ACTINIDE PHOSPHONATE COMPLEXES IN AQUEOUS-SOLUTIONS

Complexes formed by actinides with carboxylic acids, polycarboxylic ac ids, and aminopolycarboxylic acids play a central role in both the bas ic and the process chemistry of the actinides. Recent studies of f ele ment complexes with phosphonic acid ligands indicate that new ligands incorporating doubly ionizable phosphonate groups (-PO3H2) have many p roperties which are unique chemically, and promise more efficient sepa ration processes for waste clean-up and environmental restoration. Sim ple diphosphonate ligands form much stronger complexes than isostructu ral carboxylates, often exhibiting higher solubility as well. In this manuscript recent studies of the thermodynamics and kinetics of f elem ent complexation by 1,1- and 1,2-diphosphonic acid ligands are describ ed.