The <i>f</i>-elements are important in many modern applications ranging from advanced computers and smartphones to alternative energy. Given the increasing relevance in high-tech devices, interest in the acquisition of the lanthanide metals in particular, both from mining and product recycling, continues to grow. We have been developing ligands for lanthanide extraction and separations that utilize the carbamoylmethylphosphine oxide (CMPO) metal chelating group. Over the past several years, our group has generated a series of ligands that tether three CMPO units to central capping scaffolds of varying size and composition. This approach has enabled variation of the ligand “cap” as well as CMPO substituents for further tuning of the molecular structure and solubility properties. This presentation will give an overview of the effect of the ligand capping scaffold on metal extraction, highlighting some promising selective lanthanide and actinide extraction results via a standard liquid-liquid protocol. Recent studies have also more closely examined variation of the extraction protocol itself (e.g., varying ligand concentration and mixing times). For example, a surprising result of increased metal extraction upon moving to smaller relative ligand concentrations will be discussed. Finally, the effect of ligand cap variation on thorium(IV) extraction relative to Lns will be presented for a CMPO extractant based on a longer, more flexible alkyl amine cap than those previously studied.

Tuning the <i>f</i>-element extraction properties of tripodal CMPO-based ligands

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.

Tuning the f-element extraction properties of tripodal CMPO-based ligands