Development of Highly Selective Ligands for Separations of Actinides from Lanthanides in the Nuclear Fuel Cycle

This account summarizes recent work by us and others on the development of ligands for the separation of actinides from lanthanides contained in nuclear waste streams in the context of a future European strategy for nuclear waste management. The current status of actinide/lanthanide separations worldwide is briefly discussed, and the synthesis, development, and testing of different classes of heterocyclic soft N- and S-donor ligands in Europe over the last 20 years is presented. This work has led to the current benchmark ligand that displays many of the desirable qualities for industrial use. The improvement of radiolytic stability through ligand design is also discussed. 1 Introduction and Background 2 Dithiophosphinic Acids 3 2,2': 6',2 ''-Terpyridine (TERPY) and Related Ligands 4 2,4,6-Tri-2-pyridyl-1,3,5-triazine (TPTZ) and Related Ligands 5 2,6-Bis(benzoxazol-2-yl)-4-dodecyloxypyridine (BODO) and Related Ligands 6 Podand Ligands 7 2,6-Bis(1,2,4-triazin-3-yl) pyridine (BTP) and Related Ligands 8 6,6'-Bis(1,2,4-triazin-3-yl)-2,2'-bipyridine (BTBP) and Related Ligands 9 Improving Radiolytic Stability through Ligand Design 10 Conclusion and Outlook