Novel Soft–Hard Donor Ligand, NTAamide, for Mutual Separation of Trivalent Actinoids and Lanthanoids

Abstract

New reagent, N,N,N′,N′,N′′,N′′-hexaoctylnitrilotriacetamide (NTAamide(C8)), was synthesized and examined for actinoid and lanthanoid extractions. NTAamide(C8) has one N atom and three carbonyl oxygen atoms in the central frame, and may show hybrid bonds between hard O and soft N donors. It was found that NTAamide can extract Am(III) and Cm(III) from diluted HNO3 with small D(Ln). This result suggests that the N-donor makes stronger complexes with Am(III) and Cm(III) than Ln(III) at low HNO3.

Selective extraction of americium(III) over europium(III) ions in nitric acid solution by NTAamide(C8) using a novel water-soluble bisdiglycolamide as a masking agent

“…This also showed better selectivity of TEE-BisDGA than TEDGA toward Eu(III) over Am(III) [17,19]. Meanwhile, SFAm/Eu increased with the increase of NTAamide(C8) concentration, which is also in agreement with that from literatures [7,14]. In addition, all DAm and DEu values of TEE-BisDGA are higher than the counterpart values of TEDGA, meaning that the latter has stronger complexation ability with Am(III) and Eu(III) than the former [19].…”

“…DEu decreased with the increase of HNO3 concentration, which was similar to that reported by Sasaki [7]. When HNO3 concentration exceeds 0.01 mol/L, the downward trend is more obvious.…”

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

“…The separation of these two closely related MAs is even more challenging than that of MA(III) and Ln(III). [3][4][5] Although various ligands and separation methods have been studied for the Am(III)/Cm(III) separation, [6][7][8][9][10][11] an effective approach for practical use has not yet been developed.…”

High selective extraction for thorium(IV) with NTAamide in nitric acid solution: Synthesis, solvent extraction and structure studies

“…amidated NTA, was found to have a good selectivity for trivalent actinides over lanthanides. The separation factor between Am(III) and Eu(III) can be achieved 52.6 in the case of 0.5 M NTAamide(C8) in n-dodecane at 0.2 M HNO 3 [28,29]. In addition, it also has been well established that the stable complexes can be formed between Th(IV) and NTA in aqueous solution, whose stability constants of Th(IV) are much higher than those of U(VI) and Gd(III) [30][31][32].…”