SuperHeavy Elements (SHE) provide unique possiblities to study the influence
of relativistic effects on the electronic structure. However, until
recently, only a limited number of thermally stable, inorganic compounds
of SHEs have been accessible due to technical restrictions [1]. Thanks to
the approach of physical preseparation [2], many limitations could be
overcome. We have developed in experiments at the TRIGA reactor in Mainz
and at the TASCA separator at GSI a method to synthesize carbonyl
complexes of short-lived isotopes [3]. This method has now been
successfully applied at the GARIS separator at RIKEN to synthesize for the
first time a carbonyl complex of a superheavy element - Seaborgium
hexacarbonyl [4].
265Sg was synthesized in the reaction 248Cm(22Ne,5n), separated from the
primary beam, and was thermalized in a He/CO mixture behind GARIS. This
way it formed a volatile complex and was transported in the gas stream to
a COMPACT gas-chromatography detector[6], where its adsorption on SiO2 was
studied. The chemical properties of seaborgium were compared to its
lighter homologs molybdenum and tungsten. The combination of physical and
chemical separation allowed studying the decay of 265Sg under background-
free conditions. Our results indicate the observation of Sg(CO)6 and
provide new information on the nuclear properties of 265Sg.
Experimental details and results will be presented in the seminar. An
outlook on future applications of CO chemistry in superheavy element
research and as a new tool for background-free decay spectroscopy will be
given.
[1] A. Tuerler and V. Pershina, Chem. Rev. 113, 1237-1312 (2013).
[2] Ch.E. Duellmann et al., Nucl. Instr. Meth. A 551, 528539 (2005).
[3] J. Even et al., Inorg.Chem. 51, 6431-6422 (2012).
[4] J. Even et al, accepted for publication in Science (2014).
[5] H. Haba et al., Phys. Rev. C 85, 024611(2012).
[6] A. Yakushev et al., Inorg. Chem. 53, 1624 (2014).
