Equilibrium and kinetic aspects of Am(iii)/Eu(iii) pair extraction by a bipyridine-based N,O-donor ligand in different solvents

Abstract

The separation of Am(III) from Ln(III) is crucial for the efficient management of high-level nuclear waste and the closure of the nuclear fuel cycle. This work investigates the effect of an organic solvent on the extraction parameters in a system employing an N,O-donor ligand. It is demonstrated that increasing the polarity of the organic solvent enhances both the extraction efficiency and selectivity. Computer vision techniques were successfully applied to characterize the extraction kinetics, significantly simplifying data analysis. The rate of Am(III) extraction was found to increase when using a more polar solvent. Molecular dynamics simulations revealed that the anti-conformation of the ligand backbone is maintained in all selected solvents. Furthermore, a cage regime was observed for the ligand in non-polar solvents, while sub-diffusion was noted in polar solvents. The atomistic modeling provides further insight into the molecular-level mechanisms that influence the ligand's metal-binding efficacy.