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Pershina V. Relativity in the electronic structure of the heaviest elements and its influence on periodicities in properties. RADIOCHIM ACTA 2019. [DOI: 10.1515/ract-2018-3098] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Theoretical chemical studies demonstrated crucial importance of relativistic effects in the physics and chemistry of superheavy elements (SHEs). Performed, with many of them, in a close link to the experimental research, those investigations have shown that relativistic effects determine periodicities in physical and chemical properties of the elements in the chemical groups and rows of the Periodic Table beyond the 6th one. They could, however, also lead to some deviations from the established trends, so that the predictive power of the Periodic Table in this area may be lost. Results of those studies are overviewed here, with comparison to the recent experimental investigations.
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Affiliation(s)
- Valeria Pershina
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstr. 1 , D-64291 Darmstadt , Germany
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Abstract
Abstract
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.
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Affiliation(s)
- M. Schädel
- Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan / GSI Helmholtz Center for Heavy Ion Research, 64291 Darmstadt, Germany
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Türler A, Pershina V. Advances in the Production and Chemistry of the Heaviest Elements. Chem Rev 2013; 113:1237-312. [DOI: 10.1021/cr3002438] [Citation(s) in RCA: 170] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Andreas Türler
- Laboratory
of Radiochemistry
and Environmental Chemistry, Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
- Laboratory of Radiochemistry
and Environmental Chemistry, Department Biology and Chemistry, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
| | - Valeria Pershina
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstrasse
1, D-64291 Darmstadt, Germany
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Abstract
Abstract
The experimental techniques developed to perform rapid chemical separations of the heaviest elements in the aqueous phase are presented. In general, these include transport of the nuclear reaction products to a separation device by the gas-jet technique and dissolution in an aqueous solution containing inorganic ligands for complex formation. The complexes are chemically characterized by a partition method which can be liquid–liquid extraction, ion-exchange- or reversed-phase extraction chromatography. The separated fractions are quickly evaporated to dryness for the preparation of samples for α-particle spectroscopy. Comments are given on the special situation in which chemistry has to be studied with single atoms. Theoretical predictions of chemical properties are compared to the presently known chemical behaviour of rutherfordium, Rf (element 104), dubnium, Db (element 105), seaborgium, Sg (element 106), and hassium, Hs (element 108) and to that of their lighter homologs in the Periodic Table in order to assess the role of relativistic effects in the chemistry of the heaviest elements.
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Samadani F, Alstad J, Bjornstad T, Stavsetra L, Omtvedt JP. Development of a SISAK extraction system for chemical studies of element 108, hassium. RADIOCHIM ACTA 2010. [DOI: 10.1524/ract.2010.1787] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abstract
A liquid–liquid extraction system suitable for studies of chemical properties of Hs (element 108), in the form of HsO4, was developed using γ-emitting isotopes of its homologue Os. The system is targeted for the fast on-line extraction system SISAK, which operates in a continuous manner and is suitable for liquid-phase studies of transactinide elements. The distribution of OsO4 between various dilute NaOH solutions and toluene was studied. Both batch and SISAK on-line experiments were performed to develop an appropriate system. From analysis of the extraction curves equilibrium constants for the formation of the presumed complexes, Na[OsO4(OH)] and Na2[OsO4(OH)2], were obtained: K
1=(1±0.5)×104 and K
2=12±8, respectively. The SISAK system includes a liquid-scintillation detection system for α measurements. Due to quenching effects it is not possible to perform direct measurement of the aqueous phase α´s. Therefore, a two-stage extraction method that provides an indirect measurement of the activity in the aqueous phase was developed as part of the proposed system for Hs: Acidification of the raffinate from the first stage result in recovery of OsO4, which is highly extractable into toluene. The yield of extraction in the second step, from 0.01 M NaOH solution after acidification with H2SO4 solution, was (90±3) %.
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Affiliation(s)
| | - J. Alstad
- University of Oslo, Dept. of Chemistry, Oslo, Norwegen
| | - T. Bjornstad
- University of Oslo, Department of Chemistry, Oslo, Norwegen
| | - L. Stavsetra
- University of Oslo, Department of Chemistry, Oslo, Norwegen
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Pershina V. Electronic Structure and Chemistry of the Heaviest Elements. CHALLENGES AND ADVANCES IN COMPUTATIONAL CHEMISTRY AND PHYSICS 2010. [DOI: 10.1007/978-1-4020-9975-5_11] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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