Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
Volume 77 , Issue 7
Showing 1-23 articles out of 23 articles from the selected issue
Award Accounts
The Chemical Society of Japan Award for Creative Work for 2002
The Chemical Society of Japan Award for Young Chemists for 2002
Headline Articles
Organic and Biological
  • Takashi Sagawa, Rika Tanaka, Fumiyuki Ozawa
    2004 Volume 77 Issue 7 Pages 1287-1295
    Published: 2004
    Released: July 09, 2004
    JOURNALS RESTRICTED ACCESS
    The reaction of Me3GeSnMe3 with a platinum(0) complex, in situ generated from [Pt(cod)2] (cod = 1,5-cyclooctadiene) and 2 molar quantity of PMe2Ph in Et2O, formed a cis–trans mixture of [Pt(GeMe3)(SnMe3)(PMe2Ph)2] (1). Recrystallization of crude 1 from CH2Cl2–pentane gave pure cis-1, while the isolated cis isomer was again converted to an equilibrium mixture (cis:trans = 8:2) in solution. The cis–trans mixture of 1 underwent competitive insertion of phenylacetylene into Pt–Sn and Pt–Ge bonds to give cis-[Pt(GeMe3){C(Ph)=CH(SnMe3)}(PMe2Ph)2] (2a) and cis-[Pt{C(Ph)=CH(GeMe3)}(SnMe3)(PMe2Ph)2] (3a), respectively, in a ratio of 80:20, while 2a was thermodynamically less stable, and converted to 3a in solution. The insertion mechanism was examined by kinetic investigations.
Articles
Theoretical and Physical
  • Ali Maghari, Amir Hossein Jalili
    2004 Volume 77 Issue 7 Pages 1297-1303
    Published: 2004
    Released: July 09, 2004
    JOURNALS RESTRICTED ACCESS
    Effective intermolecular potential-energy functions for O2–O2, N2–N2, and O2–N2 are obtained directly from the extended law of corresponding states for viscosity and experimental second virial coefficient data. The results are then used to obtain a best Morse–Spline–van der Waals (MSV) potential model. The present potential functions provide the best overall agreement for the available low-density gas-phase thermophysical data, i.e., second virial coefficient and transport properties. The effective intermolecular potential energies from the inversion of thermophysical data reproduce the viscosity, diffusion coefficient, and other transport coefficients within the experimental accuracy.
  • Takashi Yumura, Kazunari Yoshizawa
    2004 Volume 77 Issue 7 Pages 1305-1311
    Published: 2004
    Released: July 09, 2004
    JOURNALS RESTRICTED ACCESS
    The vibrational structures for two possible peroxo intermediates of soluble methane monooxygenase (sMMO), in which O2 binds into the diiron(II) active site with end-on and side-on bridging modes, are analyzed from quantum chemical calculations at the B3LYP DFT level of theory. Dioxygen bridging modes should be controlled by carboxylate coordinations around the diiron active site. Two bridging carboxylato ligands are contained in the end-on peroxo complex, whereas one bridging carboxylato ligand is contained in the side-on peroxo complex. DFT calculations demonstrate that the end-on bridging mode into the diiron active site is energetically more stable than the side-on bridging mode. The end-on peroxo complex has a vibrational mode of O–O stretching at 909 cm−1, the isomer shift of which upon 18O2 substitution is 57 cm−1. The side-on peroxo complex exhibits a lower O–O stretching mode at 841 cm−1, and the isotope shift is 45 cm−1. The frequency of the O–O stretching mode and the 18O2 isotope shift are dependent on the dioxygen bridging modes in the active site of sMMO. The O–O stretching frequency in the end-on complex falls within the range measured in peroxo intermediates of other non-heme diiron enzymes and cis-μ-1,2 peroxo-bridged diiron(III) synthetic complexes. From the viewpoint of energetics and the vibrational frequencies, it is predicted that O2 should coordinate into the diiron active site of sMMO in an end-on cis-μ-1,2 fashion rather than a side-on fashion.
  • Atula S. D. Sandanayaka, Yasuyuki Araki, Chuping Luo, Mamoru Fujitsuka ...
    2004 Volume 77 Issue 7 Pages 1313-1322
    Published: 2004
    Released: July 09, 2004
    JOURNALS RESTRICTED ACCESS
    Dynamic quenching processes of the excited states of C60 with amine donors have been studied by changing donor strength, donor concentration, and solvent polarity using steady-state and transient absorption and fluorescence spectroscopic techniques. Fluorescence quenching of C60 by amines was observed, which suggests a dynamic quenching process via the excited singlet state of C60 (1C60*) in polar and nonpolar solvents. In polar solvents, electron transfer via the excited triplet state of C60 (3C60*) producing radical ions (C60•− and amine•+) was observed by the nanosecond laser flash photolysis (ca. 6 ns laser pulse). When the donor concentrations are below 10–20 mmol dm−3, the concentrations of the radical ions increased with the donor concentrations. With further increase of the concentrations of the donors up to 100 mmol dm−3, on the other hand, the yields of the radical ions generated via 3C60* decreased. These findings indicate that dynamic quenching of 1C60* by amines increases with donor concentrations, resulting in a decrease of the intersystem crossing path to 3C60*; thus, the yields of the radical ions generated via 3C60* decreased even in the highly polar solvent. This implies that the radical ions generated by the dynamic quenching of 1C60* may be quite short-lived, even in polar solvents, compared with the radical ions via 3C60*.
  • Kouichi Nakagawa
    2004 Volume 77 Issue 7 Pages 1323-1329
    Published: 2004
    Released: July 09, 2004
    JOURNALS RESTRICTED ACCESS
    The partitioning, rotational correlation times (τR), and electron spin–lattice relaxation times (T1e) of various small spin probes in dispersions of a triglyceride membrane were investigated using CW-ESR (continuous wave-electron spin resonance) and SR (saturation recovery) spectroscopies. The partitioning of small spin probes, DTBN and TEMPO, in the aqueous and vesicle phases was determined by an ESR linewidth simulation. The results suggest that DTBN and TEMPO have a similar partitioning in the vesicle phase throughout the temperatures studied. The simulation results were quite different from those of conventional intensity analysis. In addition, the rotational correlation times of the vesicle phase for both probes varied from 1.2 × 10−10 to 4.9 × 10−10 s. The activation energy (Ea) calculated from the τR values in the phase was ∼29 [kJ/mol] for the probes. The thermal behavior based on the Ea value is that in between the 12-doxylstearic acid (12-DSA) and 16-DSA moieties of the membrane. The longer τR and shorter T1e (∼0.33 μs) values of DTBN in the vesicle phase were obtained, and could be attributed to the probe environment in the membrane. Thus, the present experimental evidence has provided a qualitative understanding of the probe dynamics as well as the membrane properties.
Analytical and Inorganic
  • Kosei Ueno, Fumihiko Kitagawa, Noboru Kitamura
    2004 Volume 77 Issue 7 Pages 1331-1338
    Published: 2004
    Released: July 09, 2004
    JOURNALS RESTRICTED ACCESS
    Polymer microchannel chips (100 μm width × 20 μm depth) integrated with electrodes were fabricated and applied to a one-step electrochemical cyanation reaction of pyrene (PyH). An acetonitrile solution of PyH containing tetrabutylammonium perchlorate and an aqueous NaCN solution were brought into the chip by pressure-driven flow, PyH was then oxidized at the working band electrode in the channel (1.5 V vs Ag). Under the optimum conditions, 1-cyanopyrene (PyCN) was produced very efficiently in the microchannel: 61% yield. It was also confirmed that, although 1,3-dicyanopyrene (Py(CN)2) was produced by bulk electrolysis (14% yield), its yield decreased to 4% in the microchip, with the PyCN/Py(CN)2 yield ratio being 2.9 or 15.3 for the bulk or chip experiments, respectively. In the case of an oil/water interfacial reaction system, a propylene carbonate solution of PyH and an aqueous NaCN solution were introduced to the channel, where an electrochemical cyanation reaction of PyH analogous to that mentioned above was conducted. The interfacial reaction in the microchip was successful and the yield of PyCN as the sole product was shown to be controlled by both the flow rate and the electrode position in the chip. In-situ space-resolved absorption spectroscopy of the electrochemical intermediate in the channel chip was also conducted to allow discussion of the reaction mechanisms.
  • Hideo Hashizume
    2004 Volume 77 Issue 7 Pages 1339-1342
    Published: 2004
    Released: July 09, 2004
    JOURNALS RESTRICTED ACCESS
    The stability of a mesoporous material, FSM-16, against water vapor and water was investigated using an X-ray diffractometer with a relative humidity and temperature controlling unit. Under high relative humidity, the peaks for FSM-16 became smaller than the initial one from 60% of the relative humidity (RH) during an increase of the relative humidity from 10 to 95%, and the peak height was a minimum from 80 to 95% RH. However, the peaks for FSM-16 increased and returned back to the initial ones at 20% RH, while the relative humidity decreased. In soaked FSM-16 in water at 95% RH, the peaks for FSM-16 diminished owing to water. However, the peaks for FSM-16 appeared again, while water evaporated, and the peak heights were almost the same as the initial ones at 20% RH. However, the peak heights were about 25% lower than the initial ones after soaking FSM-16 in water for a long term. It might be supposed that the particles of FSM-16 on a sample holder were rearranged due to the pouring water, or that some of the mesopores for FSM-16 collapsed due to water.
  • Kohta Matsumoto, Noboru Sekine, Keisuke Arimura, Masaaki Ohba, Hiroshi ...
    2004 Volume 77 Issue 7 Pages 1343-1351
    Published: 2004
    Released: July 09, 2004
    JOURNALS RESTRICTED ACCESS
    The dinucleating macrocyclic ligand (L2;2)2−, prepared by the [1:1] cyclic condensation of N,N′-dimethyl-N,N′-ethylenedi(5-bromo-3-formyl-2-hydroxybenzylamine) and ethylenediamine, has dissimilar N(amine)2O2 and N(imine)2O2 metal-binding sites sharing two phenolic oxygen atoms. It has afforded μ-acetato-di-μ-phenolato-metal(II)cobalt(II) complexes (metal(II) = FeII, CoII, NiII, CuII, ZnII). X-ray crystallographic studies indicate that the MII is bound to the N(amine)2O2 site and has a square-pyramidal geometry with an acetate oxygen at the axial site. The CoII bound to the N(imine)2O2 site has a square-pyramidal geometry with an acetate oxygen at the apex or a distorted octahedral geometry with further coordination of a methanol molecule. The CoII in the N(imine)2O2 site is of low-spin and has one unpaired electron in its dz2 orbital. Magnetic studies indicate an antiferromagnetic interaction in the FeCo and CoCo complexes whereas a ferromagnetic interaction in the NiCo and CuCo complexes. The magnetic properties of the complexes are discussed in terms of the electronic structure of the MII ion and the dinuclear MCo core structure.
  • Kazuhiko Tsukagoshi, Hirofumi Indou, Kaori Sawanoi, Takako Oguni, Riic ...
    2004 Volume 77 Issue 7 Pages 1353-1357
    Published: 2004
    Released: July 09, 2004
    JOURNALS RESTRICTED ACCESS
    A fused-silica capillary modified with anti-human serum albumin was prepared using the glutaraldehyde method after activating the inner wall with a silane coupling reagent. The antibody selectively interacted via an immune reaction with the human serum albumin, which acted as an antigen. The analytical performance of the modified capillary was examined by capillary affinity chromatography using either absorption or chemiluminescence detection. The capillary affinity chromatography required only minimal reagents and samples due to the extremely small diameter of the capillary. For chemiluminescence detection, a peroxyoxalate reagent was used and human serum albumin was labeled with fluorescamine for competitive immunoassay. After optimization of the analytical conditions, chemiluminescence detection showed a higher sensitivity than absorption detection. Furthermore, a modified capillary was also used in capillary electrophoresis with the absorption detector to allow affinity capillary electrophoresis.
  • Shigeaki Oyama, Yoshihiro Doi, Yukio Hinatsu, Yoshinobu Ishii
    2004 Volume 77 Issue 7 Pages 1359-1366
    Published: 2004
    Released: July 09, 2004
    JOURNALS RESTRICTED ACCESS
    The synthesis, crystal structure, and magnetic properties of quaternary oxides Ba3Ln2MO9 (Ln = Y, Sm–Gd, Dy–Lu for M = Mo; Ln = Y, Sm–Lu for M = W) are reported. Their powder X-ray diffraction measurements and Rietveld analysis showed that they have a “disordered” perovskite structure, i.e., BaLn2/3M1/3O3 except for Ba3Tb2WO9, and that their structures are monoclinic with space group I2/c (Ln = Y, Sm–Gd, Dy–Yb for M = Mo; Ln = Y, Sm–Lu for M = W) or cubic with space group Pmm (Ln = Lu for M = Mo). Powder neutron diffraction measurements showed that Ba3Tb2WO9 has an ordered perovskite structure and is monoclinic with space group P21/n. Magnetic susceptibility measurements showed that all the Ba3Ln2MO9 compounds are paramagnetic down to 1.8 K. The Tb ions of Ba3Tb2WO9 are in the mixed valence state (+3, +4). Through 151Eu Mössbauer measurements on Ba3Eu2MoO9 and Ba3Eu2WO9, it was found that the Eu ion is in the trivalent state, and that the symmetry of the Eu site is distorted from the octahedral symmetry.
Organic and Biological
Applied and Materials
feedback
Top