Topic
Copernicium
About: Copernicium is a research topic. Over the lifetime, 15 publications have been published within this topic receiving 522 citations. The topic is also known as: Cn & element 112.
Papers
TL;DR: A more reliable chemical characterization of element 112, involving the production of two atoms of 283112 through the alpha decay of the short-lived 287114 and the adsorption of the two atoms on a gold surface, finds that element 112 is very volatile and, unlike radon, reveals a metallic interaction with the gold surface.
Abstract: Element 112 was discovered at the Heavy Ion Research Laboratory in Darmstadt, Germany in 1996 A decade on, and some of its chemical properties have now been determined Irradiation of plutonium-242 with intense calcium-48 beams for three weeks produced two atoms of element 112 (not yet officially named, but commonly called ununbium), and that's enough to do some chemistry on if you are quick Chemically ununbium behaves as a typical element of the group 12 in the periodic table (which it shares with Zn, Cd and Hg) It is very volatile and forms a metallic bond with a gold surface An experiment has scrutinized two atoms of element 112, finding that it is very volatile and forms a metallic bond with a gold surface These characteristics establish element 112 as a typical element of group 12 The heaviest elements to have been chemically characterized are seaborgium1 (element 106), bohrium2 (element 107) and hassium3 (element 108) All three behave according to their respective positions in groups 6, 7 and 8 of the periodic table, which arranges elements according to their outermost electrons and hence their chemical properties However, the chemical characterization results are not trivial: relativistic effects on the electronic structure of the heaviest elements can strongly influence chemical properties4,5,6 The next heavy element targeted for chemical characterization is element 112; its closed-shell electronic structure with a filled outer s orbital suggests that it may be particularly susceptible to strong deviations from the chemical property trends expected within group 12 Indeed, first experiments concluded that element 112 does not behave like its lighter homologue mercury7,8,9 However, the production and identification methods10,11 used cast doubt on the validity of this result Here we report a more reliable chemical characterization of element 112, involving the production of two atoms of 283112 through the alpha decay of the short-lived 287114 (which itself forms in the nuclear fusion reaction12 of 48Ca with 242Pu) and the adsorption of the two atoms on a gold surface By directly comparing the adsorption characteristics of 283112 to that of mercury and the noble gas radon, we find that element 112 is very volatile and, unlike radon, reveals a metallic interaction with the gold surface These adsorption characteristics establish element 112 as a typical element of group 12, and its successful production unambiguously establishes the approach to the island of stability of superheavy elements through 48Ca-induced nuclear fusion reactions with actinides
307 citations
TL;DR: A gas-solid chromatography study of the adsorption of Fl on a Au surface points to the formation of a metal-metal bond of Fl with Au, the least reactive element in the group, but still a metal.
Abstract: The electron shell structure of superheavy elements, i.e., elements with atomic number Z ≥ 104, is influenced by strong relativistic effects caused by the high Z. Early atomic calculations on element 112 (copernicium, Cn) and element 114 (flerovium, Fl) having closed and quasi-closed electron shell configurations of 6d107s2 and 6d107s27p1/22, respectively, predicted them to be noble-gas-like due to very strong relativistic effects on the 7s and 7p1/2 valence orbitals. Recent fully relativistic calculations studying Cn and Fl in different environments suggest them to be less reactive compared to their lighter homologues in the groups, but still exhibiting a metallic character. Experimental gas–solid chromatography studies on Cn have, indeed, revealed a metal–metal bond formation with Au. In contrast to this, for Fl, the formation of a weak bond upon physisorption on a Au surface was inferred from first experiments. Here, we report on a gas–solid chromatography study of the adsorption of Fl on a Au surface....
122 citations
TL;DR: A test bench is established to challenge the validity and predictive power of modern fully relativistic quantum chemical models and to probe ‘relativistically’ influenced chemical properties and the architecture of the periodic table at its farthest reach.
Abstract: The quest for superheavy elements (SHEs) is driven by the desire to find and explore one of the extreme limits of existence of matter. These elements exist solely due to their nuclear shell stabilization. All 15 presently 'known' SHEs (11 are officially 'discovered' and named) up to element 118 are short-lived and are man-made atom-at-a-time in heavy ion induced nuclear reactions. They are identical to the transactinide elements located in the seventh period of the periodic table beginning with rutherfordium (element 104), dubnium (element 105) and seaborgium (element 106) in groups 4, 5 and 6, respectively. Their chemical properties are often surprising and unexpected from simple extrapolations. After hassium (element 108), chemistry has now reached copernicium (element 112) and flerovium (element 114). For the later ones, the focus is on questions of their metallic or possibly noble gas-like character originating from interplay of most pronounced relativistic effects and electron-shell effects. SHEs provide unique opportunities to get insights into the influence of strong relativistic effects on the atomic electrons and to probe 'relativistically' influenced chemical properties and the architecture of the periodic table at its farthest reach. In addition, they establish a test bench to challenge the validity and predictive power of modern fully relativistic quantum chemical models.
81 citations
TL;DR: Owing to the very small half-lives of the seelements, experiments have been performed to investigate whether the Periodic Table is useful for categorization and the question of whether the element categorization is correct is posed.
Abstract: toexploretheiroftenanomalousbehavior.However, the detection of these elements relies on a goodunderstandingoftheirchemicalandphysicalproperties.Forthetransactinideseries,whichbeginswithrutherfor-dium (Z=104), experiments have been performed to cor-rectlyplacetheelementsinthePeriodicTableandtoaddressthequestionofwhetherthePeriodicTableisevenusefulfortheir categorization. Owing to the very small half-lives oftheseelements(t
72 citations
TL;DR: Bulk Cn is found to be bound by dispersion and to exhibit a large band gap of 6.4 eV, which is consistent with a noble‐gas‐like character and in the non‐relativistic limit, Cn appears as a common Group 12 metal.
Abstract: The chemical nature and aggregate state of superheavy copernicium (Cn) have been subject of speculation for many years. While strong relativistic effects render Cn chemically inert, which led Pitzer to suggest a noble-gas-like behavior in 1975, Eichler and co-workers in 2008 reported substantial interactions with a gold surface in atom-at-a-time experiments, suggesting a metallic character and a solid aggregate state. Herein, we explore the physicochemical properties of Cn by means of first-principles free-energy calculations, which confirm Pitzer's original hypothesis: With predicted melting and boiling points of 283±11 K and 340±10 K, Cn is indeed a volatile liquid and exhibits a density very similar to that of mercury. However, in stark contrast to mercury and the lighter Group 12 metals, we find bulk Cn to be bound by dispersion and to exhibit a large band gap of 6.4 eV, which is consistent with a noble-gas-like character. This non-group-conforming behavior is eventually traced back to strong scalar-relativistic effects, and in the non-relativistic limit, Cn appears as a common Group 12 metal.
26 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2019 | 1 |
| 2018 | 1 |
| 2017 | 2 |
| 2015 | 1 |
| 2014 | 2 |
| 2012 | 2 |