No abstract

Formation of anionic fluoride-complexes of element 104, rutherfordium, produced in the 248 Cm( 18 O, 5n) 261 Rf reaction was studied by anion-exchange on an atom-at-a-time scale. It was found that the hexafluoro complex of Rf, [RfF 6 ] 2− , was formed in the studied fluoride ion concentrations of 0.0005-0.013 M. Formation of [RfF 6 ] 2− was significantly different from that of the homologues Zr and Hf, [ZrF 6 ] 2− and [HfF 6 ] 2− ; the evaluated formation constant of [RfF 6 ] 2− is at least one-order of magnitude smaller than those of [ZrF 6 ] 2− and [HfF 6 ] 2− .

The extraction behavior of rutherfordium (Rf) into tributylphosphate (TBP) from hydrochloric acid (HCl) has been studied together with those of the lighter group-4 elements Zr and Hf. The extractability of