[en] The valence-delocalization in mixed-valence binuclear ferrocene derivatives is investigated by using several physicochemical results. It is demonstrated that the mixed-valence state is controlled by the environment in the solid state. The mechanism of the valence-delocalization in 1',1'''-diethylbiferrocenium triiodide is discussed. The difference between the valence-delocalization accompanied by the symmetry change of the counter anion and the valence-delocalization without connection with the symmetry of the counter anion is discussed. The results are compared with those of oxo-centered trinuclear iron carboxylates. (orig.)

[en] The experimental study of the uranium-lignite association has been investigated at different temperatures from 20 to 400⁰C. Fixation of uranyl species by the lignite (45 to 250⁰C) and reduction of them to uraninite (120 to 400⁰C) were observed. The reduction of uranium is accompanied by dehydrogenation of the lignite

[en] Safety Measures Committee on Radioactive Materials Originated from Nuclear Power Station accident investigates the effectiveness of various chemical decontamination methods. Dissolved state of Cs 137 in sea water in different paddy water and soils was investigated with reference to the dependence of radioactivity concentrations on soils of paddy fields. Transport of Cs 137 from upstream field toward downstream fields, root absorption and a stem or a stalk through which Cs easily moves were also studied. (S. Ohno)

[en] A pore water sampler has been designed and constructed for in situ squeezing of pore waters from marine sediments at different twelve depths including overlying bottom water. The instrument consist of two rigidly connected parts, a 1-m length of SUS tubing (5-cm o.d.) fitted with a sharp tip, and an open work superstructure, that protects parts such as twelve SUS cylinders, tubing connections, etc. Each of the twelve squeezing systems consists of a squeezing port of 2-cm diameter, a 10-m length of teflon tubing, and a spring-loaded cylinder providing the suction. It is lowered into the bottom and full 1-m penetration triggers the system and initiates sampling. At each of the sampling ports water is drawn through a polyethylene porous disk and a filter paper into the teflon tubing storage system and the cylinder. The instrument was operated on board of the R/V Tokai Daigaku Maru II in Shimizu Port and pore waters were obtained. Chemical compositions of the pore waters indicate that microbial sulfate reduction takes place in the sediment of Shimizu Port. The test suggests that the configuration of the instrument could be successful but these are several points to be improved. (author)

[en] In order to revisit the kinetics of amino acid transformation in the chemical evolution, a series of hydrothermal experiments has been conducted for threonine (Thr) solution. Thr transformed into glycine (Gly) and other products including peptides and polymers at 121 to 160degC. The thr → Gly decomposition rate (k₁) is different from apparent Thr decreasing rate (k), because of the presence of other side reactions. (author)

No abstract available

[en] Applications of Mössbauer spectrometry, which reveals a detail in stepwise spin transition in binuclear, trinuclear, and tetranuclear complex, are introduced to the study of spin-crossover phenomena. The appearance of spin-crossover phenomenon by enclathrating guest molecule in the assembled complex is introduced. A variety of assembled structures are obtained by changing conformer of bridging ligand. The reversible structural change of host framework triggered by desorption and adsorption of guest benzene molecules was also introduced. (author)

[en] The formation of α₂-Sn has been investigated by ¹¹⁹Sn Moessbauer spectroscopy and X-ray powder diffraction. The α₂-Sn form obtained in reduction of SnCl₂ ethanol solution indicates the isomer shift δ=-3.9±0.1 mm/s relative to CaSnO₃ and no quadrupole splitting. The XRD patterns suggest that two types of α₂-Sn forms exist with different lattice parameters of a=6.06 A and 5.65 A, and contain some impurities in their crystal lattices. (orig.)

[en] Assembled coordination complexes have a variety of assembled structures depending on the bridging ligand. When the bridging ligand is flexible, more variety of assembled structure is expected depending on the conformer of the ligand. 1,2-Bis (4-pyridyl) ethane (bpa) has anti-gauche conformer and 1,3-bis (4-pyridyl) propane (bpp) has more variety of conformer. A variety of assembled structures were obtained by changing conformer of bpa. The appearance of spin-crossover phenomenon by enclathrating guest molecule in the assembled complexes of bpa was introduced. The assembled complex, [Fe(NCBH₃)₂(bpa)₂] · biphenyl was synthesized, the skeleton of which was a 1D chain. Several 1D chains gathered together to form 1D chain sheet. The 1D chain sheet was stacked spirally to form novel spiral assembly. The assembly showed a stepwise spin-crossover phenomenon. The reversible structural change of host framework triggered by desorption and adsorption of guest benzene molecules was also introduced in bpp complexes. (author)

[en] The stability of methyl radicals formed in synthetic methane hydrate by γ-ray irradiation at 77K was studied at 200-273 K and 10 MPa. The methylradicals decayed under these conditions, despite the stability of methane hydrate, and changed into other molecules that could not be detected by electron spin resonance (ESR). Decay products were investigated by gas cell infrared (IR) spectroscopy by measuring the decomposed gas from the γ-irradiated methane hydrate. Only ethane molecules were detected from the irradiated sample, while these were absent in an unirradiated sample. The molar ratio of ethane to methane (C₂H₆/CH₄) was 12±1 ppm, which did not contradict with that of methyl radical to methane (CH₃^·/CH₄) in the literature. Hence, most of the methyl radicals generated by irradiation were supposed to be transformed to ethane in methane hydrate. (author)