It has been shown that CyMe4-BTPhen-functionalized silica-coated maghemite (γ-Fe2O3) magnetic nanoparticles (MNPs) are capable of quantitative separation of Am(III) from Eu(III) from HNO3 solutions. These MNPs also show a small but significant selectivity for Am(III) over Cm(III) with a separation factor of around 2 in 4 M HNO3. The water molecule in the cavity of the BTPhen may also play an important part in the selectivity.

Tetrasulfonated bis-1,2,4-triazine ligands can selectively complex and separate actinides from lanthanides in aqueous nitric acid with very high selectivities.

Northumbria University has developed Northumbria Research Link (NRL) to enable users to access the University's research output. Copyright © and moral rights for items on NRL are retained by the individual author(s) and/or other copyright owners. Single copies of full items can be reproduced, displayed or performed, and given to third parties in any format or medium for personal research or study, educational, or not-for-profit purposes without prior permission or charge, provided the authors, title and full bibliographic details are given, as well as a hyperlink and/or URL to the original metadata page. The content must not be changed in any way. Full items must not be sold commercially in any format or medium without formal permission of the copyright holder. The full policy is available online: http://nrl.northumbria.ac.uk/policies.html This document may differ from the final, published version of the research and has been made available online in accordance with publisher policies. To read and/or cite from the published version of the research, please visit the publisher's website (a subscription may be required.) Karel Stamberg, [b] Ana Núñez, [c] Hitos Galán [c] and Amparo G. Espartero [c] Keywords: Ligands / Actinides / Lanthanides / Nuclear waste / Extraction Submitted to the European Journal of Organic ChemistryFour new 6,6'-bis(1,2,4-triazin-3-yl)-2,2'-bipyridine (BTBP) ligands containing either additional alkyl groups on the pyridine rings, or 7-membered aliphatic rings attached to the triazine rings, have been synthesized, and the effects of additional alkyl substitution in the 4-and 4'-positions of the pyridine rings on their extraction properties with Ln(III) and An(III) cations in simulated nuclear waste solutions were studied. The speciation of ligand 13 with some trivalent lanthanide nitrates was elucidated by 1 H NMR titrations and electrospray-ionization mass spectrometry. Whereas ligand 13 formed both 1:1 and 1:2 complexes with La(III) and Y(III), only 1:2 complexes were observed with Eu(III) and Ce(III).Quite unexpectedly, both alkyl-substituted ligands 12 and 13 showed lower solubilities in certain diluents than the nonsubstituted ligand CyMe 4 -BTBP. Compared to CyMe 4 -BTBP, alkyl-substitution was found to decrease the rates of metal ion extraction of the BTBPs in both 1-octanol and cyclohexanone. A highly efficient (D Am > 10) and selective (SF Am/Eu > 90) extraction was observed for BTBPs 12 and 13 in cyclohexanone, and for BTBP 13 in 1-octanol in the presence of a phase-transfer agent. The implications of these results for the design of improved extractants for radioactive waste treatment are discussed. IntroductionOne of the major goals in the treatment of nuclear waste arising from the PUREX process is the selective removal of the radiotoxic minor actinides (Am and Cm) from the lanthanides in a solvent extraction process, known as the SANEX process.[1] Once removed, the oxides of these elements may be converted by high-energy neutrons (transmutation) into less radiotoxic or no...