The Gas Phase Oxide and Oxyhydroxide Chemistry of Trace Amounts of Rhenium

Abstract

SummaryIn preparation of experiments to investigate the chemical properties of bohrium (Bh, element 107) the behaviour of Re, its lighter homologue in group 7, was studied in different oxidizing chemical systems. The adsorption data of Re oxide and oxyhydroxide Compounds on quartz surfaces were evaluated from results of thermochromatography experiments and confirmed in isothermal gas chromatography experiments applying 1 cm as Standard state for the simple gas adsorption process: An on-line Separation method for oxides and oxyhydroxides of Short lived Re isotopes using isothermal high temperature gassolid adsorption chromatography was deveioped. Separation yields and times of group 7 Clements from lanthanides (model for actinides), poIonium and bismuth were determined using the model isotopes and ^"Bi. An updated correlation function between the microscopic adsorption enthalpy and the macroscopic Sublimation enthalpy was calculated from the experimental adsorption data of this work and literature data.

Chemistry of Superheavy Elements

“…However, test experiments with Re have shown that the oxy hydroxide system has some potential for future studies of Bh, especially if volatile Po, Pb, and Bi contaminations, which mask the a-spectra and limit the sensitivity, can be avoided by using a physical preseparator. [234][235][236] To date, the only information on chemical properties of Bh was obtained in gas chromatographic experiments [99] on the oxy chlorides which were performed by Eichler and coworkers at the PSI Philips cyclotron in Villigen. Extensive tests with Tc and Re tracer activities had been performed previously.…”

Chemical studies of elements with Z⩾ 104 in gas phase

“…Element 108, hassium, was synthesized for the first time in 1984 using the reaction 58 Fe + 208 Pb. The identification was based on observation of three decay chains, which were assigned to 265 Hs [60].…”

“…The identification was based on observation of three decay chains, which were assigned to 265 Hs [60]. Only one -decay chain was measured in the irradiation of 207 Pb with 58 Fe. The measured event was assigned to the even-even isotope 264 Hs [61].…”

“…The calculated values for the adsorption on quartz and ice are very similar and in very good agreement with values obtained in experiments in all cases. In many works the empirical correlation between −ΔH ads and ΔH sub has been described by a linear approximation [58,92]. Considering that ΔH sub is proportional to E diss , −ΔH ads should be proportional to (E ads ) 2 .…”

Model Studies for the Separation and Identification of Element 107 (Bohrium, Bh): Ion Exchange and Precipitation Experiments with Tc, Re, Nb and Ta Nuclides from HNO3/HF containing Aqueous Solution

“…However, the following application of this system with the aim to search for new bohrium isotopes in the reaction 254 Es+ 16 0 failed [7], in the opinion of the authors caused either by low cross sections or short half-lives of the desired isotopes. Recent model studies deal with gas chromatographic systems using volatile oxo, hydroxo or oxochloride compounds [8,9].…”