Chemistry of superheavy elements

Abstract

Summary. The chemistry of superheavy elements -or transactinides from their position in the Periodic Table -is summarized. After giving an overview over historical developments, nuclear aspects about synthesis of neutron-rich isotopes of these elements, produced in hot-fusion reactions, and their nuclear decay properties are briefly mentioned. Specific requirements to cope with the one-atom-at-a-time situation in automated chemical separations and recent developments in aqueous-phase and gas-phase chemistry are presented. Exciting, current developments, first applications, and future prospects of chemical separations behind physical recoil separators ("pre-separator") are discussed in detail. The status of our current knowledge about the chemistry of rutherfordium (Rf, element 104), dubnium (Db, element 105), seaborgium (Sg, element 106), bohrium (Bh, element 107), hassium (Hs, element 108), copernicium (Cn, element 112), and element 114 is discussed from an experimental point of view. Recent results are emphasized and compared with empirical extrapolations and with fully-relativistic theoretical calculations, especially also under the aspect of the architecture of the Periodic Table.

Discovery of the elements with atomic numbers Z = 113, 115 and 117 (IUPAC Technical Report)

“…Wilk et al [35] sought to improve the separation scheme employed by Stoyer et al [26] and encountered Nb and Ta both evincing two behaviors which could not be explained although the authors did suspect that this was evidence for different speciation of both the Nb and Ta in the solutions employed. The existence of a variety of halide, oxyhalide, and hydroxyhalide forms for the heavy Group 5 elements has been acknowledged as a complicating factor in their chemistries [36][37][38]. The chemistry employed in the Z = 115 studies seeking to prove the identity of dubnium did not employ the same steps as in the definitive studies on the short-lived 113 from the 2n evaporation channel and subsequently a total of four inclusive chains from the 2n evaporation channel were found in 2013 [21].…”

Chemistry of the superheavy elements

“…Taking into account, collection and transport efficiencies including nuclear decay losses, between 10% and 80% of these short-lived nuclei become available for chemical investigations; for more details, see [9] and §4.…”

“…It is a great challenge, but it can also be very attractive and interesting, to master these tasks across all different scientific and technical disciplines [8][9][10][11][12]46].…”

“…Detailed recent studies, however, revealed a number of surprises [8][9][10][11][12][47][48][49]. In the following, liquid-phase fluoride complexation experiments will be sketched to demonstrate pronounced differences between Rf and its lighter homologues zirconium (Zr) and hafnium (Hf).…”

Fast chemical separations and laser mass spectrometry – tools for nuclear research

“…Recently fast chemical separation methods have predominantly been used for studies of the chemical behaviour of the transactinide elements. More details on this topic are presented in another article in this special issue [16].…”