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Toyoshima, Atsushi; Kasamatsu, Yoshitaka; Tsukada, Kazuaki; Asai, Masato; Kitatsuji, Yoshihiro; Haba, Hiromitsu*; Ishii, Yasuo; Tome, Hayato; Nishinaka, Ichiro; Oe, Kazuhiro*; et al.
no journal, ,
We present a characterization technique for heavy actinides with electrochemistry. An electrochemistry apparatus combined with a chromatographic separation technique was developed to identify oxidation states of the heavy actinides on an atom-at-a-time scale. Oxidation states of nobelium (No) in aqueous solution were studied using the apparatus. Nobelium-255 with a half-life of 3.1 min was produced in the 
Cm(
C, 5n) reaction at the JAEA tandem accelerator. Chromatographic behavior of No on a chemically modified electrode with Nafion perfluoronated ion-exchange resin was investigated in ammonium 
-hydroxyisobutyric acid solution. It has been found that No is bound in the most stable divalent state at low applied potentials while it exists as the trivalent ion at higher potentials, showing the electrochemical oxidation of No.
Yaita, Tsuyoshi; Kobayashi, Toru; Shiwaku, Hideaki; Okamoto, Yoshihiro; Akutsu, Kazuhiro; Suzuki, Shinichi
no journal, ,
Hybrid donor type ligand consistent of two aza-aromatic donors and an amide oxygen, N-alkyl-N-phenyl-1,10- phenanthroline-2-carboxamide (PTA) as ion recognition reagents for actinides, was successfully designed and synthesized. This compound presents a quite unique function never seen before, i.e., recognizes actinides (III, IV, VI) from lanthanides (III) in acidic solution. Generally, oxygen donor ligands show strong affinity to all actinides and lanthanides by electrostatic coupling, while nitrogen donor ligands recognize selectively trivalent actinides from lanthanides through covalent interaction. Therefore, this special property of the PTA is attributed to be an integrated compound by the two types of the ligands. In this presentation, mechanism for the recognition of trivalent actinides from lanthanides by syanchrotron based XAS, XES and RIXS will be also discussed.
Nagame, Yuichiro; Toyoshima, Atsushi; Ishii, Yasuo; Kasamatsu, Yoshitaka; Tome, Hayato; Asai, Masato; Tsukada, Kazuaki
no journal, ,
Chemical characterization of the transactinide elements, rutherfordium (Rf) and dubnium (Db) at JAEA (Japan Atomic Energy Agency) is presented. The transactinide nuclides 
Rf and 
Db were produced in the nuclear reactions Cm(
O,5
) and Cm(
F,5), respectively at the JAEA tandem accelerator. Ion-exchange behavior of Rf and Db together with their lighter homologues in HF/HNO
mixed solutions has been investigated with a rapid ion-exchange separation apparatus AIDA. It has been found that fluoride complexation of Rf is significantly different from that of the homologues. A large difference in the adsorption behavior of Db and the homologue Ta on the anion-exchange resin has been also observed. Fluoride complexation of Rf and Db will be briefly discussed.