Significant impact of lanthanide contraction on the structure of the phenanthroline complexes

The structure of La, Nd, Eu and Lu complexes with N,N,N',N'-tetrabutyl-1,10-phenanthroline-2,9-dicarbox- amide ligand was examined using X-ray diffraction analysis. Due to the effect of lanthanide contraction, lutetium forms unique type of complex having the coordination number 9 in contrast to other 10-coordinated lanthanides. © 202

The impact of alicyclic substituents on the extraction ability of new family of 1,10-phenanthroline-2,9-diamides

Development of efficient extractants for the separation of actinides and lanthanides in the technologies of nuclear fuel cycle is one of the most urgent and complex tasks in modern nuclear energetics. New family of 4,7-dichloro-1,10-phenanthroline-2,9-dicarboxylic acid diamides based on cyclic amines was synthesized and shown to exhibit high selectivity in the La/Am pair separation (SF (Am/La ≈ 10)) and in the Am/Eu pair separation (SF (Am/Eu ≈ 12)). It was shown that pyrrolidine derived diamide is more efficient extractant for americium, curium and lanthanides from highly acidic HNO3 solution than its non-cyclic N,N,N′,N′-tetraalkyl analogues. The structures of synthesized compounds were studied in details by IR, NMR spectroscopy, and single crystal X-ray diffraction. According to spectroscopy data, incorporation of aromatic rings to the amide fragment of ligand leads to complex dynamic behavior in solutions what is believed to strongly affect the extraction ability of synthesized ligands. © 2020 The Royal Society of Chemistry