Speaker
Description
We report two new hydrophilic phenanthroline-based ligands developed for the separation of actinides from lanthanides in the i-SANEX process: one of bistriazolyl-phenanthroline (BTrzPhen) type incorporating sulfonated hydrophilic groups, and another of phenanthroline-dicarboxamide type named AE-DAPhen. Both ligands exhibit high solubility in aqueous nitric acid solutions. Among them, DSC-BTrzPhen, achieved an excellent separation factor (SFEu/Am) exceeding 440. This represents the highest recorded value for any BTrzPhen ligand. Another ligand, AE-DAPhen, demonstrated a maximum separation factor (SFEu/Am) of 325. Furthermore, solvent extraction tests conducted with Cm(III) indicated SFEu/Cm being 50 for AE-DAPhen, yielding a relative separation factor (SFCm/Am) of 7.4, although recent results obtained by a different approach are placing that value at around 4.5-5, which is still an excellent result. Coordination studies, fluorescence spectroscopy, and theoretical and computational investigations have further revealed the characteristics of these two ligands and helped elucidate their possible mechanisms.