Seminar Details

“Chemistry of the Heaviest Elements”

Scott Suchyta, NSCL
Thursday, January 12, 11:00 AM - Research Discussion
NSCL Lecture Hall
Please note the special location.

Simple predictions of many chemical properties can be determined based on the location of an element on the periodic table. As atomic number increases, relativistic electron effects become important and may significantly alter a heavy element’s chemical behavior, causing divergence from expectations derived from periodic trends. Transactnide chemistry seeks to determine the degree to which the heaviest elements act according to their positions on the periodic table. Element 112 (copernicium) and element 114 (flerovium) have recently been studied in gas-phase chemistry experiments [1, 2]. After production of the isotopes of interest, volatile reaction products were separated from non-volatile products using the In situ Volatilization and Online detection (IVO) gas chromatographic separation system [3]. The heavy reaction products were detected by the Cryo-OnLine Detector (COLD) that consists of 32 pairs of silicon detectors of which half the detectors have a gold coating [2]. The enthalpies of sublimation of elements 112 and 114 have been determined as quantitative measurements of their volatilities. The enthalpy of sublimation of element 112, ΔHsubl(E112), has been determined to be 38+10-12 kJ mol-1, which suggests it behaves similarly to other members of Group 12 of the periodic table [1]. Although the results are somewhat controversial, in a separate experiment, ΔHsubl(E114) was determined to be 23+22-8 kJ mol-1, which indicates that unlike other members of Group 14, element 114 is inert, similar to a noble gas [2]. [1] R. Eichler et al., Nature (London) 447, 72 (2007). [2] R. Eichler et al., Radiochim Acta 98, 133 (2010). [3] Ch.E. Düllmann et al., Nucl. Instrum. Methods Phys. Res., Sect. A 479 631 (2002).