This award provides continuing support for the study of selective binding of oxo metal cations by Dr. Kenneth N. Raymond of the Department of Chemistry, University of California, Berkeley. Shape selective ligands for cations such as osmyl and vanadyl will be developed. These ligands will be designed to stabilize the high oxidation state metal center through normal coordinate binding, while at the same time incorporating hydrogen bond donors for interaction with the oxo cation. Preliminary results show that the hydrogen bonding interaction can be significant if carefully oriented, rigid ligands can be developed. Ligands to be investigated include aminocarboxylates, catechol amides, catechol phenols and amidates. The resulting compounds will be characterized by crystal structure analysis, vibrational spectroscopy, electrochemistry, and solution thermodynamics studies. Both the specificity and complexing ability of the ligands will be tested. %%% The goal of this project is to develop effective and selective agents for scavenging metal oxo cations. A new approach involving the positioning of hydrogen atoms on the complexing agent in such a way as to bind to the oxo group associated with the metal will be tried. The research has implications for separation methodology, including that for members of the lanthanide and actinide families which are found in radioactive waste.
