High-Performance Alkyl Diamide Amine and Water-soluble Diamide Ligand for Separating of Am(III) from Cm(III)

Abstract

Alkyl diamide amine (ADAAM), a new high-performance reagent with a simple structure, was examined for the mutual separation of Am(III) and Cm(III). The combination of ADAAM and N,N,N′,N′-tetraethyldiglycolamide (TEDGA) as a masking agent shows selectivity for Am(III) over Cm(III) in highly acidic media with separation factors of up to 41.

Selective Extraction of Americium from Curium and the Lanthanides by the Lipophilic Ligand CyMe4BTPhen Dissolved in Aliquat-336 Nitrate Ionic Liquid

“…From an aqueous phase of containing 0.001 mol L -1 TEDGA in 1.5 mol L -1 HNO3 spiked with Am(III) and Cm(III), with 0.75 mol L -1 ADAAM(EH) in n-dodecane SFAm/Cm = 5.7 was achieved (DAm > 1, DCm < 1). [30] The feasibility of the Am(III)/Cm(III) separation was demonstrated on a counter-current mixer settler test, which allowed the recovery of 99.8 % Am(III) with only 9.6 % of Cm(III) impurity in the product. [31] The solvent composed of 0.25 mol L -1 ADAAM(EH) and the feed contained 1.5 mol L -1 HNO3 spiked with Am(III) and Cm(III) without the use of the aqueous complexant, TEDGA.…”

Theoretical Study of Effects of Solvents, Ligands, and Anions on Separation of Trivalent Lanthanides and Actinides

“…In principle, the ligand selectivity can be improved by tuning the ligands. Thus, many experiments and calculations have been dedicated to the search for efficient ligands, such as BTPs, 6,6′-bis­(5,6-dialkyl–1,2,4-triazin-3-yl)-2,2′-bipyridine (BTBPs), 2,9-bis­(1,2,4-triazin-3-yl)-1,10-phenanthroline (BTPhens), 6,6″-bis­(1,2,4-benzotriazin-3-yl)-2,2′:6′,2″-terpyridines (BTTPs), and N , N , N ′, N ′-tetrakis­(2-pyridylmethyl)­ethylenediamine (TPEN) as soft donors ligands. − Among the tested ligands, soft N donors, hard O donors, and mixed ‘N, O’ donors − belong to Lewis bases in terms of hard and soft acids and bases theory (HSAB) . Conversely, trivalent Am and Eu ions pertain to hard Lewis acids with a large ionic radius and relatively positive charge .…”

“…To understand the molecular mechanism of the extraction process, various theoretical studies − ,− ,− have been carried out, characterizing the molecular structure and electronic distribution of Am­(III)/Eu­(III) complexes with different extractive ligands using the natural bond orbital (NBO) or quantum theory of atoms in molecules (QTAIM). It was found that the electrostatic interaction between ligands and metal ions could be regulated by the selection of ligands.…”

Direct Temperature-Swing Extraction of Rare-Earth Elements from Acidic Solution Using the Hydrophobic Interactions of Poly(N-isopropylacrylamide) with Diglycolamide-typed Ligands

“…As DA-typed ligands, 2-ethylhexyl diamide amine (ADAAM(EH)) and ethyl diamide amine (ADAAM(Et)) were used as hydrophobic and hydrophilic ligands, respectively. 13…”