Seawater uranium sequestration has seen a significant increase in research interest due to the projected depletion of terrestrial ores within our lifetime. Seawater contains roughly 4.5 billion tons of uranium, a thousand times the known terrestrial reserves, making it an essential and extensive source of raw material for decades to come. A significant stumbling block to seawater sequestration has been the separation processes of uranium from the complexation agent which involves concentrated acid baths. The baths rapidly degrade the media reducing the duty cycle and increases the processing cost to impractical levels.  Initial findings suggest that the addition of an aromatic sub structure (�backbone�) can increase the durability of the ligands during processing. For this reason, we have chosen a molecule with a significant aromatic �backbone� for which we have designed a synthetic route and produced pilot quantities for study. This compound was characterized natively and complexed with uranium by nuclear magnetic resonance spectroscopy (NMR), mass spectroscopy (MS), elemental analysis, x-ray crystallography, infrared spectroscopy (IR) and Raman spectroscopy. Further understanding of the system's electronic character and predictions of the uranyl stretching frequency have been gathered from density functional theory (DFT) studies.  Our ligand readily binds with uranium as have previous compounds, however our molecule exhibits a 1:1 binding motif verses the previously encountered 2:1 ligand : uranium binding. This is a beneficial development that should theoretically cut the number of binding sites required by half and doubling the amount of uranium captured per cycle. The improved binding ratio demonstrated by this new molecule represents a significant improvement upon previous uranium binders of this functional group. In addition the expected enhanced resistance to hydrolysis of this ligand stands to make it a significant advancement in uranium capture.

Synthesis and characterization of a new ligand for uranium capture

247th National Meeting (2014)

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