutions the hydroxide ion reacts with alcohol to produce the alkoxide ion. The threshold energy for the alkoxide ion reflects the ionization potential of the alkoxide ion in a vacuum and the solvation effect. The difference in the ionization potential in a vacuum and in a solution, which is due to the solvation effect, was found to correlate with the acceptor number of the solvent.
  • Hideki Matsui, Akihiro Yoshino, Kensuke Takahashi
    1994 Volume 67 Issue 2 Pages 363-367
    Published: 1994
    Released: July 11, 2006
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    Temperature-dependent 1H NMR chemical shifts of the two title carbanions have been measured in three solvents and with three counter ions. The equilibria between two types of ion pairs of the carbanions have been discussed in terms of solvent, counter ion, and temperature.
  • Tetsuya Hosono, Hiroshi Okochi, Manabu Igawa
    1994 Volume 67 Issue 2 Pages 368-374
    Published: 1994
    Released: July 11, 2006
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    Fogwater had been observed for 4.5 years from July 1988 to December 1992 at the midslope of Mt. Oyama at the southwest of the Kanto plains. Rainwater, aerosol, and gases had been also collected and analyzed at the fog sampling station to investigate the characteristics and acidification mechanism of fogwater. The pH of fogwater ranged from 2.61 to 7.00 and the fog with very low pH values and high ion and aldehyde concentrations were frequently observed in spring and summer. The fogwater at the site was acidified primarily by nitric acid gas absorbed in fogwater and the acid fraction of most of the fogwater ranged from 0.3 to 0.01. The acidity of fogwater is controlled by the amount of the acidic pollutants in the atmosphere, the concentrations of the neutralizing components for the acidic fogwater, primarily NH3 gas concentration, the liquid water content in air, and the distance between the sampling station and the lowest altitude of the fog in upslope fog.
  • Masashi Kunitake, Kenji Nasu, Osamu Manabe, Naotoshi Nakashima
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 2 Pages 375-378
    Published: 1994
    Released: July 11, 2006
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    Novel amphiphiles with π-conjugated electroactive groups, 1-methyl-4-[2-[4-[2-(4-pyridyl)vinyl]phenyl]vinyl]pyridinium perchlorate (1), and 1-methyl-4-[2-[4-[2-(4-quinolyl)vinyl]phenyl]vinyl]quinolinium perchlorate (2), were designed and synthesized. Both compounds formed expanded monolayers at air–water interfaces. The monolayers transferred on gold disk electrodes at 25 mN m−1 by the Langmuir–Blodgett technique (horizontal lifting method) show one electron reduction/oxidation couple: Epa = −0.86 V, Epc = −1.08 V vs. SCE for 1/Au and Epa = −0.78 V, and Epc = −0.84 V vs. SCE for 2/Au. Rectified transmembrane electron transfer through the LB monolayers of 1 and 2 on gold electrodes to [Fe(CN)6]3− in aqueous solutions has been proved by cyclic voltammetry and potential-step chronocoulometry.
  • Koichi Watanabe, Shoichi Sato
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 2 Pages 379-382
    Published: 1994
    Released: July 11, 2006
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    The crystal structure as well as the chemical and physical properties of a new compound, barium tetrahydroxoborate (Ba[B(OH)4]2), are described. The compound is prepared by the chemical reaction of BaCl2 + 2NaBO2 + 4H2O = Ba[B(OH)4]2 + 2NaCl in an aqueous solution. The crystal is monoclinic, space group P21/n with cell constants a = 8.332(2), b = 16.522(3), c = 10.216(3) Å, β = 106.63(2)°, V = 1347.51(6) Å3, Z = 8, Dm = 2.90(1), Dc = 2.85(4) g cm-3. Melting point=ca. 1075 °C; Transition point (γ- to β-form) = ca. 532 °C. Refraction indexes: α = 1.567(6), β = 1.547(6), and γ = 1.517(8).
  • Hiroaki Isago, Yutaka Kagaya
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 2 Pages 383-389
    Published: 1994
    Released: July 11, 2006
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    By the reactions of BiX3 (X = Cl, Br, I, and NO3) with Li2(pc) (pc = phthalocyaninate dianion, C32H16N82−) in dimethyl sulfoxide, N,N-dimethylformamide, acetonitrile, and acetone, [Bi(pc)X] complexes have been produced. These complexes were also produced by heating a mixture of BiX3 and phthalonitrile. Among them, [Bi(pc)Cl] and [Bi(pc)Br] were isolated for the first time as a phthalocyanine complex of group-15 elements and successfully characterized by elemental analyses, solution chemistry, electronic and IR spectroscopy. The latter two complexes were soluble in polar solvents, but were insoluble in nonpolar solvents. In solutions, bismuth(III) in [Bi(pc)X] was labile and was readily expelled from a pc ring by a trace amount of water, acids, and bases, and it was replaced by a divalent transition metal upon the addition of MSO4 (M = cobalt(II), nickel(II), copper(II), and zinc(II)) forming [M(pc)]. The electronic and IR spectra of the [Bi(pc)X]s were characteristic of the usual metallophthalocyanines, except that a hyper metal-to-ligand charge-transfer band appeared in their electronic spectra.
  • Takuyuki Hagiwara, Shoji Motomizu
    1994 Volume 67 Issue 2 Pages 390-397
    Published: 1994
    Released: July 11, 2006
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    For five kinds of triphenylmethane dyes, the rate constants of hydration and dehydration reactions, and equilibrium constants in an aqueous solution were measured by a stopped-flow method. An increase in the number of dialkylamino groups caused a decrease in the rates and the equilibrium constants of the hydration, and the more the electron-donating effect of the dialkylamino groups, the slower the hydration rate became. The more protonated quinonoids were easily converted to the corresponding alcohols. On the basis of the equilibrium constants, Malachite Green was ascertained to be the best reagent of the five dyes for ion association with heteropolyacids in an aqueous medium.
  • Shoji Okuno, Gen-etsu Matsubayashi
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 2 Pages 398-404
    Published: 1994
    Released: July 11, 2006
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    Ferrocene, FcH [Fc = (C5H5)Fe(C5H4)], (ferrocenylalkyl)trimethylammonium iodides, [Fc(CH2)nNMe3]+I (n = 1 or 2), and 1,2-diferrocenylethane, FcCH2CH2Fc, have been intercalated into the V0.21Nb0.79OPO4 interlayer space. The V(V) ion is reduced by the iodide ion and/or the Fc centers, the Nb(V) ion being not reduced. The long-axis direction of the guest molecules is arranged approximately parallel to the swelling V0.21Nb0.79OPO4 sheet. Some Fc centers of FcCH2CH2Fc and FcCH2CH2NMe3+ are not oxidized in spite of their proximity to the metal ion site of the V0.21Nb0.79OPO4 lattice because most of the V sites are isolated from other V sites owing to the low V contents. Ferrocenylalkylamines, FcCH2NMe2 and FcCH2CH2NH2, have been intercalated into the VxNb1−xOPO4 (x = 0, 0.06, 0.11, and 0.21) interlayer spaces, accompanied with the protonated amino groups and the Nb(V) and reduced V(IV) sites. ESR signals of the V0.06Nb0.94OPO4 intercalation compounds exhibit hyperfine structures due to the V(IV) nucleus (I = 7/2). With the increase of the V content in the host lattice, ESR signals are further broadened owing to the dipole–dipole and/or exchange interactions among the V(IV) sites.
  • Toshiaki Hattori, Teruhiko Kawanishi, Masanao Kato
    1994 Volume 67 Issue 2 Pages 405-409
    Published: 1994
    Released: July 11, 2006
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    A plasticized poly(vinyl chloride) membrane electrode was applicable to colloidal titration without selective substances. The change of potential in the end-point, however, was too small to measure accurately. We prepared a new type of electrode with toluidine blue as an indicator. It was found that the electrode was quite useful to the colloidal titration. At the end-point a large change of potential was observed, and a small amount of polyelectrolyte anion could be titrated directly. Potassium poly(vinyl sulfates) was titrated with errors not more than 0.7% of r.s.d. in the amount of several micro chemical equivalents. This method was used to measure some poly(isoplene sulfonates) used as a dispersant polymer and its results agreed with that of acid-base titration.
  • Tomoharu Ama, Toshiaki Yonemura, Hiroshi Kawaguchi, Takaji Yasui
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 2 Pages 410-415
    Published: 1994
    Released: July 11, 2006
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    Four geometrical isomers of [Co(gly)(en)Co(edda)(μ-OH)2]+ were prepared by treating a solution containing [Co(edda)(OH2)2]+ and [Co(gly)(en)(OH2)2] 2+ under basic condition and optically resolved by the chromatographic method. The geometrical structures and absolute configurations of the optically active isomers were assigned on the basis of the NMR, UV, and CD spectral data; the assignments were confirmed based on the spectral data of the mononuclear species which were obtained by the acid hydrolysis of each isomer. Two of the four geometrical isomers are constructed with the α-[Co(edda)(μ-OH)2] and mer(O)-[Co(gly)(en)(μ-OH)2] moieties, and the other two with the β-[Co(edda)(μ-OH)2] and fac(O)-[Co(gly)(en)(μ-OH)2] moieties, the dinuclear structures being stabilized by the two N–H···O hydrogen bonds between the amino H on one metal ion and the carboxyl O on the other metal ion in the dinuclear complex ion.
  • Takumi Konno, Hideki Umehara, Ken-ichi Okanoto, Jinsai Hidaka
    1994 Volume 67 Issue 2 Pages 416-420
    Published: 1994
    Released: July 11, 2006
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    Tetraamine cobalt(III) complexes with monodentate thiolate ligands, [Co(RS)2(amine)4]+, were newly prepared, where R is CH3 or C2H5 and (amine)4 is bis(ethylenediamine) ((en)2), triethylenetetramine (trien), or tris(2-aminoethylamine) (tren). The (en)2 and trien thiolato complexes selectively formed the cis and cis–α isomers, respectively. The oxidation reactions of [Co(RS)2{(en)2 or (trien)}]+ with use of excess H2O2 gave the corresponding S-bonded sulfinato complexes [Co(RSO2-S)2{(en)2 or (trien)}]+ with retention of the initial geometries, while [Co(CH3SO2-S)2(tren)]+ was not formed by the same oxidation reaction of [Co(CH3S)2(tren)]+. The cis-(en)2 and cis–α-trien complexes were optically resolved by the fractional crystallization or column chromatography. The obtained isomers were characterized on the basis of the absorption, CD, and 13C NMR spectra. The thiolato complexes exhibited absorption spectral changes with time in aqueous solutions, which are ascribed to the replacement of the thiolate ligands by H2O.
  • Keiichi Tsukahara, Satoko Asami, Mihoko Okada, Takeshi Sakurai
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 2 Pages 421-431
    Published: 1994
    Released: July 11, 2006
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    Photoinduced electron transfer (ET) between zinc myoglobin (ZnPPMb) and a variety of quenchers, such as hexacyanoferrate(III) ([Fe(CN)6]3−) and hexaammineruthenium(III) ([Ru(NH3)6]3+) ions, cationic viologens, copper(II) protein (stellacyanin), and metmyoglobins, has been studied in aqueous degassed solutions. The excited triplet state of ZnPPMb (*ZnPPMb) was quenched by [Fe(CN)6]3− in a self-associated complex. Both quenching rate constant and formation constant of the self-associated complex decrease with increasing ionic strengths. The thermal backward ET reaction for this system was not observed; it is most likely that the backward ET step is much faster than the quenching reaction. All of the cationic quenchers examined in this work did not form a self-associated complex with *ZnPPMb, and the intermolecular quenching occurred. The thermal backward ET reaction was observed for these cationic quenchers. Not only photoinduced ET but also thermal backward ET reactions were insensitive to the driving force of the reactions, suggesting that the reactions are controlled by conformational changes in ZnPPMb. The quenching rate constants increase with increasing ionic strength for the cationic quenchers. The effects of poly-L-lysine hydrochloride, sodium poly-L-glutamate, and sodium cyclo-hexaphosphate were also examined. The active site of the *ZnPPMb toward both anionic and cationic quenchers is assumed to be the positively charged site near the heme pocket.
  • Tatsuya Sekine, Thi Kim Dung Nguyen, Junji Noro
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 2 Pages 432-437
    Published: 1994
    Released: July 11, 2006
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    The solvent extractions of manganese(II), iron(II), cobalt(II), nickel(II), copper(II), zinc(II), and cadmium(II) (M2+) in 0.1 mol dm−3 sodium nitrate solutions with benzoyltrifluoroacetone and 2-thenoyltrifluoroacetone (HA) into chloroform were studied in the absence and presence of tetrabutylammonium ions (tba+). The addition of tba+ enhanced the extraction, except that of copper(II). This enhancement could be explained in terms of the extraction of the ternary complex, MA3tba+, in addition to the neutral complex, MA2. The data were treated on the basis of the formation equilibrium of the ternary complex from the neutral complex, MA2, with the extracted ion-pairs of the reagents, Atba+, in the organic phase. It was concluded that the association constants of MnA2, FeA2, CoA2, NiA2, and CdA2 with the ion-pair, Atba+, are not very much different from each other. However, that of ZnA2 is lower than those of the five divalent metal complexes. This trend is similar to that found among the adduct metal complexes of β-diketonates with trioctylphosphine oxide (TOPO) in synergistic extraction systems.
  • Masaru Nakatani, Takashi Nakata, Katsushige Kouge, Hideo Okai
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 2 Pages 438-444
    Published: 1994
    Released: July 11, 2006
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    In order to elucidate the relationship between the chemical structure and bitter taste of the C-terminal portion of β-casein, some analogues, in which the phenylalanine residue was substituted by D-phenylalanine, lysine, glycine, glutamic acid or L-pyrenylalanine, were synthesized. Sensory analyses and CD spectra showed that the location of a hydrophobic amino acid with the L-configuration between the two proline residues should be important for this series of peptides to produce a strong bitterness.
  • Norikazu Miyoshi, Seiji Takeuchi, Yoshiaki Ohgo
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 2 Pages 445-451
    Published: 1994
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    Ketenes react with various allylic halides mediated by 2 equiv samarium(II) diiodide (SmI2) to the ketenes to afford allylated ketones in good yields. In the reaction with γ-substituted allylic halides, the regioselectivity is influenced by the olefinic geometry of allylic halides. By using γ-substituted (E)-allylic halides, the allylation proceeds on the less hindered site (α-position) of allylic groups predominantly and the tendency was enhanced by the addition of HMPA.
  • Koji Chiba, Hideyuki Tagaya, Masa Karasu, Masahiko Ishizuka, Toshiyuki ...
    1994 Volume 67 Issue 2 Pages 452-454
    Published: 1994
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    Active methylene compounds were effectively carboxylated with carbon dioxide in the presence of anilide (acetanilide or formanilide) and potassium carbonate at 20—40 °C for 0.5—10 h. In the carboxylation of fluorene, a high yield (48%) was obtained at 20 °C for 4 h. The yield of carboxylic acid using 2,6-dimethylacetanilide was 8.9%, and smaller than 26.6% when using acetanilide at 20 °C for 2 h, indicating the interference of a methyl group for the carboxylation.
  • Shuji Okada, Hiro Matsuda, Masaaki Otsuka, Naoto Kikuchi, Kikuko Hayam ...
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 2 Pages 455-461
    Published: 1994
    Released: July 11, 2006
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    ω-(1,3-Butadiynyl) substituted 1-alkanol and alkanoic acid were synthesized and their polymerization behavior in crystals and in Langmuir–Blodgett (LB) films were investigated. Polymerization, using UV or γ-ray irradiation or thermal treatment, resulted in red- or golden-colored polymers. Since the absorption edge in the visible spectra of these polymers appeared at shorter wavelengths than those of the well known blue-colored polydiacetylenes, π-conjugation is considered to be deteriorated to some extent. IR, X-ray diffraction, and solid-state 13C NMR measurements showed that the polymerization does not proceed in a single-crystal-to-single-crystal transition manner via regular 1,4-addition but with deterioration of the crystalline lattice.
  • Takeshi Hasegawa, Yoshihide Kimura, Yoshiyuki Kuwatani, Hiroyuki Higuc ...
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 2 Pages 462-472
    Published: 1994
    Released: July 11, 2006
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    Cationic rearrangement of 1,4-bis(diarylhydroxymethyl)pentacyclo[4.2.0.02,5.03,8.04,7]octanes (1) in formic acid gave new cage compounds, 8,8-diaryl-2-diarylmethylene-exo-5-(formyloxy)tetracyclo[4.3.0.03,9.04,7]nonan-7-ols (3) and new cage-degradation products, 5,5-diaryl-4-[4-(diarylmethylene)-2-cyclobutenyl]-2-cyclopenten-1-ones (4) along with Wagner–Meerwein rearrangement products, pentacyclo[5.3.0.02,5.03,9.04,8]decanes (5; C2-bishomocubanes) and pentacyclo[5.3.0.02,6.03,9.04,8]decanes (6; D2h-bishomocubanes). 9,9-Diaryl-4-(diarylhydroxymethyl)pentacyclo[4.3.0.02,5.03,8.04,7]nonan-1-ols (2) gave 4, 5, and 6 without the formation of 3. A Wagner–Meerwein 1,2-bond shift of 1 gave key intermediates 2 which were converted into 3 via homoallylic rearrangement, into 4 via pinacol–pinacolone-like rearrangement, or into 5 and 6 via Wagner–Meerwein rearrangement.
  • Koichi Fukase, Takuya Yoshimura, Shozo Kotani, Shoichi Kusumoto
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 2 Pages 473-482
    Published: 1994
    Released: July 11, 2006
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    The proposed fundamental structure of Enterococcus hirae lipoteichoic acid (LTA) was synthesized in order to elucidate the chemical structure responsible for the cytokine-inducing activity described for the natural LTA fraction of this bacteria. Synthesis was accomplished by coupling of the glycolipid part with the poly(glycerol phosphate) (PGP) part by using a phosphoramidite method. The glycolipid part was constructed by coupling of the phosphatidic acid moiety with a kojibiosyl diacylglycerol which had been prepared by stepwise glycosidation with glycosyl fluorides. α-Selective glucosidations were effected by virtue of the 2,2,2-trichloroethoxycarbonyl (Troc) group introduced at the 6-hydroxyl function. p-Nitrobenzyl (NPM) and p-pivaloylaminobenzyl (PAB) groups were successfully applied to temporary protection of hydroxyl functions.
  • Shuji Okada, Hiro Matsuda, Masaaki Otsuka, Hachiro Nakanishi, Masao Ka ...
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 2 Pages 483-489
    Published: 1994
    Released: July 11, 2006
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    The amphiphilic diacetylenes with directly-bound aromatic substituents, i. e. 27-aryl-24,26-heptacosadiyn-1-ols and -diynoic acids, were synthesized and the solid-state polymerization of these compounds upon γ-ray and UV irradiation was investigated. More than half of the compounds synthesized are polymerizable because the packing effect of the methylene chains makes the diacetylene moieties align into polymerizable stack. It is found that the bulkiness of hydrophilic and hydrophobic ends was an impotant factor for the polymerizability of this series of compounds.
  • Masao Hisatome, Jun Watanabe, Rin-ichi Yamashita, Shuichi Yoshida, Koj ...
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 2 Pages 490-494
    Published: 1994
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    The bridge contraction of α-oxo[4]ferrocenophane via a Wolff rearrangement was examined; β-formylation with ethyl formate, diazotization with tosyl azide and then irradiation with a mercury lamp in ethanol gave α-ethoxycarbonyl[3]ferrocenophane. A sequence of the reactions was applied to di- and tribridged α-oxo[4]ferrocenophanes to afford the corresponding [3]ferrocenophanes. The same reaction of α-oxo[4][33](1,2,3,4)ferroceneophane yielded α-oxo[3][33](1,2,3,4)ferrocenophane (20), but no α-ethoxycarbonyl[3][33](1,2,3,4)ferrocenophane, which was an usual product in the Wolff rearrangement in ethanol. The production of an unexpected compound 20 is possibly brought about by the addition of dioxygen to an ketene intermediate in the rearrangement, followed by removal of carbon dioxide. Reduction of 20 has led to the first synthesis of 1, tetrabridged ferrocenophane with trimethylene chains in a C2v symmetric mode.
  • Yoshitomo Nagata, Toshihiro Aso, Takatoshi Kinoshita, Yoshiharu Tsujit ...
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 2 Pages 495-499
    Published: 1994
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    Poly(γ-methyl L-glutamate-co-L-glutamic acid) containing a β-cyclodextrin at the terminal (MG/GA-CyD) was prepared and the relationship investigated between the conformation of the polypeptide and inclusion capability of the β-cyclodextrin by circular dichroism and fluorescence spectroscopy in aqueous solution containing 8-anilino-1-naphthalenesulfonate (ANS) as a guest molecule. The terminal β-cyclodextrin of MG/GA-CyD could not include ANS at higher pH, where the polypeptide almost formed a random coil. This was attributed to the terminal β-cyclodextrin being concealed in the random coil of the polypeptide. At low pH, however, random coil-to-α-helix transition of the polypeptide exposed the terminal β-cyclodextrin to the aqueous phase resulting in the ANS-inclusion capability. These results imply that control of the polypeptide conformation leads to conformational switched guest binding of the terminal cyclodextrin.
  • Nobujiro Shimizu, Sin-ichiro Watanabe, Fumie Hayakawa, Sigefumi Yasuha ...
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 2 Pages 500-504
    Published: 1994
    Released: July 11, 2006
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    The kinetic β-silicon effects of various silyl groups including Me3Si, Me3SiMe2Si, (C6H5)Me2Si, (i-PrO)Me2Si, and (CH3OCH2)Me2Si were measured in kc solvolysis of two different benzylic systems of the types, ArCH(OCOCF3)CH2R (3: Ar = phenyl or 3,5-dichlorophenyl, R = silyl group) and C6H5CH(Cl)SiMe2R (4: R = silyl group). The relative β-silyl accelerations were 1.0 : 5.57 : 0.309 for R = Me3Si; Me3SiMe2Si, and (C6H5)Me2Si, respectively, for the system 3, and 1.0 : 7.65 : 0.502 : 0.289 for R = Me3Si, Me3SiMe2Si, (i-PrO)Me2Si, and (CH3OCH2)Me2Si, respectively, for the system 4. The variation of the β-silicon effect with γ-substituents was interpreted as reflecting changes in hyperconjugating abilities of β-C–Si and β-Si–Si σ-bonds mainly due to the inductive effect of the γ-substituent groups.
  • Masahide Yasuda, Goro Kuwamura, Takumi Nakazono, Kensuke Shima, Yoshih ...
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 2 Pages 505-510
    Published: 1994
    Released: July 11, 2006
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    Comparative X-ray crystallographic analyses of tetra-t-butyl 1,2,4,5-benzenetetracarboxylate (1) and highly congested hexa-t-butyl benzenehexacarboxylate (2) have shown that t-butoxycarbonyl groups in 2 are much more twisted with respect to the benzene ring and bond-elongated in the peripheral positions than those in 1 or hexamethyl benzenehexacarboxylate. Such deformations and the staggered carbonyl orientation, all arising from the steric hindrance, may be responsible for the unusual dual-fluorescence behavior of the sterically congested hexaester 2.
  • Yasuhiko Kawamura, Hisanori Takatsuki, Fumihito Torii, Tokunaru Horie
    1994 Volume 67 Issue 2 Pages 511-515
    Published: 1994
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    Demethylation of 2′-methoxyacetophenones with anhydrous aluminum chloride in acetonitrile was studied to survey its scope and limitations. The mechanism which the reaction proceeds via sterically constrained intermediates was proposed from the substituent effects. Additionally, dealkylation of 2′-benzyloxy-, 2′-ethoxy-, and 2′-isopropoxyacetophenones with two demethylating reagents, hydrochloric acid in acetic acid and anhydrous aluminum bromide in acetonitrile, was studied. It was found that the reactivity was greatly affected by the steric factor between the alkoxyl group and reagent. This behavior may have wide application in selection of protecting groups in organic synthesis.
  • Keita Hamasaki, Akihiko Ueno, Fujio Toda, Iwao Suzuki, Tetsuo Osa
    1994 Volume 67 Issue 2 Pages 516-523
    Published: 1994
    Released: July 11, 2006
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    Modified α, β, and γ-cyclodextrins that bear one p-(dimethylamino)benzoyl (DMAB) moiety (DMAB-αCyD, DMAB-βCyD, and DMAB-γCyD, respectively) were synthesized as fluometric molecular recognition indicators. These three modified cyclodextrins show dual fluorescence arising from normal planar and twisted intramolecular charge transfer (TICT) excited states. Among them, the TICT emission was particularly great in the case of DMAB-βCyD. The TICT fluorescence intensity increased for DMAB-αCyD and DMAB-γCyD, and decreased for DMAB-βCyD when the hosts form inclusion complexes with guest molecules, and the variation of the TICT emission intensity was used as a sensitivity parameter. DMAB-αCyD was effective to detect chain compounds while DMAB-γCyD showed high sensitivities to bulky compounds including several steroids. Various guest compounds were detected by DMAB-βCyD, The orders of the sensitivities of the hosts were parallel with those of the binding constants except for the case of DMAB-γCyD. The results demonstrate that these fluorescent CyDs are useful as fluorescent indicators of molecular recognition.
  • Yasushi Kawai, Munekazu Tsujimoto, Shin-ichi Kondo, Kousuke Takanobe, ...
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 2 Pages 524-528
    Published: 1994
    Released: July 11, 2006
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    Various β-keto esters have been reduced by one of β-keto ester reductases isolated from bakers’ yeast. The corresponding β-hydroxy esters have been obtained in excellent enantiomeric and diastereomeric excesses, respectively. It has also been elucidated that the reductase recognizes the stereochemistry not only at the β-carbon but also at the α-carbon affording one of the four possible diastereoisomers of α-substituted β-hydroxy esters predominantly. The stereoselectivity is excellent and chemical yields are moderate to good.
  • Keiichi Mitsuta, Midori Hiramatsu, Hiroaki Ohya-Nishiguchi, Hitoshi Ka ...
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 2 Pages 529-538
    Published: 1994
    Released: July 11, 2006
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    The superoxide dismutase (SOD) activity of Cu,Zn-, Mn-, and Fe-SODs, and the SOD-like activity of ferricytochrome c, nitro blue tetrazolium (NBT), epinephrine, pyrogallol, L-ascorbic acid, and hydroxylamine, were investigated by the method of kinetic competition against superoxide radicals (O2−•) using ESR spectroscopy with a nitrone spin-trap 5,5-dimethyl-1-pyrroline N-oxide (DMPO). These activities depended on the pH and/or kind of the O2−• generating system used. A comparison of the results obtained for two O2−• generating systems of KO2 and hypoxanthine–xanthine oxidase showed that the effective pH in the former system was 1 or more higher than that in the latter. A new competition kinetic theory which includes a parameter of the stoichiometric ratio has been developed. Consequently, the profile of the non-stoichiometric competition reaction between DMPO and scavengers for O2−• was theoretically clarified.
  • Seishi Izumi, Naoki Toshima
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 2 Pages 539-545
    Published: 1994
    Released: July 11, 2006
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    Polypyrrole was prepared by the oxidation of pyrrole with molecular oxygen in the presence of bis(acetylacetonato)(oxo)vanadium(IV) (VO(acac)2) and aluminum chloride (AlCl3) as a catalyst. The polymerization of pyrrole at 20 °C at a mole ratio of VO(acac)2/AlCl3 = 1/1 in acetonitrile under 1 atm of oxygen gave polypyrrole, 10−2 S cm−1 in electrocondutivity in 260% yield on the basis of the catalyst charged. The addition of pyridine to the system improved the electroconductivity of the polypyrrole produced. The reaction mechanism is discussed based on the UV-vis spectra of the reaction mixtures, the ESR spectra of the catalytic system, and the oxygen consumption during polymerization.
  • Masahiro Fujiwara, Hisanori Ando, Mutsuo Tanaka, Yoshie Souma
    1994 Volume 67 Issue 2 Pages 546-550
    Published: 1994
    Released: July 11, 2006
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    The hydrogenation of carbon dioxide for methanol synthesis was studied over Cu–Zn–Cr oxide catalysts, which were prepared by using CrO3 as a source of chromium. From the results of improving this type of catalysts, a catalyst prepared by the addition of copper–zinc carbonate to an aqueous solution of CrO3 was confirmed to be the most effective in this study. The detailed reaction behaviors, such as the dependence on the pressure, temperature and space velocity, were studied using this catalyst.
  • Mamoru Ai, Etsuhiro Muneyama, Atsuhiro Kunishige, Kyoji Ohdan
    1994 Volume 67 Issue 2 Pages 551-556
    Published: 1994
    Released: July 11, 2006
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    The catalytic performances of iron phosphate were compared with those obtained from the phosphates of vanadium and molybdenum in the partial oxidation of various compounds, such as 1-butene, crotonaldehyde, methacrylaldehyde, propinaldehyde, butyraldehyde, isobutyraldehyde, propionic acid, butyric acid, and isobutyric acid. Iron phosphate showed excellent performance for only the oxidative dehydrogenation of isobutyraldehyde and isobutyric acid to form methacrylaldehyde and methacrylic acid, respectively.
  • Chikafumi Yokoyama, Makoto Misono
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 2 Pages 557-562
    Published: 1994
    Released: July 11, 2006
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    Catalytic reduction of dilute nitrogen monoxide by propene in the presence of excess oxygen was studied over various metal ion-exchanged zeolites. The presence of propene and oxygen was essential for the reaction. Ce–zeolites, particularly Ce–ZMS-5, showed a very high catalytic activity for the reduction of nitrogen monoxide. The high activity of Ce–ZSM-5 was attributed to its high selectivity (high efficiency of the use of propene for the reduction). The addition of alkaline earth metals to Ce–ZSM-5 enhanced the activity considerably and the Ce–ZSM-5 containing alkaline earth metals showed good performance even at a very high space velocity (GHSV = 105 h−1).
  • Yoshihiro Kubota, Kazuhiko Takeuchi, Taka-aki Hanaoka, Yoshihiro Sugi
    1994 Volume 67 Issue 2 Pages 563-571
    Published: 1994
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    For the purpose of synthesizing heat-resistant polyesters, the one-step synthesis of a rigid biphenyl-containing polyester from dihalobiphenyl and diol by palladium-catalyzed carbonylation-polycondensation was examined. The reaction parameters, such as the base, solvent, palladium–phosphine catalyst and CO pressure in the reaction of 2,7-dibromo-9,10-dihydrophenanthrene and 4,4′-(1-methylethylidene)bisphenol (bisphenol A), were found to significantly affect the molecular weight of the resulting polyester. Under the optimum conditions, poly[oxy-1,4-phenylene(1-methylethylidene)-1,4-phenyleneoxycarbonyl(9,10-dihydro-2,7-phenanthrenediyl)carbonyl] (1) were obtained in 95% yield with high molecular weight (polystyrene equivalent Mw = 102600). By choosing the phosphine ligands and controlling the pressure of carbon monoxide, polymer 1 was obtained with a Mw of 10000—100000. The procedure was applied to various dihalobiphenyls and diols. Polycondensation with 1,10-decanediol gave poly[oxydecamethyleneoxycarbonyl(9,10-dihydro-2,7-phenanthrenediyl)carbonyl] (15) with a much lower molecular weight (Mw = 4900) than polyester 1. On the basis of a thermal analysis, a 5% weight-loss temperature (T5) and a 10% weight-loss temperature (T10) of 1 in air was 394 and 414 °C, respectively, whereas melting temperature (Tm), T5, and T10 of 15 were 148, 369, and 383 °C, respectively.
  • Yoshimi Sueishi, Yukie Sugiyama, Shunzo Yamamoto, Norio Nishimura
    1994 Volume 67 Issue 2 Pages 572-574
    Published: 1994
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    The equilibrium between lactone and zwitterion forms of Rhodamine B was studied in primary alcohols and at high pressures. The effects of solvent polarity and pressure on the equilibrium constant were examined by using a Kirkwood-type equation.
  • Yasuhisa Maeda, Ai Katsuta
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 2 Pages 575-577
    Published: 1994
    Released: July 11, 2006
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    The anodic oxidation of polyaniline in aqueous solutions containing SO42− and PO43− ions caused an exothermic change at lower potential and an endothermic change at higher potential, but only the exothermic change was observed in the anodic process of polyaniline in a solution containing ClO4 ions.
  • Isao Sanemasa, Hiroko Takahashi, Kazunari Ishibashi, Toshio Deguchi
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 2 Pages 578-581
    Published: 1994
    Released: July 11, 2006
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    Cyclodextrins (β- and γ-CyDs) were precipitated in an aqueous medium at 25 °C in the presence of a naphthalene (N)–biphenyl (B) mixed guest. The N/B molar ratio in the precipitates was found to be governed by SN·KN (SB·KB)−1, where S refers to the solubility of the guest in water and K to the 1 : 1 association constant of the CyD–guest.
  • Kazuhiro Kobayashi, Tohru Mannami, Masataka Kawakita, Junsuke Tokimats ...
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 2 Pages 582-585
    Published: 1994
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    A new method for the preparation of 3-isochromanone derivatives is reported. The method consists of the ethoxycarbonylation of o-acylbenzyllithiums with ethyl chloroformate and the subsequent NaBH4 reduction of the resulting o-acylphenylacetic acid derivatives.
  • Yukihiro Okada, Yuji Sugitani, Yoshinori Kasai, Jun Nishimura
    1994 Volume 67 Issue 2 Pages 586-588
    Published: 1994
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    Calix[4]arene analog (2) having 2-[2-(2-methoxyethoxy)ethoxy]ethyl groups was prepared in 92% yield. Compound 2 showed the extraction of alkali metal ions as an ionophore and the catalytic activity for some SN2 reactions.
  • Kiyoshi Tanaka, Sigeaki Nagatani, Masaki Ohsuga, Keiryo Mitsuhashi
    1994 Volume 67 Issue 2 Pages 589-591
    Published: 1994
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    Trifluoromethylated azomethine ylide 1, generated in situ by the conrotatory ring opening of cis-2-benzoyl-1-methyl-3-trifluoromethylaziridine, cycloadded with both electron-deficient and -rich monosubstituted olefins to give exclusively the corresponding 3-substituted pyrrolidines. This high regioselectivity is discussed in connection with the interaction between 1-LUMO and olefin-HOMO.
  • Gouki Fukata, Yukihiro Kubota, Shuntaro Mataka, Thies Thiemann, Masash ...
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 2 Pages 592-594
    Published: 1994
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    4-Bromo- and 4-Chloro-3-t-butylphenol, two potent fungistatics, were prepared in an efficient 3-step synthesis from commercially available materials. Crucial to the synthesis is the use of halo-substituents as positional protective groups.
  • Tsutomu Inokuchi, Hiroyuki Kawafuchi, Kenji Aoki, Akihito Yoshida, Sig ...
    1994 Volume 67 Issue 2 Pages 595-598
    Published: 1994
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    An improved procedure for the electrochemical radical cyclization of 2-bromoethyl 2-alkynyl ethers has been developed by the combined use of chloro(pyridine)cobaloxime(III) and a zinc plate as a sacrificial anode in an undivided cell. The reaction is feasible with 5 mol% of the cobalt catalyst and applicable to a variety of bromo acetals under neutral conditions.
  • Hiyoshizo Kotsuki, Tadashi Yamaguchi, Keiji Ohno, Yoshikatsu Ichikawa, ...
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 2 Pages 599-602
    Published: 1994
    Released: July 11, 2006
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    The reactions of α-trimethylsiloxy-, α-methoxy-, and α-ethoxystyrene with dimethyl acetylenedicarboxylate (DMAD) and dimethyl fumarate (DMFM) have been investigated. With DMAD the 1 : 1 Diels–Alder and the 1 : 2 Diels–Alder ene adducts were obtained, while the reaction with DMFM gave novel open-chain adducts through alkyl group migration and incorporation of the solvent.
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