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The development of liquid-liquid separation processes for the effective removal of minor actinide Am(III) from used nuclear fuel (UNF) using ligand-based strategies continues to be an area of significant research focus. The current investigation demonstrates the efficacy of a nitrogen-based bis-triazinyl pyridine (BTP) derivative to selectively extract Am(III) from nitric acid solutions containing light lanthanides. The performance of 3,3ʹ-dimethoxy-phenyl-bis-1,2,4-triazinyl-2,6-pyridine (MOB-BTP) was compared to that of a camphor-substituted BTP (CA-BTP). The results of this investigation demonstrate the novel 3,3ʹ-methoxy-BTP extractant dissolved in a polar diluent was a more efficient extractant for Am(III) at a lower concentration than CA-BTP under comparable conditions. [ABSTRACT FROM AUTHOR]

The development of materials for efficient chemoselective extraction of minor actinides remains at the forefront of research efforts in the area of separation science. Lewis basic complexants derived from nitrogen-donor scaffolds are often employed in this area due to favorable with the transuranic element americium. In the present work an efficient procedure for the preparation of eight useful 3-pyridin-2-yl-1,2,4-triazines (2 novel) is demonstrated via telescoped condensation with the requisite 1,2-dicarbonyl in two-pots without additives, differentially extractive work-up procedures, or recrystallization. Additional efforts in this area have demonstrated the utility of polar aprotic solvents for the preparation of nine functionalized pyridinyl-2,6- bis-1,2,4-triazines (4 novel) directly from the requisite 2,6-pyridine dicarbonitrile in 49-99% yield over four total steps. The streamlined preparation of these important materials and detailed synthetic procedures is reported herein. [ABSTRACT FROM AUTHOR]

Efficient separation of minor actinides from spent nuclear fuel remains a formidable challenge. As part of ongoing efforts to identify effective ligands for separation of toxic radionuclides, a series of bis-1,2,4-triazines, three novel, have been prepared from [1,10]-phenanthroline-2,9-dicarbonitrile in two-telescoped steps without additives, complicated workups, prolonged reaction times, or additional purification. [ABSTRACT FROM AUTHOR]

Among the different components present in spent nuclear fuel, long-lived trivalent actinides are particularly difficult to separate from the shorter-lived lanthanide fission products due to their similar chemical properties. Selective extraction of americium from acidic solution (up to 2M HNO3) containing tenth molar quantities of lanthanides has been achieved using neutral pyridine-based ligands dissolved in polar diluents. Nitrogen-based Bis Triazinyl Pyridine (BTP) ligands are desirable for both their excellent An/Ln selectivity and incinerability. Results pertaining to ligand solubility, kinetics, hydrolytic stability, and extraction performance in various nitric acid environments are presented. [ABSTRACT FROM AUTHOR]