Design, synthesis and evaluation of ditopic polyphenol based hydroxypyridinone extractants for cations

ORGN 416

Aravamudan S. Gopalan, agopalan@nmsu.edu, Jonathan M. Shirley, jshirley@nmsu.edu, and Hollie K. Jacobs, hjacobs@nmsu.edu. Department of Chemistry and Biochemistry, New Mexico State University, MSC 3C, Las Cruces, NM 88003-8001
Our laboratory is exploring a novel class of ditopic ligands systems (L) built on bis- and tris- phenolic platforms that are capable of simultaneously binding an anion and a target metal ion to give neutral complexes (MLX). Such ligands should be efficient extractants of the target cation to organic media from aqueous media if the extracted ditopic complex is neutral. We have synthesized several bis- and tris- hydroxypyridinones (HOPO), in which the HOPO moieties are anchored to the polyphenol platform via a carboxamide or sulfonamide linkage. The corresponding model compounds without the metal binding HOPO ligand or the anion binding sites also have been synthesized to understand the extraction process in these novel extractants. Here we present our synthetic approach to this novel class of extractants and our preliminary anion/cation complexation studies. The impetus for this work comes from our goal to identify selective extractants for actinides from aqueous radioactive waste streams.