AUTHOR=Yakushev A. , Khuyagbaatar J. , Düllmann Ch. E. , Block M. , Cantemir R. A. , Cox D. M. , Dietzel D. , Giacoppo F. , Hrabar Y. , Iliaš M. , Jäger E. , Krier J. , Krupp D. , Kurz N. , Lens L. , Löchner S. , Mokry Ch. , Mošať P. , Pershina V. , Raeder S. , Rudolph D. , Runke J. , Sarmiento L. G. , Schausten B. , Scherer U. , Thörle-Pospiech P. , Trautmann N. , Wegrzecki M. , Wieczorek P. 

TITLE=Manifestation of relativistic effects in the chemical properties of nihonium and moscovium revealed by gas chromatography studies

JOURNAL=Frontiers in Chemistry

VOLUME=12

YEAR=2024

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2024.1474820

DOI=10.3389/fchem.2024.1474820

ISSN=2296-2646

ABSTRACT=<p>Chemical reactivity of the superheavy elements nihonium (Nh, element 113) and moscovium (Mc, element 115) has been studied by the gas-solid chromatography method using a new combined chromatography and detection setup. The Mc isotope, <sup>288</sup>Mc, was produced in the nuclear fusion reaction of <sup>48</sup>Ca ions with <sup>243</sup>Am targets at the GSI Helmholtzzentrum Darmstadt, Germany. After isolating <sup>288</sup>Mc ions in the gas-filled separator TASCA, adsorption of <sup>288</sup>Mc and its decay product <sup>284</sup>Nh on silicon oxide and gold surfaces was investigated. As a result of this work, the values of the adsorption enthalpy of Nh and Mc on the silicon oxide surface were determined for the first time, <inline-formula id="inf1"><mml:math id="m1" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mo>−</mml:mo><mml:mo>∆</mml:mo><mml:msubsup><mml:mi>H</mml:mi><mml:mtext>ads</mml:mtext><mml:msub><mml:mtext>SiO</mml:mtext><mml:mn>2</mml:mn></mml:msub></mml:msubsup><mml:mrow><mml:mfenced open="(" close=")" separators="|"><mml:mrow><mml:mtext>Mc</mml:mtext></mml:mrow></mml:mfenced></mml:mrow><mml:mo>=</mml:mo><mml:msubsup><mml:mn>54</mml:mn><mml:mrow><mml:mo>−</mml:mo><mml:mn>5</mml:mn></mml:mrow><mml:mrow><mml:mo>+</mml:mo><mml:mn>11</mml:mn></mml:mrow></mml:msubsup></mml:mrow></mml:math></inline-formula> kJ/mol and <inline-formula id="inf2"><mml:math id="m2" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mo>−</mml:mo><mml:mo>∆</mml:mo><mml:msubsup><mml:mi>H</mml:mi><mml:mtext>ads</mml:mtext><mml:msub><mml:mtext>SiO</mml:mtext><mml:mn>2</mml:mn></mml:msub></mml:msubsup><mml:mrow><mml:mfenced open="(" close=")" separators="|"><mml:mrow><mml:mtext>Nh</mml:mtext></mml:mrow></mml:mfenced></mml:mrow><mml:mo>=</mml:mo><mml:msubsup><mml:mn>58</mml:mn><mml:mrow><mml:mo>−</mml:mo><mml:mn>3</mml:mn></mml:mrow><mml:mrow><mml:mo>+</mml:mo><mml:mn>8</mml:mn></mml:mrow></mml:msubsup></mml:mrow></mml:math></inline-formula> kJ/mol (68% c.i.). The obtained −Δ<italic>H</italic><sub>ads</sub> values are in good agreement with results of advanced relativistic calculations. Both elements, Nh and Mc, were shown to interact more weakly with the silicon oxide surface than their lighter homologues Tl and Bi, respectively. However, Nh and Mc turned out to be more reactive than the neighbouring closed-shell and quasi-closed-shell elements copernicium (Cn, element 112) and flerovium (Fl, element 114), respectively. The established trend is explained by the influence of strong relativistic effects on the valence atomic orbitals of these elements.</p>