First Aqueous Chemistry with Seaborgium (Element 106)

Chemical separations of element 106 (seaborgium, Sg) were performed in aqueous solutions. The isotopes 265 Sg and 266 Sg, produced in the 248 Cm+ 22 Ne reaction, were continuously transported to the automated liquid chromatography system ARCA. In 0.1 M HNO 3 /5× 10 -4 M HF, Sg was found to be eluted from cation-exchange columns together with the hexavalent Mo- and W-ions, while hexavalent U-ions were strongly retained on the column. Seaborgium was detected by measuring correlated α-decays of the daughter isotopes. For the isotope 266 Sg, we have evidence for a spontaneous fission branch. The chemical results show that the most stable oxidation state of Sg in aqueous solution is +6, and that like its homologs Mo and W, Sg forms neutral or anionic oxo- or oxohalide-compounds. Sg exhibits properties very characteristic of group 6 elements, and does not show U-like properties. A second, very recent experiment, performed with pure 0. 1 M HNO 3 , gave evidence that the F - -anions contributed significantly to the complex formation in the first experiment.