Density functional modeling of Am3+/Eu3+ selectivity with diethylenetriaminepentaacetic acid and its bisamide chelates. Issue 5 (4th May 2021)

• Record Type: Journal Article
• Authors: Kaneko, Masashi; Sasaki, Yuji; Matsumiya, Masahiko; Nakase, Masahiko; Takeshita, Kenji
• Is Part Of: Journal of nuclear science and technology. Volume 58:Issue 5(2021)
• Page Start: 515
• Page End: 526
• Publication Date: 2021-05-04
• Subjects: P&T strategy -- minor actinides -- coordination chemistry -- density-functional theory calculations -- chemical bonding -- hard and soft acids and bases rule; Nuclear engineering -- Periodicals; Nuclear physics -- Periodicals; Nuclear energy -- Periodicals; 621.4805
• DOI: 10.1080/00223131.2020.1842267
• Languages: English
• ISSNs: 0022-3131

Abstract

ABSTRACT: Density-functional theory calculations were applied to mo lecular structure and complex formation reaction modelings of metal ion complexes with diethylenetriaminepentaacetic acid (DTPA) and its bisamide (DTPABA) chelates to understand the metal ion selectivity between Am 3+ and Eu 3+ . The calculated complexes with DTPA and DTPABA chelates reproduced the coordination geometries of experimental crystal structures. Calculated Gibbs free energies of the complex formation reactions indicated that Am 3+ ion forms higher stable complexes with both chelates than Eu 3+ ion, being consistent with the experimental results. The higher Am 3+ selectivity over Eu 3+ was suggested to originate in the larger bond overlap between Am 3+ 5 f-orbital and N 2s, 2p-orbital. This means that the covalent contribution between the metal ion and donor atoms differentiates the complex formation stabilities, leading to the Am 3+ /Eu 3+ selectivity. We expect that this study contributes to systematize the origin of metal ion selectivity and to accelerate novel ligand exploration.