The chemistry of the heaviest elementsThe transactinide elements known today and beyond

The newest elements in the periodic table represent the transactinides with atomic numbers starting from 104, rutherfordium. Their chemical properties are assumed to be largely influenced by relativistic effects in their electron structure induced by the high nuclear charge Z. These elements are produced artificially in heavy ion induced nuclear fusion reactions using large particle accelerators. The low production rates down to single atoms per week as well as their short half-lives challenge their chemical investigation on a one-atom-at-a-time level. We develop complete efficient and fast gas phase chemical investigation methods for the investigation of transactinides. We elaborate empirical thermochemical methods to predict properties of transactinides. Based on these predictions we design suitable gas chromatography setups using gas phase simulation tools. We work in large international collaborations with research institutions from Russia (FLNR) , Germany(GSI) , USA (LBNL, LLNL), China (IMP), Poland (ITE), Norway (SAFE/OCL), and Japan (RIKEN, JAEA) to determine gas phase chemical properties of transactinides. Our results are used for a more comprehensive understanding of extending the periodic table beyond known elements and for predicting properties for elements so far not in reach with currently available experimental techniques. We employ and develop an instrumentation pool applied for the most sensitive radioanalytical tasks. We use the PSI production facilities for radioactive tracer isotopes (SINQ Irradiation facilities). We are strongly involved in the Swiss radiochemical education at the University Bern (University of Bern).

• Chemical investigation of the elements 113 and Fl;
• Pure COLD - the new PSI pile-up rejection α- and SF- spectroscopy electronics;
• Development of a vacuum chromatography system for transactinide research:
  • hot catcher release experiments;
  • IVAC and diamond detectors;
• Development of stable intermetallic actinide targets for transactinide experiments;
• Investigation of the stability of transition metal carbonyl compounds for the investigation of light transactinides at low oxidation states;
• SEARCH - Release of radionuclei from liquid and solid lead bismuth eutectica;
• MeanCorN Measurement of neutron capture cross sections and determination of half-lives of short-lived cosmogenic radio-nuclides;

• First indications for a volatile element Fl;
  Radiochim. Acta 2010 98, 133.
• Chemical identification of element Cn as a very volatile group 12 element;
  Angew. Chem. Int. Ed. 2008, 47, 3262.
• First chemical characterization of Cn;
  Nature 2007, 447, 73.
• Hs a typical member of group 8 together with Fe, Ru, Os;
  Nature 2002, 418, 860.
• Bohrium was characterized to be chemically similar to group 7 elements;
  Nature 2000, 407, 63.
• The volatility of SgO₂Cl₂ determined;
  Angew. Chem. Int. Ed. 1999, 38, No. 15, 2212.
• First chemical identification of seaborgium;
  Nature 1997, 388, 55-57