Reactivity of Superheavy Elements Cn, Nh, and Fl and Their Lighter Homologues Hg, Tl, and Pb, Respectively, with a Gold Surface from Periodic DFT Calculations

Abstract

Adsorption energies of superheavy elements (SHEs) Cn, Nh, and Fl and their lighter homologues Hg, Tl, and Pb, respectively, on a Au(111) surface at different adsorbate coverages are predicted via periodic relativistic DFT calculations with the aim of assisting the outcome of related "one-atom-at-a-time" gas-phase chromatography experiments. In agreement with previous DFT studies with the use of a cluster model, the present results for large supercells are indicative of high volatility of Cn. Thus, this element should not interact with the regular Au(111) surface at room temperature but should adsorb on it in a vacancy. Fl should moderately interact with such a surface under ambient conditions, while Nh should be the most reactive element with respect to gold. All three elements should, however, reveal much lower reactivity toward gold than their lighter homologues. The reasons for this are the strong relativistic stabilization and contraction of the 7s and 7p AOs. The obtained trend in the adsorption energy, Nh ≫ Fl > Cn, enables one to easily separate these elements from each other, as well as from their lighter homologues using gold or gold/quartz surfaces.

Colloquium : Superheavy elements: Oganesson and beyond

“…Most recent adsorption studies of Cn and Fl on gold surfaces suggest that both elements bind weakly to the surface, i.e., −∆H ads (Au) (in kJ/mol) = 98±3 (Hg) (Soverna et al, 2005), 52 +4 −3 (Cn) (Eichler et al, 2008), ≥48 (Fl) (Yakushev et al, 2014), and 20 (Rn) (Soverna et al, 2005). This is in good agreement with the latest theoretical studies (Pershina, 2018;Pershina et al, 2009Pershina et al, , 2008aRampino et al, 2015). From an empirical relationship between ∆H ads (Au) and the cohesive energy of the bulk material E coh , one estimates E coh = 38 +10 −12 kJ/mol for Cn (Eichler et al, 2008).…”

The periodic table – an experimenter’s guide to transactinide chemistry

“…A noble gas-like behavior as suggested in 1975 [62] could be ruled out, though. Metallic properties still dominate the interaction of copernicium with noble metals in agreement with predictions from density functional theory (see [63] and references therein).…”

“…The interaction of TlOH with quartz is comparably strong as the interaction of the elemental state with this surface. This translates into a similar macroscopic volatility for Tl and TlOH, which is also deduced from recent relativistic calculations [63,66]. Therefore, it appears difficult to distinguish these chemical states also for Nh.…”

Oganesson ist ein Halbleiter: Über die relativitische Bandlückenkontraktion in den schwersten Edelgasen

“…Der Grund für den überraschend starken Rückgang der Bandlücke zwischen Rn und Og konnte dabei auf den Einfluss der besonders starken Spin‐Bahn‐Aufspaltung der 7p‐Valenzschale zurückgeführt werden. Diese Charakterisierung von Og kann helfen, zukünftige Einzelatom‐Adsorptionsexperimente zu entwerfen, während die Bandlücke von festem Rn prinzipiell experimentell zugänglich und damit überprüfbar ist, wie die Messung des Schmelzpunktes von Rn vor mehr als 100 Jahren zeigt …”