Studies of the halide complexation of element 105 in aqueous solution were performed on 34-s 262 Ha produced in the 249 Bk( ls O,5n) reaction. The 262 Ha was detected by measuring the fission and alpha activities associated with its decay and the alpha decays of its daughter, 4.3-s 258 Lr. Time-correlated pairs of parent and daughter alpha particles provided a unique identification of the presence of 262 Ha. About 1600 anion exchange separations of 262 Ha from HCl and mixed HC1/HF solutions were performed on a one-minute time scale. Reversed-phase micro-chromatographic columns incorporating triisooctyl amine (TIOA) on an inert support were used in the computer-controlled liquid chromatography apparatus, ARCA II. -.

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Seaborgium / Element 106 / Aqueous chemistry / HydrolysisSummary Seaborgium was previously eluted from cation exchange columns like its homologs molybdenum and tungsten in 0.1 Μ HNO3/5 Χ 10" 4 Μ HF. Its chemical form was presumably a neutral or anionic oxygen containing fluoride. However, species containing no fluoride such as SgOJ" could not be excluded. In order to verify that fluoride complexing played a role in the previous study, another series of cation exchange separations was performed with 7-s 265 Sg in which 0.1 Μ HN0 3 without HF was used as eluent. 265 Sg and ,69 W were produced simultaneously by bombarding a 248 Cm target containing Gd with 124 MeV 22 Ne ions. While 169 W was eluted from the cation exchange columns with an average chemical yield of 59%, no 265 Sg decay chain was detected in the eluent even though about 5 aacorrelations were expected. This non-tungsten like behaviour of seaborgium is tentatively attributed to its lower tendency to hydrolyze compared to that of tungsten. In the previous experiments with seaborgium in the presence of fluoride ions, neutral or anionic fluoride complexes, e.g., Sg0 2 F 2 or SgC^Fä, were likely to be formed and were eluted from the cation exchange columns.

The SISAK liquid-liquid extraction system was used to extract 4.0-s Rf. The Rf was produced in the reaction Pb(Ti, 1n)Rf with 237-MeV beam energy on target, separated in the Berkeley Gas-filled Separator (BGS) and transferred to a gas jet using the Recoil Transfer Chamber (RTC). The activity delivered by the gas jet was dissolved in 6-M HNO3 and Rf was extracted into 0.25-M dibutyl-phosphoric acid in toluene. This was the first time a transactinide, i.e., an element with Z•¬104, was extracted and unequivocally identified by the SISAK system. Thus, this pilot experiment demonstrates that the fast liquid-liquid extraction system SISAK, in combination with liquidscintillation detectors, can be used for investigating the chemical properties of the transactinides. The extraction result is in accordance with the behaviour shown by the Rf group IV homologues Zr and Hf.