Americium(iii) and europium(iii) solvent extraction studies of amide-substituted triazine ligands and complexes formed with ytterbium(iii)

Abstract

4-Amino-bis(2,6-(2-pyridyl))-1,3,5-triazine L 4 and several, amide derivatives with hydrophobic alkyl substituents have been synthesised. Solvent extraction studies carried out on Am() and Eu() with L 4 and its amide derivatives in synergistic combination with α-bromodecanoic acid, show that these ligands can selectively extract actinides with respect to lanthanides. The structures of [H 2 L 4 ]ؒ2Clؒ2.5H 2 O and two amide derivatives have been determined and show respectively the trans, trans; cis, cis; and cis, trans conformations of the adjacent aromatic rings. These observed conformations are in agreement with the results of quantum mechanics calculations on L 4 and its protonated derivatives. The structures of two Yb complexes with amide derivatives are also reported with stoichiometry [Yb(L)(NO 3 )(H 2 O) 4 ]ؒ2NO 3 ؒ0.5H 2 O and [Yb(L)(NO 3 ) 3 (H 2 O)]ؒ2MeCN and show the metal in 9 coordinate environments.

Development of highly selective compounds for solvent extraction processes: partitioning and transmutation of long-lived radionuclides from spent nuclear fuels

“…• terpyridines (Drew et al, 2000a); • monopyridyl-1,2,4-triazines (Hudson et al, 2003a) and dipyridyl-1,2,4-triazines (Boubals et al, 2002, Hudson et al, 2003a; • dipyridyl-1,3,5-triazines (Drew et al, 2000b) and tripyridyl-1,3,5-triazines (Chan et al, 1996, Hagström et al, 1999; • dioxa-/benzoxa-/binzimida-/zol-pyridines (Kolarik and Müllich, 1997, Andersson et al, 2003, Weigl et al, 2003, Drew et al, 2004b; • amino-dipyridyl-1,3,5-triazines (ADPTZ).…”

The Development of Molecules for the Highly Efficient Separation of Americium(III) from Lanthanides(III)

“…16a Once again, however, the ligands were incapable of extracting the metals from the solutions more acidic than 0.1 M HNO 3 . 18 After a progress flow sheet had been designed, the most promising ligand 13 was employed in a 32-stage spiked test in laboratoryscale mixer settlers at the Commissariat d'Energie Atomique (CEA), with good results (>99.9% Am(III) and Cm(III) recovered and separated from the lanthanides), 15 although the need to buffer the feed solution with glycolic acid/sodium glycolate was an obvious disadvantage. Although ADPTZ 9 and its amido-functionalized derivatives 10-13 efficiently extracted Am(III) from dilute nitric acid solutions in synergistic combination with 2-bromodecanoic acid, the extraction decreased at higher (>0.1 M HNO 3 ) acidities.…”

1,10‐Phenanthroline and Non‐Symmetrical 1,3,5‐Triazine Dipicolinamide‐Based Ligands For Group Actinide Extraction

“…Although only a few limitations were expected in the preparation of 2,9-di(6-picolin-2-yl)-phenanthroline derivatives, the synthesis of 2-substituted-4,6-di(6-picolin-2-yl)-1,3,5-triazines was far from obvious due to the limited sets of methods describing the synthesis of non-symmetrical 2,4,6-substituted derivatives in the literature. [12] Phenanthroline-based extractants First, four new dipicolinamide phenanthroline-based ligands were synthesized following two different routes from commercially available 1,10-phenanthroline 5 (Scheme 1). Route I involves a conventional Stille coupling reaction from 2,9-dichlorophenanthroline 8 obtained in 3 steps according to a literature procedure.…”

“…[17] However, heterocycle sequences containing a non-symmetrically substituted triazine ring have been rarely studied mainly because of the lack of a general efficient method to facilitate their access. [12] Nevertheless, a few derivatives such as 2-amino-, [18] 2-hydroxy-, [18b] and 2-aryl-4,6-di(pyridin-2-yl)-1,3,5-triazine [19] have been described in the literature from a common 2-cyanopyridine precursor and the procedures used were logically evaluated to reach targeted 2-substituted-4,6-di(6-picolin-2-yl)-1,3,5-triazine derivatives 15 a-g from the 2-cyano-6-picoline precursor (Scheme 2). As expected, Route III successfully afforded the 2-phenyl-triazine derivative 15 a (R = Ph) in 82 % yield, by treating 2-cyano-picoline 16 (2 equivalents) with the lithium amidine salt of benzonitrile 14, generated in situ from benzonitrile and lithium dimethylamine (2 m in THF) in Et 2 O.…”