Investigation of f-Element Interactions with Functionalized Diamides of Phenanthroline-Based Ligands

First 4,7-oxygenated 1,10-phenanthroline-2,9-diamides: synthesis, tautomerism and complexation with REE nitrates

“…When 2.0 equiv. of Nd(NO 3 ) 3 are added, the chemical shifts of Phen-H 3,8 and Phen-H 5,6 protons actually overlap. Further addition of neodymium trinitrate results in an interconversion of chemical shifts of these protons of the phenanthroline core.…”

“…For instance, adjusting the geometry of the coordination cavity of ligands and introduction of substituents in the ligand may drastically affect the effectiveness of solvent extraction of f-elements from spent nuclear fuel. [5][6][7] Special attention should be paid to the diamides of 1,10-phe-nanthroline 2,9-dicarboxylic acid (DAPhen, Fig. 1), N,O-donor hybrid ligands' practical value and the advantages of their application in the solvent extraction processes are well documented.…”

New asymmetric tetradentate phenanthroline chelators with pyrazole and amide groups for complexation and solvent extraction of Ln(iii)/Am(iii)

“…The ligands with a 1,10-phenanthroline core have received much attention with respect to An 3+ selectivity over Ln 3+ , 30–40 because the two preorganized nitrogen atoms on the same plane benefit the complexation from the perspective of binding energy. In this context, many symmetric ligands with different functional groups, such as DAPhens (2,9-diamide-1,10-phenanthrolines), 33,41–43 POPhens ((1,10-phenanthroline-2,9-diyl)bis(phosphonate)) 32,36 and BPPhens, 13 have been synthesized for An 3+ selective extraction.…”

Enhancing the Selectivity of Trivalent Actinide over Lanthanide Using Asymmetrical Phenanthroline Diamide Ligands

“…A novel class of phenanthroline diamide ligands (DAPhen) with hard–soft donors has received increasing attention. − The ligand 1,10-phenanthroline-2,9-dicarboxamide (Figure a) was reported to have low affinity to proton and high affinity to f-elements, proving the structural advantages of the amide group and the phenanthroline skeleton in the separation of actinides and lanthanides. , The Am­(III) extraction ability of phenanthroline diamide ligands with different alkyl substitutes was subsequently tested, such as tetrabutyl-1,10-phenanthroline-2,9-dicarboxamide, 2,9-bis­( N , N -dioctylaminocarbonyl)-1,10-phenanthroline (Oct-Oct-DAPhen), and tetradodecyl-1,10-phenanthroline-2,9-diamide (Figure a). The extraction ability of the ligands bearing a longer alkyl chain is weaker because of the stronger steric effect, but their solubility is generally better in more industrially applicable diluents such as kerosene and lipophilic alcohols.…”