First 24-Membered Macrocyclic 1,10-Phenanthroline-2,9-Diamides-An Efficient Switch from Acidic to Alkaline Extraction of f-Elements

Int J Mol Sci. 2023 Jun 17;24(12):10261. doi: 10.3390/ijms241210261.

Abstract

A reaction of acyl chlorides derived from 1,10-phenanthroline-2,9-dicarboxylic acids with piperazine allows the preparation of the corresponding 24-membered macrocycles in good yield. The structural and spectral properties of these new macrocyclic ligands were thoroughly investigated, revealing promising coordination properties towards f-elements (Am, Eu). It was shown that the prepared ligands can be used for selective extraction of Am(III) from alkaline-carbonate media in presence of Eu(III) with an SFAm/Eu up to 40. Their extraction efficiency is higher than calixarene-type extraction of the Am(III) and Eu(III) pair. Composition of macrocycle-metal complex with Eu(III) was investigated by luminescence and UV-vis spectroscopy. The possibility of such ligands to form complexes of L:Eu = 1:2 stoichiometry is revealed.

Keywords: DFT; NMR; XRD; actinide; lanthanide; macrocycle; phenanthroline; solvent extraction.

MeSH terms

  • Coordination Complexes* / chemistry
  • Diamide*
  • Ligands
  • Models, Molecular

Substances

  • 1,10-phenanthroline
  • Diamide
  • Ligands
  • Coordination Complexes