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Lookup NU author(s): Dr Andrey Zaytsev, Rachel Bulmer, Dr Paul Waddell
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. The synthesis and evaluation of three novel bis-1,2,4-triazine ligands containing five-membered aliphatic rings are reported. Compared to the more hydrophobic ligands 1–3 containing six-membered aliphatic rings, the distribution ratios for relevant f-block metal ions were approximately one order of magnitude lower in each case. Ligand 10 showed an efficient, selective and rapid separation of AmIII and CmIII from nitric acid. The speciation of the ligands with trivalent f-block metal ions was probed using NMR titrations and competition experiments, time-resolved laser fluorescence spectroscopy and X-ray crystallography. While the tetradentate ligands 8 and 10 formed LnIII complexes of the same stoichiometry as their more hydrophobic analogues 2 and 3, significant differences in speciation were observed between the two classes of ligand, with a lower percentage of the extracted 1:2 complexes being formed for ligands 8 and 10. The structures of the solid state 1:1 and 1:2 complexes formed by 8 and 10 with YIII, LuIII and PrIII are very similar to those formed by 2 and 3 with LnIII. Ligand 10 forms CmIII and EuIII 1:2 complexes that are thermodynamically less stable than those formed by ligand 3, suggesting that less hydrophobic ligands form less stable AnIII complexes. Thus, it has been shown for the first time how tuning the cyclic aliphatic part of these ligands leads to subtle changes in their metal ion speciation, complex stability and metal extraction affinity.
Author(s): Zaytsev AV, Bulmer R, Kozhevnikov VN, Sims M, Modolo G, Wilden A, Waddell PG, Geist A, Panak PJ, Wessling P, Lewis FW
Publication type: Article
Publication status: Published
Journal: Chemistry - A European Journal
Year: 2020
Volume: 26
Issue: 2
Pages: 428-437
Print publication date: 07/01/2020
Online publication date: 05/09/2019
Acceptance date: 12/08/2019
Date deposited: 18/11/2019
ISSN (print): 0947-6539
ISSN (electronic): 1521-3765
Publisher: Wiley-VCH Verlag
URL: https://doi.org/10.1002/chem.201903685
DOI: 10.1002/chem.201903685
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