Evaluation of Multidentate Ligands Derived from Ethyl 1,2,4‐triazine‐3‐carboxylate Building Blocks as Potential An(III)‐Selective Extractants for Nuclear Reprocessing

• DOI: 10.1002/open.202400306
• Publication Date: 2024-11-27T06:04:24Z
• Authors: Andrey V. Zaytsev; Petr Distler; Jan John; Andreas Wilden; Giuseppe Modolo; Mark Sims; Frank W. Lewis
• Keywords: Triazine; Carboxylate; Uranyl

Abstract Bis‐1,2,4‐triazine ligands are amongst the most promising soft N ‐donor for partitioning of trivalent actinides from lanthanides; a key separation proposed in future reprocessing spent nuclear fuels. In an effort to improve extraction properties these benchmark ligands, we propose herein general ligand design approach that is inspired by field drug discovery, and apply it new class which bidentate 3‐(2‐pyridyl)‐1,2,4‐triazine unit replaced 1,2,4‐triazine‐3‐carboxamide unit. A series nine novel were synthesized reactions readily available ethyl 1,2,4‐triazine‐3‐carboxylate building blocks with different polyamine cores evaluated their ability extract separate Am(III) Cm(III) Eu(III). One reported can co‐extract Eu(III) nitric acid into cyclohexanone, albeit no selectivity between metal ions. NMR titration experiments suggested 23 b formed chiral 1 : complex species La(III) but not Lu(III) or Y(III), suggesting coordination cavity sensitive size ion. The structures thermodynamic parameters complexes further supported DFT calculations.