Title

Isolation of the Uranyl Dication

Presentation Type

Poster

Abstract

This project focuses on the isolation of uranium, in the form the uranyl dication (UO22+), from aqueous solutions. Humanity needs new sources of energy, and a known and efficient way to create energy is by a closed nuclear fuel cycle using the element uranium. Uranium exists in various forms on earth, but aqueous uranium exists almost exclusively as the uranyl ion. The uranyl ion exists in abundance in dilute form in seawater (3 ppb), but is difficult to selectively extract from such a cation-filled ocean and an efficient method of collecting it has not been studied in detail. Also, the uranyl ion has unusual geometry making it difficult to isolate (it is a linear molecule due to two double bonded oxygens, thus is restricted to planar coordination about its equator). The purpose of this project is to combine different ligand building blocks with the uranyl ion and allow them to self-assemble around the dication. The ligands will encapsulate the ion, allowing it to be isolated. Because the ligands self-assemble without adding energy to the system, the most thermodynamically favorable structure will emerge. These self-assembly reactions are known as dynamic combinatorial chemistry (DCC). Solutions of various ligands will be reacted to elucidate the most stable ligand complexes. This project focuses on using ligands with thiol functionality which participate in disulfide bond exchange. The effectiveness, stability, and structure of the resulting ligand complexes will be analyzed by both Nuclear Magnetic Resonance, NMR, and by High Performance Liquid Chromatography, HPLC. Once robust thermodynamically stable structures have been self-assembled, future work will involve synthesizing a favorable ligand complex using non-dynamic chemistry and attaching it to a scaffold for sea water extraction.

Category

Physical Sciences

This document is currently not available here.

Share

COinS
 
Apr 11th, 3:00 PM Apr 11th, 4:00 PM

Isolation of the Uranyl Dication

This project focuses on the isolation of uranium, in the form the uranyl dication (UO22+), from aqueous solutions. Humanity needs new sources of energy, and a known and efficient way to create energy is by a closed nuclear fuel cycle using the element uranium. Uranium exists in various forms on earth, but aqueous uranium exists almost exclusively as the uranyl ion. The uranyl ion exists in abundance in dilute form in seawater (3 ppb), but is difficult to selectively extract from such a cation-filled ocean and an efficient method of collecting it has not been studied in detail. Also, the uranyl ion has unusual geometry making it difficult to isolate (it is a linear molecule due to two double bonded oxygens, thus is restricted to planar coordination about its equator). The purpose of this project is to combine different ligand building blocks with the uranyl ion and allow them to self-assemble around the dication. The ligands will encapsulate the ion, allowing it to be isolated. Because the ligands self-assemble without adding energy to the system, the most thermodynamically favorable structure will emerge. These self-assembly reactions are known as dynamic combinatorial chemistry (DCC). Solutions of various ligands will be reacted to elucidate the most stable ligand complexes. This project focuses on using ligands with thiol functionality which participate in disulfide bond exchange. The effectiveness, stability, and structure of the resulting ligand complexes will be analyzed by both Nuclear Magnetic Resonance, NMR, and by High Performance Liquid Chromatography, HPLC. Once robust thermodynamically stable structures have been self-assembled, future work will involve synthesizing a favorable ligand complex using non-dynamic chemistry and attaching it to a scaffold for sea water extraction.