The utilization of <i>f</i>-elements is increasing with the dependency on materials that are necessary for high-tech and alternative energy applications. While technology continues to develop, an important facet of inorganic chemical research is uncovering new methods for extraction and separation of the rare earth elements (REEs). Obtaining REEs is challenging due to mining processes that are lengthy and generate large amounts of waste. Developing improved lanthanide (Ln) extraction methods would promote efficient isolation of pure metals from natural resources and discarded electronic waste. This presentation details the extraction of Lns from aqueous solution upon varying the ligand scaffold within a tripodal, phenyl substituted ligand with three carbamoylmethylphosphine oxide (CMPO) chelating groups. The comparative study focuses on tris(2-aminoethyl)amine (TREN), tris(3-aminopropyl)amine (TRPN), and a new smaller, more rigid ligand capping structure to tether the CMPO groups. The new ligand structure creates a smaller binding cavity for the extraction of relatively small Lns. Initial liquid-liquid extraction studies with this new ligand revealed solubility issues in the organic solvent used for extraction experiments. This observation led to the use of a more polar solvent than used previously for our standard extraction protocol in hopes of promoting higher solubility of the extracted complex within the organic phase. The effects of this solvent change and smaller capping structure will be presented within the context of extraction results of ligands studied previously. Luminescence studies of select ligand-metal complexes which further explain the coordination environments of these complexes in solution will also be presented.

Effect of scaffold variation of tripodal carbamoylmethylphosphine oxide ligands for lanthanide extraction

ACS Spring 2022

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