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Journal Articles

Fluoride complexation of element 104, rutherfordium

Haba, Hiromitsu*; Tsukada, Kazuaki; Asai, Masato; Toyoshima, Atsushi; Akiyama, Kazuhiko; Nishinaka, Ichiro; Hirata, Masaru; Yaita, Tsuyoshi; Ichikawa, Shinichi; Nagame, Yuichiro; et al.

Journal of the American Chemical Society, 126(16), p.5219 - 5224, 2004/04

 Times Cited Count:42 Percentile:73.39(Chemistry, Multidisciplinary)

Fluoride complexation of element 104, rutherfordium (Rf), produced in the $$^{248}$$Cm($$^{18}$$O,5n)$$^{261}$$Rf reaction has been studied by anion-exchange chromatography on an atom-at-a-time scale. The anion-exchangechromatographic behavior of Rf was investigated in 1.9-13.9 M hydrofluoric acid together with those of the group-4 elements Zr and Hf produced in the $$^{18}$$O-induced reactions on Ge and Gd targets, respectively. It was found that the adsorption behavior of Rf on anion-exchange resin is quite different from those of Zr and Hf, suggesting the influence of relativistic effect on the fluoride complexation of Rf.

Oral presentation

Electrolytic reduction studies of Mo and W towards the reduction of seaborgium

Toyoshima, Atsushi; Asai, Masato; Attallah, M. F.*; Goto, Naoya*; Gupta, N. S.*; Haba, Hiromitsu*; Huang, M.*; Kanaya, Jumpei*; Kaneya, Yusuke; Kasamatsu, Yoshitaka*; et al.

no journal, , 

Towards electrolytic reduction of Sg, batch-wise electrolytic reduction of carrier-free $$^{93m}$$Mo and $$^{176,181}$$W radiotracers was studied using a flow electrolytic column (FEC). The electrolyzed samples from a FEC were chemically analyzed by solvent extraction with TOA and HDEHP to separate and identify reduced species from the stable Mo(VI) and W(VI) ones based on their different extraction behavior. $$^{93m}$$Mo and $$^{176, 181}$$W were applied as radiotracers. We also performed cyclic voltammetry and UV/Vis absorption spectrometry of macro amounts of Mo and W in acidic solutions to obtain information on redox reactions of these elements under given conditions. In the conference, the present status of the preparatory reduction experiments with Mo and W will be presented.

Oral presentation

Electrolytic reduction of Mo and W as lighter homologues of seaborgium

Toyoshima, Atsushi; Miyashita, Sunao*; Oe, Kazuhiro*; Kitayama, Yuta*; Lerum, H. V.*; Goto, Naoya*; Kaneya, Yusuke; Komori, Yukiko*; Mitsukai, Akina*; Vascon, A.; et al.

no journal, , 

no abstracts in English

Oral presentation

Developments towards aqueous phase chemistry of transactinide elements

Toyoshima, Atsushi; Oe, Kazuhiro*; Asai, Masato; Attallah, M. F.*; Goto, Naoya*; Gupta, N. S.*; Haba, Hiromitsu*; Kaneko, Masashi*; Kaneya, Yusuke; Kasamatsu, Yoshitaka*; et al.

no journal, , 

Due to short half-lives less than 10 s and extremely low production rates, transactinide elements heavier than seaborgium (Sg) are produced on an atom per hour scale. Therefore, a continuous rapid chemistry assembly is required to study aqueous-phase chemistry of these heaviest elements. In the present study, we started developments of a continuous chemistry assembly. Our first attempt was made in on-line experiments with Mo and W, lighter homologs of Sg, to optimize a chemistry assembly consisting of a newly developed membrane degasser as an interface between gas-jet and aqueous phase, a flow electrolytic column apparatus utilized to control oxidation states of Mo and W ions, and the continuous liquid-liquid extraction apparatus of SISAK for separation. In the conference, present status of the developments will be presented.

Oral presentation

Extraction behavior of Mo and W from H$$_{2}$$SO$$_{4}$$ into toluene with Aliquat336 as model experiments for seaborgium (Sg)

Mitsukai, Akina; Toyoshima, Atsushi; Kaneya, Yusuke; Oe, Kazuhiro*; Sato, Daisuke*; Goto, Naoya*; Tsuto, Shohei*; Komori, Yukiko*; Murakami, Masashi*; Haba, Hiromitsu*; et al.

no journal, , 

We report on the extraction behavior of carrier-free radioisotopes $$^{93m}$$Mo and $$^{181}$$W, which are lighter homologs of Sg, produced at the RIKEN K70 AVF cyclotron, in the H$$_{2}$$SO$$_{4}$$-Aliquat336 system. Results of the extraction experiments showed that the distribution ratios, ${it D}$, of Mo and W decrease up to $$sim$$3 M as increasing [H$$_{2}$$SO$$_{4}$$]. This is probably due to protonation reactions of hydrolyzed Mo and W species. In $$>$$ $$sim$$3 M H$$_{2}$$SO$$_{4}$$, the ${it D}$ values of W and Mo showed sharp increases. Based on the slope analysis separately carried out, it was suggested that hydrolyzed species of [HMO$$_{4}$$]$$^{-}$$ (M = Mo and W) are extracted in less than $$sim$$3 M [H$$_{2}$$SO$$_{4}$$], while anionic sulphate complexes of [MO$$_{2}$$(SO$$_{4}$$)$$_{2}$$]$$^{2-}$$ are formed in more than [H$$_{2}$$SO$$_{4}$$]$$>$$$$sim$$5 M.

Oral presentation

Extraction behavior of Mo and W from H$$_{2}$$SO$$_{4}$$ with Aliquat336 as homologues of seaborgium (Sg)

Mitsukai, Akina; Toyoshima, Atsushi; Asai, Masato; Tsukada, Kazuaki; Sato, Tetsuya; Kaneya, Yusuke; Takeda, Shinsaku*; Nagame, Yuichiro; Komori, Yukiko*; Murakami, Masafumi*; et al.

no journal, , 

We have started studying sulphate-complex formation of a transactinide element, seaborgium (Sg). In this study, we report on the extraction behavior of carrier-free radioisotopes $$^{93m}$$Mo and $$^{181}$$W which are lighter homologs of Sg, from aqueous H$$_{2}$$SO$$_{4}$$ solution with amine extractant, Aliquat336, dissolved in toluene by a batch method. These radioisotopes were produced in the $$^{nat}$$Zr($$alpha$$,${it 2}$)$$^{93m}$$Mo and $$^{181}$$Ta(${it d}$,x${it n}$)$$^{181}$$W reactions at the RIKEN K70 AVF cyclotron. Results of the extraction experiments showed that the distribution ratios of Mo and W increase sharply above ~3.0 M H$$_{2}$$SO$$_{4}$$. Based on the slope analysis, it was indicated that anionic sulphate-complex of [MO$$_{2}$$(SO$$_{4}$$)$$_{2}$$]$$^{2-}$$ (M = Mo, W) are formed in $$>$$ 5 M H$$_{2}$$SO$$_{4}$$. These results suggest that the present system is applicable to the extraction of Sg.

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