A Computational Approach to Predicting Ligand Selectivity for the Size‐Based Separation of Trivalent Lanthanides

Reprocessing of high‐level waste is a key step in advancing sustainable energy systems. The development of efficient chelating agents for trivalent f‐block metal ions is essential for increasing the efficiency of nuclear‐waste remediation and extractive hydrometallurgy of rare‐earth elements. Although computer‐aided screening could lead to a more rapid discovery of superior ligands, an accurate theoretical description of the solvation effects for trivalent metal ions is currently a stumbling block in qualitative predictions for selectivity trends along the lanthanide series. In this work, we propose a robust model to describe the differential effect of solvation in the competitive binding of a ligand with lanthanides by including weakly coordinated counterions in the complexes of more than a +1 charge. The success of this approach in quantitatively reproducing aqueous selectivities demonstrates its potential for the design and screening of new ligands for efficient size‐based separation.