Proceedings of the Japan Academy, Series B
Online ISSN : 1349-2896
Print ISSN : 0386-2208
ISSN-L : 0386-2208
Volume 83, Issue 3
Displaying 1-3 of 3 articles from this issue
  • Take-aki MITSUDO, Yasuyuki URA, Teruyuki KONDO
    2007 Volume 83 Issue 3 Pages 65-76
    Published: 2007
    Released on J-STAGE: May 01, 2007
    A novel zerovalent ruthenium complex with a π-acidic ligand, Ru(η6-cyclooctatriene)(η2-dimethyl fumarate)2 (1), was prepared from Ru(η4-cyclooctadiene)(η6-cyclooctatriene) [Ru(cod)(cot)]. Complex 1 or Ru(cod)(cot) catalyzes various new carbon-carbon bond-forming reactions that include the [2 + 2] cycloaddition of alkenes and alkynes via ruthenacycles, the creation of a new hydrocarbon, pentacyclo[,6.03,13.010,14]tetradeca-4,11-diene [PCTD], by dimerization of 2,5-norbornadiene via C-C bond cleavage, and the codimerization of alkynes and/or alkenes. Complex 1 was shown to be an excellent mother complex for various zerovalent ruthenium complexes. Complex 1 reacts with amines, phosphines or water to give new zerovalent ruthenium complexes with the ligands. The resulting aqua complexes have a water ligand with an oxygen atom that is a chiral center, i.e., ruthenium complexes with a `chiral water' ligand were prepared and fully characterized.

    (Communicated by Hitosi NOZAKI, M.J.A.)
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  • Yousuke SEYAMA, Yasunobu UCHIJIMA
    2007 Volume 83 Issue 3 Pages 77-96
    Published: 2007
    Released on J-STAGE: May 01, 2007
    Sexual diversity of ADG in Harderian gland of golden hamster was demonstrated on TLC. Female ADG contained iso- and anteiso-branched acyl and alkyl components, but male ADG contained only straight chain ones, which suggested the hormonal control of the expression of acyl-CoA dehydrogenases in the catabolism of BCAA. Acyl-CoA dehydrogenases were not expressed in the absence of testosterone, and then isovaleryl-CoA, 2-methylbutyryl-CoA, and isobutyryl-CoA accumulated, and acted as primers for the synthesis of iso- and anteiso-branched fatty acids. The incorporation of [U-14C] leucine into lipids was monitored by TLC. The cholesterol fraction was labeled in males but not in female, which means that cholesterol was not produced from BCAA in female gland due to the lack of expression of acyl-CoA dehydrogenases. We monitored the behavior of male hamsters toward female gland lipids, and found slightly greater attractiveness in female ones than that in male ones although the difference was not significant. Considering the lifestyle of golden hamster in nature, we propose a hypothesis that the lipids from the Harderian gland of golden hamster serve as a pheromone to declare their territory and to seek the mate with good congeniality.

    (Communicated by Tamio YAMAKAWA, M.J.A.)
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  • Kenji OHTA, Kei HIROSE, Suzue ONODA, Katsuya SHIMIZU
    2007 Volume 83 Issue 3 Pages 97-100
    Published: 2007
    Released on J-STAGE: May 01, 2007
    We measured the electrical conductivity of Mg0.81Fe0.19O magnesiowüstite, one of the important minerals comprising Earth's lower mantle, at high pressures up to 135 GPa and 300 K in a diamond-anvil cell (DAC). The results demonstrate that the electrical conductivity increases with increasing pressure to about 60 GPa and exhibits anomalous behavior at higher pressures; it conversely decreases to around 80 GPa and again increases very mildly with pressure. These observed changes may be explained by the high-spin to low-spin transition of iron in magnesiowüstite that was previously reported to occur in a similar pressure range. A very small pressure effect on the electrical conductivity above 80 GPa suggests that a dominant conduction mechanism changes by this electronic spin transition. The electrical conductivity below 2000-km depth in the mantle may be much smaller than previously thought, since the spin transition takes place also in (Mg,Fe)SiO3 perovskite.

    (Communicated by Ikuo KUSHIRO, M.J.A.)
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