Actinide

Hydrogen bond

Lanthanide

Molecular dynamics

Molecule

Outer sphere electron transfer

Catalysis

Metal ions in aqueous solution

Inorganic chemistry

Molecular recognition

Selectivity

Organic chemistry

Chemical physics

Coordination sphere

Computational chemistry

Chemistry

Extraction (chemistry)

ACS Central Science

Fundamental understanding of the selective recognition and separation of f-block metal ions by chelating agents is of crucial importance for advancing sustainable energy systems. Current investigations in this area are mostly focused on the study of inner-sphere interactions between metal ions and donor groups of ligands, while the effects on the selectivity resulting from molecular interactions in the outer-sphere region have been largely overlooked. Herein, we explore the fundamental origins of the selectivity of the solvating extractant N,N,N',N'-tetraoctyl diglycolamide (TODGA) for adjacent lanthanides in a liquid-liquid extraction system, which is of relevance to nuclear fuel reprocessing and rare-earth refining technologies. Complementary investigations integrating distribution studies, quantum mechanical calculations, and classical molecular dynamics simulations establish a relationship between coextracted water and lanthanide extraction by TODGA across the series, pointing to the importance of the hyd...

Outer-Sphere Water Clusters Tune the Lanthanide Selectivity of Diglycolamides