Abstract We theoretically investigated the selective back-extraction towards Am(III) over Eu(III) and Cm(III) with two water-soluble 2,9-bis-triazolyl-1,10-phenanthroline derivatives BTrzPhen1 (with two ethanol side chains) and BTrz-Phen2 (with two 1,2-butanediol side chains) by density functional theory (DFT). The molecular geometries and formation reactions of the metal-ligand complexes were modeled by using M(BTrzPhen)(NO3)3 and [M(BTrzPhen)2(NO3)]2+. Am(III) selectivity over Eu(III) and Cm(III) with BTrzPhen2 was successfully reproduced by back-extraction reaction free energy analysis. Moreover, bonding properties between the metal cations and coordinated ligands (model complexes) were studied in terms of Mayer bond order and quantum theory of atoms in molecule (QTAIM). The difference in covalency between An–N and Eu–N bonds were found to be the key factors for Am(III)/Eu(III) separation, while the Am(III) selectivity over Cm(III) of BTrzPhen2 might be attributed to the competition of donor atoms for cation binding preference toward Am(III) and Cm(III).

中文翻译：

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使用两个亲水性 1,10-菲咯啉-2,9-双三唑基配体从 Eu(III) 和 Cm(III) 中选择性反萃取 Am(III) 的量子化学研究

摘要 我们从理论上研究了用两种水溶性 2,9-双-三唑基-1,10-菲咯啉衍生物 BTrzPhen1（具有两个乙醇侧链) 和 BTrz-Phen2（具有两个 1,2-丁二醇侧链）通过密度泛函理论 (DFT)。通过使用 M(BTrzPhen)(NO3)3 和 [M(BTrzPhen)2(NO3)]2+ 对金属-配体配合物的分子几何结构和形成反应进行建模。通过反萃取反应自由能分析成功地再现了使用 BTrzPhen2 对 Eu(III) 和 Cm(III) 的 Am(III) 选择性。此外，根据迈耶键序和分子中原子的量子理论（QTAIM）研究了金属阳离子和配位配体（模型配合物）之间的键合性质。