Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
Volume 67 , Issue 3
Showing 1-49 articles out of 49 articles from the selected issue
  • Ahmed Abdel-Azim Ahmed Boraei, Elham Mohamed Abd Alla, Mohamed Rafat M ...
    1994 Volume 67 Issue 3 Pages 603-606
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    1 : 1 Charge-transfer molecular complexes of some quinolines with iodine as a σ-electron acceptor were synthesized and charcterized. The spectral characteristics and stability of the formed charge-transfer comlexes were determined and are discussed in terms of the basicity and molecular structure of the donor as well as the solvent polarity. It is deduced that such factors as the n-donor strength, steric effect, and solvent polarity play operative roles in determining the stability of these CT complexes. The formed complexes are ascertained to be of a strong nσ kind.
  • Aloke Kumar Chakraborty, Ashis Bhattacharjee, Biswanath Mallik
    1994 Volume 67 Issue 3 Pages 607-611
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    The dark conduction properties of ferrocenedicarboxylic acid have been studied as a function of voltage at different sample-temperatures by using sandwich type of cell configuration. The analysis of the results was based on the space charge limited conduction (SCLC) theory. The trap distribution in this material has been found to be exponential type as was observed in case of ferrocene and ferrocenecarboxylic acid. The dark activation energy (ohmic) of these ferrocene derivatives increases with the gradual substitution of –COOH group in the ferrocene ring system. In contrast to the nonextrinsic nature of ferrocenecarboxylic acid, ferrocenedicarboxylic acid has been observed to be extrinsic, similar to ferrocene. The photoconductivity in these materials was studied as a function of temperature and the intensity of exciting light source. The distribution of traps in these materials has been determined from the intensity dependence of photocurrent and these results have been compared with the results of dark conductivity measurements.
  • Tamotsu Inabe, Isabelle Luneau, Tadaoki Mitani, Yusei Maruyama, Sadamu ...
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 3 Pages 612-621
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    Two kinds of N-(2-hydroxy-1-naphthylmethylene)aniline-type compounds, N-(2-hydroxy-1-naphthylmethylene)-1-pyrenamine (NPY) and N,N′-bis(2-hydroxy-1-naphthylmethylene)-p-phenylenediamine (DNP), have heen prepared as members of the N-salicylideneaniline family and subjected to structural studies in the crystalline state. In NPY, the hydrogen in the intramolecular N···H–O hydrogen bond has been found to locate not only at the oxygen site, but also at the nitrogen site, even at 120 K. A similar hydrogen-bond structure has also been found for DNP. This is mainly due to the π-electron delocalization effect. The relative stabilization of the proton transferred form (NH-form) compared with ordianry N-salicylideneanilines has been clearly indicated by solid-state NMR measurements.
  • Tamotsu Inabe, Naomi Hoshino-Miyajima, Isabelle Luneau, Tadaoki Mitani ...
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 3 Pages 622-632
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    TCNQ and F4TCNQ complexes of N-(2-hydroxy-1-naphthylmethylene)aniline-type compounds, N-(2-hydroxy-1-naphthylmethylene)-1-pyrenamine (NPY) and N,N′-bis(2-hydroxy-1-naphthylmethylene)-p-phenylenediamine (DNP) have been prepared and subjected to structural and optical studies in the crystalline state. An X-ray crystallographic study indicates that the donors and acceptors are mixed along a one-dimensional column in all complexes. The intramolecular O–H···N hydrogen bond structure is sensitively changed upon complex formation; the hydrogen atom is located at the nitrogen site in TCNQ complexes and shifts to the center of the hydrogen bond in F4TCNQ complexes. The hydrogen-bond structure is found to vary with some correlation to the strength of the charge-transfer interaction.
  • Jun Yamauchi
    1994 Volume 67 Issue 3 Pages 633-636
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    The magnetic susceptibility of the 1,3-bis(2,2′-biphenylene)-2-phenylallyl (BDPA) complex with acetone exhibited a broad maximum at around 10 K, characterized by a linear Heisenberg-type magnetic interaction; a discontinuity in dχ/dT at ca. 2.8 K was observed, suggesting an antiferromagnetic spin-ordering. The magnetic behavior in the paramagnetic region is discussed in terms of the Weiss temperature, exchange interaction parameters, and a divergent character in the ESR linewidth and g-value. The spin-ordered state was ascertained by antiferromagnetic resonance, in which one of the resonance branches showed a rapid temperature dependence, indicating a transition temperature of 3.1 K. Compared with the magnetic data of the BDPA–benzene complex, it was concluded that the magnetic characteristics were greatly influenced by solvent complexation and that the magnetic parameters in both the paramagnetic and antiferromagnetic regions were enhanced by changing the incorporated solvent from benzene to acetone.
  • Hideta Ishihara, Shi-qi Dou, Alarich Weiss
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 3 Pages 637-640
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    The crystal structure of the title compound was determined (T = 300 K): , Z = 2, a = 1085.8, b = 1064.3, c = 929.0 pm, α = 97.83, β = 108.86, γ = 99.24°, R(F) = 0.047, Rw(F) = 0.041. Characteristic for the structure is the dimer structure of SbBr52− ion. The atomic coordination around the Sb atom is a distorted octahedron. The 81Br NQR spectrum was studied in the temperature range 77 ≤ T/K ≤ 350. The 81Br NQR frequencies are spread out over a wide range at 77 K: 37 ≤ ν(81Br)/MHz ≤ 111. The temperature dependence of the NQR frequencies and of their spread is given as is an assignment of 81Br NQR lines to the positions of Br atoms in the anion.
  • Akihiro Noguchi, Shin-ichi Kondo, Masayuki Kuzuya
    1994 Volume 67 Issue 3 Pages 641-647
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    The bond cleavage of poly(acrylic acid) (PAA) and poly(methacrylic acid) (PMAA) in their excited states was investigated by means of molecular orbital calculations (AM1 and INDO/S-CI methods) using model molecules. The calculated reaction potentials for the bond cleavages in the excited states showed that the most dissociative bonds are the α-C–H bond for PAA and the C–C bond associated with the decarboxylation for PMAA. β-C–C bond cleavage following the above-mentioned side-bond cleavages seems to be feasible in the higher excited states. The formation of free radicals in the plasma- and γ-irradiations of PAA, PMAA, and their esters could be well explained as reactions in the excited states.
  • Masataka Kuroda, Kazuto Yamazaki, Tetsu Kobayashi, Nobutaka Fujii, Too ...
    1994 Volume 67 Issue 3 Pages 648-652
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    Solvent effects were introduced into a Monte-Carlo simulation of peptide conformations by the use of a new potential function for evaluating the nonbonding interactions between solute and solvent molecules. The Monte-Carlo program, which included the electrostatic and nonbonding interactions of the solvent, was tested for a conformation analysis of the zwitterionic tetragastrin in DMSO. The theoretical coupling constants were in good agreement with the NMR data. The conformation of the zwitterion was a folded compact form at the lowest energy, which was different from those obtained from a simulation in vacuo and that without nonbonding solvent effects.
  • Tadanori Hashimoto, Toshinobu Yoko, Sumio Sakka
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 3 Pages 653-660
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    Rutile and anatase thin films have been prepared by the sol–gel method using Ti(OC3H7i)4. Third-order nonlinear optical properties of both TiO2 thin films have been investigated by the third-harmonic generation (THG) method and the effect of the polymorph of TiO2 on the third-order nonlinear optical susceptibility, χ(3), has been examined. The measured χ(3) values of rutile and anatase thin films were 1.4 × 10−12 and 9.7 × 10−13 esu, respectively. The χ(3) values corrected for the porosity of the film were 4.0 × 10−12 (rutile) and 2.4 × 10−12 esu (anatase), which are about 100 times as high as that of SiO2 glass used as standard sample (2.8 × 10−14 esu). The measured and corrected χ(3) values were discussed in comparision with those calculated on the basis of several models.
  • Takehiko Mori, Hiroo Inokuchi, Yohji Misaki, Tokio Yamabe, Hatsumi Mor ...
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 3 Pages 661-667
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    Methylthio substituted bis-fused tetrathiafulvalene, TTM-TTP (2,5-bis[4,5-bis(methylthio)-1,3-dithiol-2-ylidene]-1,3,4,6-tetrathiaphentalene) makes three phases of iodine complexes: (TTM-TTP)I3, α-(TTM-TTP)2I3, and β-(TTM-TTP)2I3. The 1 : 1 complex exhibits high conductivity, 700 S cm−1 at room temperature, and is metallic down to about TMI = 160 K. This complex has uniform columns of the donor molecules. In the semiconducting α-(TTM-TTP)2I3, one quarter of the donors is incorporated in the anion sheet, and the sides of the other trimeric donors are blocked by the anion sheets. β-(TTM-TTP)2I3 shows metallic conductivity down to TMI = 20 K.
  • Katsunori Kohata, Hisao Higashio, Yuichi Yamaguchi, Mamoru Koketsu, Ts ...
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 3 Pages 668-679
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    Six new styles of water-soluble glycosylated porphyrins (5, 10, 15, 20-tetrakis[2-, 3- or 4-(β-D-glucopyranosyl)phenyl]porphine) were synthesized and studied concerning their structures by 1H and 13C NMR. Tetrakis (o-substituted phenyl)porphine, consisting of four atropisomers (αβαβ, ααββ, αααβ, and αααα), was clearly assigned based on the 13C NMR peak-splitting pattern. It was especially noteworthy that water-soluble picket-fence porphyrin (αααα) was obtained. Furthermore, their characterization as a chromogenic reagent for metal ions was investigated. The introduction of highly water-soluble glucose successfully improved the aggregration and adsorption characteristics of the anionic or cationic porphyrins so far prepared without any marked change in the other important analytical properties.
  • Narumi Sakagami, Takaji Yasui, Hiroshi Kawaguchi, Tomoharu Ama, Sumio ...
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 3 Pages 680-686
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    The crystal structures of the isomers (one α and two β) of [Co(eddp)(en)]+ were determined by X-ray diffraction methods. Crystal data for -Δ(S,S)-α-[Co(eddp)(en)]Br·5H2O (1) are monoclinic with space group P21: a = 10.558(2), b = 8.523(2), c = 11.868(2) Å, β = 112.11(1)°, and Z = 2. Crystal data for (+)536CD-Δ(R,R*)-β(e-1)-[Co(eddp)(en)]Br·H2O (2-a) are orthorhombic with P212121: a = 11.809(2), b = 16.144(2), c = 8.340(2) Å, and Z = 4. rac-β(e-1)-[Co(eddp)(en)]Cl·H2O (2-b) is characterized in the triclinic space group : a = 9.084(2), b = 10.800(2), c = 8.337(1) Å, α = 99.37(1), β = 93.14(2), γ = 105.72(2)°, and Z = 2. rac-β(e-2)-[Co(eddp)(en)](PF6)·3H2O (3) crystallizes in the monoclinic (C2/c): a = 23.216(2), b = 11.980(2), c = 19.768(2) Å, β = 133.314(2)°, and Z = 8. Two β isomers (β(e-1) and β(e-2)) were found to be conformational diastereomers arising from a difference in the chirality around one of two asymmetric nitrogen atoms in the coordinated eddp ligand.
  • Toshihiro Moriga, Osamu Usaka, Tomomi Imamura, Ichiro Nakabayashi, Ich ...
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 3 Pages 687-693
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    Two kinds of oxygen-deficient phases around LaNiO2.5 were obtained by a low-temperature H2 reduction of perovskite-type LaNiO3. An antiferromagnetic LaNiO2.5 with TN 140 K seems to be stoichiometric and a small amount of excess oxygen leads to a new ferromagnetic phases. A structural refinement has revealed that the former (space group C 2/c) comprised one-dimensionally linked NiO6 octahedra along the c-axis and NiO4 square-planars connecting the octahedra chains. A cooperative Jahn–Teller distortion was observed in both coordination polyhedra, which suggested that LaNiO2.5 has octahedral Ni3+ ions with the low-spin state and square-planar Ni+ ions. Its magnetic property and XPS spectrum support this model. The new ferromagnetism with Tc 230 K could be understood due to a slight canting in the antiferromagnetic interaction between the octahedra and the square-planes.
  • Isao Kawafune, Gen-etsu Matsubayashi
    1994 Volume 67 Issue 3 Pages 694-698
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    The A-type trisubsituted, β-isomer of tetrabutylammonium 3-molybdo-9-tungstophosphate(3-), A-β-[NBun4]3[PMoVI3W9O40], reacted with triphenylphosphine in acetonitrile to afford triphenylphosphine oxide and an oxygen-deficient two-electron reduced species, A-β-[NBun4]3[PMoVIMoV2W9O39]. The reduced species was isolated and characterized by IR, 31P NMR, and X-ray photoelectron spectroscopies. The corner-sharing bridging oxygen atom in a Mo(VI)–O–Mo(VI) skeleton was eliminated upon the reduction, affording two Mo(V) ions in the polyanion moiety retaining the Keggin-type structure.
  • Takehiro Abe
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 3 Pages 699-704
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    A simple theoretical expression for the redox potential of a redox couple (X/X−• or X/X) has been presented by using a modified Born equation and has been successfully applied to the organic and inorganic redox couples the reliable standard redox potentials of which are directly measured electrochemically, and to polarographic half-wave redox potentials of organic compounds. The expression has also been applied to inorganic redox couples the provisional standard redox potentials of which are estimated indirectly by using thermodynamic cycles, to examine the validity of the provisional potentials. At least, the provisional redox potentials, with which the potentials calculated approximately agree, seem to be reliable.
  • Toru Arai, Kimio Kashitani, Hiroshi Kondo, Shigeyoshi Sakaki
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 3 Pages 705-709
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    Ni(tmtaa) efficiently catalyzes the reductive dehalogenation of alkyl halide, yielding alkane with either NaBH4 or NaBH(OMe)3 under mild condition. This system is considered to be a model of factor F430, the active center of the methyl coenzyme M reductase. Deuterium incorporation into the alkane suggests that the reaction involves not only an electron transfer, but also the nucleophilic substitution of a halide. The ESR spectrum of Ni(tmtaa)/NaBH4 shows the formation of the NiI species, which is probably a catalytic-active species.
  • Toshiki Taya, Yukinobu Mukouyama, Kunio Doi, Makoto Otomo
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 3 Pages 710-719
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    The equilibria of nickel(II) ion with thirteen nitrogen-heterocyclic hydrazones (neutral form: HL) with and without blocking group(s) have been investigated spectrophotometrically in 28% aqueous dioxane solution at 25 °C and an ionic strength of 0.2 (KCl). For a series of 2-pyridinecarbaldehyde 5-substituted-2-pyridylhydrazones, the following linear free energy relationships (LFER) were derived between the overall formation constants, β1, β1′, and β2, of Ni(HL)2+, NiL+, and Ni(HL)22+ complexes, respectively, and the dissociation constants, Ka1 and Ka2, of H3L2+ and H2L+, respectively: log β1 = 0.95 (pKa1 + pKa2)/2 + 4.60, 1/2 log β2 = 0.95 × (pKa1 + pKa2)/2 + 4.82, and log β1′ = 1.40 (pKa1 + pKa2)/2 + 9.73.
    The steric effects of the 6-methyl group in pyridine and the quinolyl ring in place of pyridyl group on the complex formation were evaluated on the basis of LFER. The complex stabilization effect of the pyridyl group substituted for formyl hydrogen was also evaluated for Ni(HL)22+, Ni(HL)2+, and NiL+ complexes. These results together with LFER were discussed in conjunction with the thermodynamic parameters for the formation of Ni(HL)2+ complex and the ligand field parameters, Dq, for Ni(HL)2+ and Ni(HL)22+ complexes.
  • Yu-ichiro Kumamoto, Jian Wang, Kitao Fujiwara
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 3 Pages 720-727
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    Laser photolysis was used to investigate the production and quenching of hydrated electrons formed after absorption of 355 nm light by dissolved organic matter (DOM) in natural waters. Correlation between the hydrated electrons generated and dissolved organic carbon in seawaters was found. The DOM in land waters ejected more hydrated electrons than seawater DOM did. Land waters contained much natural fluorescent organic matter, so the DOM in the land waters was rich in photochemically sensitive chromophores. Quenching of the hydrated electrons by the inorganic ions, nitrite, nitrate, Cd2+, Ni2+, Co2+, and [Co(NH3)6]3+ were investigated by a first-order function and the Stern–Volmer model. With the former, the quenching rate constants were 10−9 to 10−10 dm3 mol−1 s−1, which was close to reported values. No regional differences were found among the seawater samples. This result suggested similar quenching mechanisms for hydrated electrons generated in the different seawaters. With the Stern–Volmer model, primary quenching was estimated. Quenching studies of land waters suggested that DOM had an aggregate nature in such waters.
  • Naoki Haga, Ichiro Ishikawa, Hiroaki Takayanagi, Haruo Ogura
    1994 Volume 67 Issue 3 Pages 728-737
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    Direct and ketone (acetone or acetophenone)-sensitized photocycloaddition of 2,3-dimethyl-2-butene to 2′-deoxyuridine (1a), thymidine (1b), 5-fluoro-2′-deoxyuridine (1c), and their 3′,5′-di-O-acetyl derivatives 1d1f by near-UV irradiation have been studied. The triplet excited state of the nucleosides was found to be the major intermeidate by the triplet quenching technique. From the respective reactants, a pair of diastereomeric products having a cyclobutane ring were isolated. The absolute configuration of the bridgehead carbon atoms was identified by X-ray crystallographic analyses with two of them as (1R, 6R)-isomer 3a and (1S, 6S)-isomer 2b and by 1H NMR. The conformations of the glycosyl bond, the pyrimidine ring, and the sugar portion in solution were identified by 1H NMR and compared with the ones in the crystalline state.
  • Galal Eldin Hamza Elgemeie, Samia E. El-Ezbawy, Hosny A. Ali, Abdel-Ka ...
    1994 Volume 67 Issue 3 Pages 738-741
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    A novel synthesis of 7-methylthiopyrazolo[1,5-a]pyrimidines via reaction of [bis(methylthio)methylene]malononitrile and ethyl 2-cyano-3,3-bis(methylthio)acrylate with 5-aminopyrazoles is reported and the synthetic potential of the method is demonstrated.
  • Yasukazu Ohkatsu, Taiki Watanabe, Taiji Goto, Mitsuaki Wakita
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 3 Pages 742-747
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    As cytochrome P-450 model compounds with structures similar to heme proteins, we designed and synthesized novel porphyrin iron (III) chloride complexes, 11 and 12, which have three peptide chains (3PCs) and four peptide chains (4PCs), and evaluated their catalytic activities. The asymmetric porphyrin complexes are derived from etioporphyrin and peptide chains equivalent to proteins were provided by ring-opening polymerization of N-carboxy L-amino acid anhydride (L-Phe-NCA, γ-BLG-NCA, and Nε-benzyloxycarbonyl-L-Lys-NCA) initiated by amino groups on meso positions. The new asymmetric porphyrin complex, 11 or 12, was used for asymmetric epoxidations of styrene as is done by cytochrome P-450. The iron complex achieved the induction of asymmetry, although it has no special conformation, and gave S-styrene oxide in excess (ca. 60%ee). It was found, furthermore, that asymmetric induction was affected by the kind of amino acid residue, the number of peptide chains, and length of peptide chains.
  • Tamae Matsuishi, Toyoshi Shimada, Kensaku Morihara
    1994 Volume 67 Issue 3 Pages 748-756
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    Imprinting using chiral 5-phenyhydantoins ((5R)- and (5S)-5-pheny-2,4-imidazolinedione) as templates could mark chiral molecular footprint-like cavities on a silica (alumina) gel surface. These cavities displayed evident enantioselective catalyses in reactions of (R)- and (S)-N-carboxyphenylglycine anhydrides, and (R)- and (S)-5-phenylhydantoins with 2,4-dinitrophenolate, respectively. A proposed mechanism and temperature effects on catalysis suggested that the enantioselectivities depended on the binding step of the catalysis.
  • Kazunori Matsuura, Yasuo Kimura, Hisakazu Takahashi, Toshio Morita, Ic ...
    1994 Volume 67 Issue 3 Pages 757-765
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    Friedel–Crafts acylation, bromination, deuteration, and nitration of acetylpentamethylbenzene (APMB), 1-acetyl-2,3,4,6-tetramethylbenzene (ATMB), and 1-benzoyl-2,3,4,6-tetramethylbenzene (BTMB) and the resulting product distributions were investigated. Friedel–Crafts acylation, bromination, and deuteration of APMB and Friedel–Crafts acylation of ATMB gave deacetylation-substitution products. On the other hand, bromination and deuteration of ATMB (or BTMB) and Friedel–Crafts acylation of BTMB gave 5-substituted products. In both cases, the positional reactivities were in accordance with the relative σ-complex stability. Conversely, except for Friedel–Crafts-type nitration, the positional reactivities in the nitration of these substrates were strikingly different from those of the above three reactions. Thus, side-chain functionalization at the 6-methyl group occurred in nitration with fuming nitric acid, depending on the solvents in use. The MNDO calculations and the reaction of APMB with single-electron transfer reagents such as tetranitromethane- or cerium(IV) ammonium nitrate suggest that the product distribution in nitration can be explained in terms of a single-electron transfer mechanism.
  • Kazuo Takimiya, Akiko Ohnishi, Yoshio Aso, Tetsuo Otsubo, Fumio Ogura, ...
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 3 Pages 766-772
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    Various radical cation salts of 2,3-dimethyl-tetrathioanthracene (DMTTA) and -tetraselenoanthracene (DMTSA) with NO3, BF4, ClO4, PF6, AsF6, and Br counter anions were prepared by an electrocrystallization technique. It has been found that these salts have either 1 : 1 or 2 : 1 stoichiometry depending on the volumes of the anions, but all are electrically conductive regardless of the stoichiometries. In particular, the NO3 and BF4 salts of DMTSA, in spite of 1 : 1 stoichiometry, recorded unusually high room temperature conductivities of 440 and 450 S cm−1, respectively, and had metallic behaviors down to around 200 K. In addition, the other salts were semiconductors with very low activation energies. X-Ray crystallographic analyses showed that the crystal structures of all the salts consist of one-dimensional stacking columns of the donor molecules, but the two metallic salts have more favorable uniform stacking columns in which there are not only effective π electronic interactions but also strong heteroatomic interactions. Furthermore, solid electronic spectra indicated that these 1 : 1 radical cation salts have the advantage of marked reduction of on-site Coulombic repulsion in the donor molecules, which serves to suppress a Mott transition.
  • Yoshitomo Nagata, Takatoshi Kinoshita, Akira Takizawa, Yoshiharu Tsuji ...
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 3 Pages 773-777
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    Interaction between a Cu2+-α-helical polypeptide containing side-chain pyridyl groups, poly(Nω-2-pyridylmethyl-L-glutamine) (P2PG), and poly(4-vinylpyridine) (P4VP) as a macromolecular guest was investigated by absorption and circular dichroism spectroscopies in 2,2,2-trifluoroethanol solutions. P4VP was added to the Cu2+-one pyridyl side chain complex system prepared in advance. One or two P4VP nitrogens could bind to the remaining coordination sites of the Cu2+ ion in the host system, yielding ternary Cu2+ complexes. The circular dichroism spectra of Cu2+-P2PG with P4VP indicated that P4VP might bind to the α-helix of P2PG in such a manner as to form a left-handed superhelix around the α-helical core resulting from the formation of ternary Cu2+ complexes. The structure of the interpolymer complex system was also investigated by a monolayer method. The surface pressure–area isotherm of a Cu2+-P2PG-P4VP monolayer and its hysteresis supported the formation of the supramolecular structure suggested by the spectroscopic methods.
  • Masahiko Iyoda, Tsutomu Nakagawa, Hajime Ebe, Masaji Oda, Masazumi Nak ...
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 3 Pages 778-791
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    A bisdehydro[14]annuleno[c]furan and a tetrakisdehydro[14]annuleno[14]annulene have been synthesized; their properties and effects of annelation on annulene rings are discussed on the basis of 1H NMR and electronic spectra. Attempts to synthesize the related [14]annuleno[16]annuleno[14]annulene are also described.
  • Eisaku Nomura, Hisaji Taniguchi, Yoshio Otsuji
    1994 Volume 67 Issue 3 Pages 792-799
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    The dichlorocarbene generation reaction from CHCl3 and solid KOH in CH2Cl2 was catalyzed by the p-t-butylcalix[6]arene derivative 1 which bears six 3,6,9-trioxadecyl substituents on the phenolic oxygens. Dichlorocarbene generated by this method reacted efficiently with alkenes and amides to give dichlorocyclopropane derivatives and nitriles, respectively, in high yields. The reaction with alkadiene having isolated double bonds gave mixtures of the mono- and bis-dichlorocarbene adducts, but the monoadduct formation always predominated. The catalytic action of the calixarene and the reactivity features of dichlorocarbene generated by the above procedure are discussed on the basis of kinetic measurements. They are also compared with those of the 18-crown-6-catalyzed reactions.
  • Ze-jian Guo, Hideto Miyoshi, Toshio Fujita
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 3 Pages 800-806
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    The acid dissociation constants of a number of multisubstituted diarylamines measured in an α-dodecyl-ω-hydroxyocta(oxyethylene) micellar system (log ) were compared with those measured in 50% (v/v) EtOH–water mixture (log ). The electronic effects of substituents on log values were similar to, whereas the steric effect of substituents was larger than, those examined previously on the log values. The acid dissociation constant of each compound was generally larger in the less polar (ε: ca. 28) micellar system than that in 50% EtOH–water mixture (ε: ca. 52). To understand this phenomenon, solvent effects on the dissociation constant of compound 37 as a model were examined. We found that compound 37 forms a hydrogen-bonded or proton-transfer complex with DMSO in CHCl3. The anionic form of compound 37 was favored in partition at a higher DMSO content in a DMSO–water mixture compared to the neutral form. These results suggest that contributions of such as hydrogen bonding and dispersion force are of primary importance regarding the effect on the acid dissociation of the series of compounds in the micellar system.
  • Kenji Okada, Shinichi Takekuma
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 3 Pages 807-815
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    The crystal and molecular structures of title compound 1 have been determined by single-crystal X-ray diffraction analysis. Crystals are monoclinic, space group P21, with a = 14.058(2), b = 11.911(1), c = 11.753(2) Å, β = 111.73(1)°, Z = 4. The structure identification was refined by full-matrix least-squares calculations to a final R of 0.054 for 2899 independently observed reflections. The crystallographic asymmetric unit contains two independent molecules with similar geometries and planar conformations. In each molecule, cyclohexane ring A has a typical chair form. Cyclohexene rings B and C, containing of two conjugated double bonds, have half-chair conformations. The relative stereochemistry for both molecules is trans fusion for the A/B ring junction [14.9(2) and 14.6(3)°], anti between C9 hydrogen and C10 methyl (steroid numbering), and coplanar for the B/C ring junction [5.7(2) and 3.5(2)°]. The dihedral angles between the mean plane of ring A and the carboxyl group are nearly right angles [74.6(2) and 86.2(2)°]. Thermal motion analysis in rigid-body approximation and potential energy calculations suggest that the isopropyl groups are more freely in these regions. The isopropyl C atoms had large thermal motions. The hydrogen bonds of carboxyl groups are rigid between two independent molecules.
  • Tomomi Kinoshita, Koichi Shibayama, Masaki Takemoto, Ken’ichi Ta ...
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 3 Pages 816-823
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    Optically active 1-(p-tolyl)ethyl p-nitrobenzoate (ROPNB) has been subjected to solvolysis in phenol where the solvolysis was previously found to proceed via a single stable ion-pair intermediate (Int-1) with high selectivity for nucleophiles, i.e., to exhibit the kinetic features expressed by the “B” pattern for the kpkt profile. On the basis of the absolute configurations and the maximum rotations for the substrate and all of the products which have been chemically established, the stereochemical courses have been disclosed to be partial retention for ROPh formation (“retentive phenolysis”) and partial inversion for o- and p-RC6H4OH formation with predominant racemization in the solvolysis. These stereochemical outcomes indicate that the key intermediate (Int-1) which provides all of the products should have the structure of a carbocation ion pair shielded at the rear side by a phenol molecule (the rear-side shielded ion-pair intermediate) similarly to the key intermediates which are known for some other phenolysis systems. Consequently, the rear-side shielded ion-pair intermediate plays a key role regarding product formation in all retentive phenolysis systems.
  • Tsutomu Mitsuhashi, Hiroshi Hirota, Gaku Yamamoto
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 3 Pages 824-830
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    Rates of heterolytic decompositions of t-butyl chloride, bromide, iodide, and 2,4-dinitrophenolate have been measured by an NMR method in eight deuterated or undeuterated polar solvents; methanol-d4, ethanol-d6, dimethyl-d6 sulfoxide, N,N-dimethylformamide-d7, acetonitrile-d3, pyridine, nitrobenzene, and acetone-d6. The observed solvent effect is discussed on the basis of cation and anion solvation. With t-butyl halides, the anion solvation due to hydrogen bonding by protic solvents drastically decreases on increasing the radius of halide ions, and thus the differential solvation transferred from anion-solvating methanol to cation-solvating dimethyl sulfoxide is dramatically reversed on going from the chloride to the iodide (kMe2SO–d6/kmethanol–d4 at 60 °C: t-BuCl, 5 × 10−2; t-BuBr, 6 × 10−1; t-BuI, 7). The 2,4-dinitrophenolate behaves like the iodide. Complicated products are obtained in the decomposition of t-butyl bromide in dimethyl sulfoxide; however, a mechanism involving a bimolecular decomposition process of the bromide is ruled out. During the decomposition of t-butyl iodide in dimethyl sulfoxide, an intermediate salt t-butoxydimethylsulfonium iodide has been detected. The salt decomposes to isobutene, but the process is much slower than the heterolytic decomposition of t-butyl iodide itself at ambient temperature.
  • Tsutomu Mitsuhashi, Gaku Yamamoto, Hiroshi Hirota
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 3 Pages 831-838
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    A number of heterolysis reactions which are insusceptible or less susceptible to hydrogen bonding by protic solvents are exemplified. It is emphasized that reactions of this type are as important as those of the hydrogen bond-susceptible type that are prone to be taken as a common feature of heterolysis reactions. Evidence that a primary factor in determining the type of reaction is the relative importance of cation and anion solvation is given by introducing a two-parameter equation for solvent effects on the rate: ΔG = ΔGDMSOa(χ+ + − 1) in which χ+ and χ are scales for cation and anion solvation for a particular solvent, respectively. These scales have been derived from purely kinetic data for eight solvents; methanol, ethanol, dimethyl sulfoxide (DMSO), N,N-dimethylformamide, acetonitrile, pyridine, nitrobenzene, and acetone. The equation applies satisfactorily to twelve typical heterolysis reactions. The coefficients a and b represent the sensitivity to solvent change and the relative importance of cation and anion solvation, respectively. When b = 1, the rate in DMSO is equal to that in methanol, and thus heterolysis reactions can be classified: b > 1, hydrogen bond-susceptible; b < 1, hydrogen bond-insusceptible.
  • Tadahiro Kato, Toshihumi Hirukawa, Masakuni Yano
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 3 Pages 839-842
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    Our previous research concerning anti-rice blast fungus substances from the rice plants has led to the isolation of various types of oxygenated fatty acids as exemplified by 9,12,13-trihydroxy C-18 fatty acid. The fatty acids play an important role in the defense of the rice plants against this fungus. For evaluation of biological activity, we needed the isomeric trihydroxy fatty acids. This paper describes the synthesis of four stereoisomers of 9,10,13-trihydroxy fatty acid.
  • Shinya Morishita, Ken-ichi Suzuki
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 3 Pages 843-846
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    In the presence of citric acid, the photoelectrochemical deposition of nickel onto TiO2-sol particles was observed due to the quantum size effect. Selective plating of nickel onto irradiated parts of a TiO2-adhered-alumina plate without resists was accomplished in an electroless nickel plating solution containing citric acid.
  • Yoshihiro Suzuki, Yoshiyuki Koseki, Kohshin Takahashi, Syuichi Matsui, ...
    1994 Volume 67 Issue 3 Pages 847-853
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    For an electrocatalytic oxidation of cyclohexene in an air-equilibrated acetonitrile solution containing (5,10,15,20-tetraphenylporphyrinato)manganese(III) as a catalyst, benzoic anhydride as an acylating reagent and 1-methylimidazole as a ligand to Mn porphyrin, the addition of the compounds such as Methylene Blue, Safranine-T, and viologens promotes the production of cyclohexene oxide. The result implies that these compounds act effectively as mediators for the electron transfer from electrode to Mn porphyrin because they have more negative reduction potential than Mn porphyrin. The faradaic efficiency reaches about 100% by the use of benzylviologen under an optimum condition. But, in the presence of methylene blue, the maximum faradaic efficiency gives low values of about 30%. On the other hand, cyclohexene oxide is also produced by the use of zinc powder as a reductant, but the utilization efficiency of zinc gives relatively low values of 30—40% regardless of the kind of the mediator. This result is ascribed to the irreversible reduction of the mediator and the direct reaction of oxomanganese complex, which is an intermediate in this epoxidation reaction, with zinc powder.
  • Animesh Kumar Rakshit, Veena Vangani
    1994 Volume 67 Issue 3 Pages 854-855
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    Critical reverse micelle concentration (crmc) of Span 60 in toluene was determined by iodine solubilization method at 20, 25, 30, and 35 °C. The corresponding thermodynamic quantities of reverse micellization process were computed and are discussed.
  • Kunio Tamaki, Yoko Ohara, Yukiko Akimoto, Kyoko Koshiishi
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 3 Pages 856-858
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    The viscosity B coefficients for aqueous solutions of disodium α,ω-alkanedisulfonates NaO3S(CH2)nSO3Na (n = 2, 4, 6—8, 10, and 12) and disodium α,ω-alkanediyl disulfates NaO3SO(CH2)nOSO3Na (n = 2, 4, 6, 8, and 10) have been determined at 15, 25, and 35 °C. The effect of structural changes in the solvent water upon the dissolution of these amphiphilic electrolytes is discussed.
  • Kenji Yasuoka, Mitsuhiro Matsumoto, Yosuke Kataoka
    1994 Volume 67 Issue 3 Pages 859-862
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    A particle insertion method is applied to investigate the local chemical potential near a liquid free surface of argon and methanol. Although methanol has a significant ordering of molecular orientation, the chemical potential is constant for both cases, which is contrary to the prediction of a transition state theory.
  • Katsuaki Shimazu, Yukari Sato, Ichizo Yagi, Kohei Uosaki
    1994 Volume 67 Issue 3 Pages 863-865
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    Self-assembled monolayers of 11-ferrocenyl-1-undecanethiol on Pt have been characterized with an electrochemical quartz crystal microbalance and X-ray photoelectron spectroscopy. Well-packed monolayers were defect-free, but less compact than on Au. The high affinity of Pt for oxygen made the monolayer relatively unstable compared with monolayers on Au.
  • Mamoru Sato, Yukiteru Katsube, Masaaki Katai, Jun’ichi Katakawa, ...
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 3 Pages 866-868
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    The three-dimensional structure of asebotoxin IV has been determined by X-ray diffraction at room temperature. The crystals are triclinic, space group P1, with a = 9.934(2), b = 8.8746(9), c = 7.0073(9) Å, α = 71.05(1), β = 80.04(1), γ = 70.71(1)°, V = 549.8(2) Å3, Z = 1, Dc = 1.337 g cm−3. The structure was solved by the direct method and refined by the full matrix least-squares method to a final R = 0.038 for 1604 independent reflections with Fo > 3σ (Fo). The molecule is based on a tetracyclic structure consisting of two five-membered, one six-membered and one seven-membered rings with various conformations.
  • Masaaki Kojima, Yasuhiro Shimizu, Kiyohiko Nakajima, Yuzo Yoshikawa
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 3 Pages 869-872
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    The cis(t-N,O)-[Co{OS(O)CH2CH2NH2-O,N}{N(CH2CH2NH2)3}]2+ (t-N = tertiary amine nitrogen) complex was prepared by photolysis of the corresponding S,N-chelate sulfinato complex. The structure of the linkage-isomerized product was determined by the X-ray method. Optical resolution of the O,N-chelate complex was achieved by SP-Sephadex column chromatography, and the racemization of the complex was studied.
  • Fuminori Akiyama
    1994 Volume 67 Issue 3 Pages 873-875
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    Reaction of the reduction products of carbon dioxide (CO2) by benzoin carbanion with triphenylcarbenium ion (1) gave 1-(diphenylmethyl)-4-(triphenylmethyl)benzene (2) which was considered to be electron transfer product from the reduction products of CO2 to 1.
  • Yuji Takikawa, Hiroyuki Watanabe, Ryuji Sasaki, Kazuaki Shimada
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 3 Pages 876-878
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    The reactions of amides and N,N,N′,N′-tetramethylurea with (Me3Si)2Se in the presence of BF3·OEt2 afforded the corresponding slelenoxo compounds in good yields. On the other hand, selenation of ethyl and butyl benzoates in a similar manner gave benzoin and 2,3,5,6-tetraphenyl-1,4-diselenin via selenoesters. The trapping of selenoesters was also achieved by 2,3-dimethyl-1,3-butadiene to afford [4+2] cycloadducts.
  • Yoshihisa Watanabe, Kazuhiro Nishiyama, Kunsan Zhang, Fumio Okuda, Ter ...
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 3 Pages 879-882
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    Co2(CO)8-catalyzed ring-opening carbonylation of oxiranes and oxetane smoothly proceeds with high regioselectivity under 1 atm of carbon monoxide at room temperature to give the corresponding β- and γ-siloxy amides in high yields, respectively. [(R3Si)2NR1R2]+[Co(CO)4] is thought to be an active catalyst species and directs the high regioselectivity of the carbonylation.
  • Yo Miyagi, Machiko Takano
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 3 Pages 883-884
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    A facile reaction between N,N′-bis(ethoxycarbonyl)-p-benzoquinone diimine and electron-donating para-substituted phenols proceeded at room temperature in benzene in the presence of benzoic acid to give adducts which were formed by insertion of the diimine into the O–H bond of the phenols.
  • Takeshi Oriyama, Mikio Kimura, Gen Koga
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 3 Pages 885-887
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    The combined use of dimethoxymethane with catalytic amounts of tin(II) bromide and bromomethyl methyl ether cleaves p-methoxybenzyl ethers to give methoxymethyl ethers in good yields. The chemoselective conversion of p-methoxybenzyl ethers in the presence of the benzyl ether function into methoxymethyl ethers has also occurred successfully.
  • Sadayuki Matsuda
    1994 Volume 67 Issue 3 Pages 888-890
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    The association of the S-100 protein was studied by the HPLC of gel filtration in the presence of 0.5 mM Zn2+. To avoid any association of the proteins, it was necessary for the dissoving buffer to contain urea of 6 M concentration. This conclusion was confirmed by fluorescence measurements of S-100a.a′.
  • Takashi Karatsu, Tatsuo Arai, Hirochika Sakuragi, Katsumi Tokumaru, Ja ...
    1994 Volume 67 Issue 3 Pages 891-894
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    Semiempirical PPP-SCF-SCI calculations support the assignment of the triplet–triplet absorption spectra of 2-anthrylethylenes to the planar trans conformations, which act as a key intermediate in adiabatic cis-to-trans one-way isomerization on the triplet energy surface.
  • Shigeru Murata, Hiroshi Tsuji, Hideo Tomioka
    Type: Accounts
    Subject area: AI
    1994 Volume 67 Issue 3 Pages 895-897
    Published: 1994
    Released: July 12, 2006
    JOURNALS RESTRICTED ACCESS
    Photolysis of 2-amino-2′-azidobiphenyls in diethylamine gave 4,10-dihydroazepino[2,3-b]indoles (7), the structure of which corresponded to the didehydroazepines formally trapped with an internal amino group. However, the yields of 7 were considerably low, which was due to the significant intramolecular interaction of the photolytically generated nitrene with an amino group, to afford benzo[c]cinnoline as a final product.
feedback
Top