Ist Eka‐Quecksilber (Element 112) ein Metall der Gruppe 12?

Abstract

Die Synthese superschwerer Elemente stellt die Experimentalphysik vor eine große Herausforderung. Gleichzeitig werden dabei fundamentale Fragen zur Kernstruktur undstabilität aufgeworfen.[1] Es gab bereits große Erfolge bei der Herstellung der Elemente mit einer Ordnungszahl bis zu Z = 118 [2][3][4][5] und auch bei der Entwicklung einer echten Einzelatomchemie für die Elemente mit einer Ordnungszahl bis zu Z = 108 [6,7] [8,9] Das nächste superschwere Element, für das Einzelatomchemie in Vorbereitung ist, ist das Element 112 [10][11][12] (t 1/2 für 283 112 beträgt ungefähr 4 s [13] ), das auch als Eka-Quecksilber bekannt ist. Die chemischen Eigenschaften des Elements 112 sind umstritten: Frühere Vorhersagen reichen von quecksilberähnlichen Eigenschaften [16,17] bis hin zu einem Verhalten ähnlich dem der Edelgase, [8,18,19] letzteres wegen der starken relativistischen Kontraktion des 7s-Schale. Dementsprechend sind bereits Modellstudien durchgeführt worden, [10-12, 14, 15]

Thermochemical and Physical Properties of Element 112

“…[a] 52 +46 À7 [11] 30 AE 5 [20] 39 AE 3 [13] 67 [19] 110 AE 3 [16] 78 [20] 84 AE 10 [13] [a] This work. .…”

“…[a] 52 +46 À7 [11] 30 AE 5 [20] 39 AE 3 [13] 67 [19] 110 AE 3 [16] 78 [20] 84 AE 10 [13] [a] This work. Experimental parameters: a) gas flow 860 mL min À1 , temperature gradient from À24 to À184 8C; b) gas flow 890 mL min À1 , temperature gradient from 35 to À180 8C; c) gas flow 1500 mL min À1 , temperature gradient from 32 to À164 8C.…”

“…[11] Here we present new experimental results with an increased number of observed atoms that confirm these observations and improve their statistical significance. [16] Based on these strongly differing predictions, it is decisive for experimentalists to be able to distinguish in chemical experiments whether element 112 behaves more as a noble metal or as a noble gas. The increased stabilization of the atomic state of element 112 reveals a further enhancement of the relativistic effects with increasing atomic number Z in Group 12.…”

“…Accordingly, a noblegas-like behavior was postulated. [16] Based on these strongly differing predictions, it is decisive for experimentalists to be able to distinguish in chemical experiments whether element 112 behaves more as a noble metal or as a noble gas. [3] However, the spin-orbit coupling of the 6d orbitals is predicted to lead to an electronic ground state configuration with a 6d 5/2 orbital that is similar energetically and spatially to the 7s orbital, indicating that element 112 could be a noble transition metal [5,15] or even a semiconductor.…”

“…[3] However, the spin-orbit coupling of the 6d orbitals is predicted to lead to an electronic ground state configuration with a 6d 5/2 orbital that is similar energetically and spatially to the 7s orbital, indicating that element 112 could be a noble transition metal [5,15] or even a semiconductor. [16] Based on these strongly differing predictions, it is decisive for experimentalists to be able to distinguish in chemical experiments whether element 112 behaves more as a noble metal or as a noble gas. Therefore, investigation of gas adsorption properties of element 112 on metal surfaces has been suggested.…”