Development of CMPO-Based Ligands for Selective Lanthanide Extraction

摘要

The wide range of modern applications of the lanthanides has driven a resurgence in research devoted to the selective binding and extraction of these valuable metals. Given recent concerns related to the lanthanide supply chain, coupled with a growing interest in recycling Ln metals from consumer products (cell phones, batteries, etc.),1 development of efficient, scalable technologies to accomplish selective extraction remains worthwhile. As a contribution to this field, our group has been studying multipodal ligands possessing carbamoylmethylphosphine oxide (CMPO), a chelating group well-known in the areas of f-element coordination and liquid-liquid extraction. In generating tripodal CMPO-based ligands, we have seen promising actinide and lanthanide extraction selectivity as a function of ligand capping architecture.23 The focus of this presentation will be on the further development of a tris-(2-aminoethyl)amine (TREN) capped CMPO ligand, TREN-CMPO-OEt (1, Figure 1), as well as variation of extraction conditions to further probe the unique terbium(III) selectivity observed previously.