The clusters are assembled through steric and electrostatic forces, with the chloride anions (green spheres) residing in equidistant ‘clefts’ between coordinating diglycolamide ligands in positions that satisfy both repulsive and attractive ion-ion interactions.
Scientific Achievement
Computational modeling in combination with X-ray adsorption spectroscopy showed how sterically-directed electrostatic interactions may assemble stable outer-sphere ion clusters in organic solutions, elucidating new strategies for separations
Significance and Impact
This study provided new insights into controlling the weak forces involved in outer-sphere ion clustering in liquid-liquid extraction systems, which underpins important technological processes that rely on ion separation.
Research Details
A remarkably symmetric complex of lanthanides with three oxygen donor atoms of three extractant known as TODGA, N,N,N,N-tetra(n-octyl)diglycolamide, was characterized using a complimentary combination of density functional theory, molecular dynamics simulations, and X-ray adsorption spectroscopy. Complementary clefts between the coordinating ligands provide a habitat for anions, which facilitates the transport of lanthanides into the organic phase and elucidates new strategies for controlling self-assembly and extraction.
