Managing Tight Binding Receptors for New Separations Technologies

This program is directed at establishing the fundamental principles that will make the most strongly binding ligands and their complexes available to separations technologies.The ultimate powerful ligands can capture metal ions in the most competitive of circumstances. Ultra tight-binding ligands can remove metal ions from mineralized sites, take them away from lesser ligands, and even capture metal ions from extremely dilute solutions. Further, these feats offer the possibility of solving some of the most serious environmental challenges that cannot be met by existing technologies: decontamination of metal surfaces, removal of metal contaminations from soils, separation of very low concentrations of radioactive metal ions from nuclear waste, capturing of contaminating metal ions from extremely dilute solutions. Despite their promise, extremely stable complexes are rarely used in separations because their great stabilities are accompanied by very slow rates of complex formation and dissociation. Specifically, this program has attacked this limitation in two ways: (1) seeking ba sic scientific ways of overcoming the natural molecular lethargy of ultra tight-binding ligands and (2) developing a new technology that functions despite the slowness of the metal binding reactions. The three basic concept areas of this program are: replace slow equilibrium formation and dissociation of ultra tight-binding complexes by (1) switch-binding of templating ligands, and (2) switch-release of photo reactive ligands, and (3) Create a slow separations technology based on imprinted polymers (e.g., a soil poultice)