Pershina Valeria, Iliaš Miroslav
Helmholtz-Institut Mainz , Johannes Gutenberg-Universität , 55099 Mainz , Germany.
GSI Helmholtzzentrum für Schwerionenforschung , Planckstraße 1 , D-64291 Darmstadt , Germany.
Inorg Chem. 2019 Aug 5;58(15):9866-9873. doi: 10.1021/acs.inorgchem.9b00949. Epub 2019 Jul 9.
Adsorption energies, , of gaseous hydroxides of In, Tl, and the superheavy element Nh on surfaces of Teflon and gold are predicted using molecular and periodic relativistic DFT calculations. The ambition of the work is to assist related "one atom at a time" gas-phase chromatography experiments on the volatility of NhOH. The obtained low values of (MOH), where M = In, Tl, Nh, on Teflon should guarantee easy transportation of the molecules through the Teflon capillaries from the accelerator to the chemistry setup. Straightforward band-structure DFT calculations using the revPBE-D3(BJ) functional have given an (MOH) value of 161.4 kJ/mol on the Au(111) surface, being indicative of significant molecule-surface interaction. The MOH-gold surface binding is shown to take place via the oxygen atom of the hydroxide, with the oxygen-gold charge density transfer increasing from InOH to NhOH. The trend in (MOH) is shown to be InOH < TlOH < NhOH, caused by increasing molecular dipole moments and decreasing stability of the hydroxides in this row. A trend in of the atoms of these elements on gold is, however, opposite, In > Tl > Nh, caused by the increasing relativistic contraction and stabilization of the np AO with . These opposite trends in (MOH) and (M) in group 13 lead to almost equal (Nh) and (NhOH) values, making identification of Nh, as a type of species, difficult by measuring its adsorption enthalpy on gold.
利用分子和周期性相对论密度泛函理论(DFT)计算,预测了铟(In)、铊(Tl)以及超重元素Nh的气态氢氧化物在聚四氟乙烯和金表面的吸附能。这项工作的目的是协助进行与NhOH挥发性相关的“一次一个原子”气相色谱实验。在聚四氟乙烯上获得的(MOH)(其中M = In、Tl、Nh)较低值应能确保分子通过聚四氟乙烯毛细管从加速器轻松传输至化学装置。使用revPBE - D3(BJ)泛函进行的直接能带结构DFT计算得出,在Au(111)表面上(MOH)值为161.4 kJ/mol,这表明分子与表面存在显著相互作用。结果表明,MOH与金表面的结合是通过氢氧化物的氧原子发生的,从InOH到NhOH,氧 - 金电荷密度转移增加。(MOH)的趋势为InOH < TlOH < NhOH,这是由于该行中分子偶极矩增加以及氢氧化物稳定性降低所致。然而,这些元素的原子在金表面上的(某一性质,原文未明确指出)趋势相反,即In > Tl > Nh,这是由np原子轨道随着(某一因素,原文未明确指出)的相对论收缩和稳定性增加所导致的。第13族中(MOH)和(某一性质,原文未明确指出)的这些相反趋势导致(Nh)和(NhOH)值几乎相等,使得通过测量Nh在金上的吸附焓来鉴定Nh作为一种物种变得困难。