Evidence for the Perchlorate Anion Coordination in the Structure of Uranyl Cation Complex with N,O-Donor Ligands in a Solution: RMC-EXAFS Study

Complexing of organic ligands with actinides plays a key role in the processes of spent nuclear fuel reprocessing in the final stages of the nuclear fuel cycle. N,O-Donor ligands based on phenanthroline diamides are promising for group isolation and separation of actinides in hydrometallurgical approaches that are alternative to the PUREX process (such as the GANEX process). Understanding of the specific features of actinide ions complexing in an organic solvent may explain the mechanisms of extraction and be useful to find an “ideal” extractant for uranium extraction. Specific features of metal coordination in the presence of perchlorate anion have been studied by the example of a UO 2 (ClO 4 ) 2 complex with pyrrolidine-substituted 1,10-phenanthroline-diamide in an organic solvent, and the structure of the complex compound has been compared with that for a similar compound with nitrate anion as a counter ion.