Synergistic Solvent Extraction of Trivalent Americium and Europium by 2-Bromodecanoic Acid and Neutral Nitrogen-Containing Reagents

Hagström, I.; Spjuth, Lena; Enarsson, Åsa; Liljenzin, Jan‐Olov; Skålberg, Μ.; Hudson, Michael J.; Iveson, Peter B.; Madic, C.; Cordier, P.Y.; Hill, C.; François, N.

doi:10.1080/07366299908934610

Cited by 85 publications

(84 citation statements)

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“…As 30 expected, the extraction of Am(III) improves at low [HNO 3 ] (D Am = 1.3 at 0.001 M HNO 3 ) but the distribution ratios decrease again at higher acidities. The above results demonstrate that replacement of one of the 1,2,4-triazine rings in the BTBP ligands with a pyridine ring leads to a marked decrease in extraction 35 performance and selectivity, and show that two 1,2,4-triazine rings are important for optimum results. A similar effect has previously been observed when one of the 1,2,4-triazine rings of the tridentate BTP ligands was replaced with a pyridine ring.…”

Section: Solvent Extraction Studiesmentioning

confidence: 65%

“…Instead, an averaged NMR spectrum of both species was observed throughout the titration (see Figures 40 and 41 in the Supporting Information). Only one set of resonances was 35 observed (two methyl peaks, one methylene resonance, one set of aromatic peaks), with minor changes in chemical shift occurring in some cases until 1.1 equivalents of metal had been added, after which no further spectroscopic changes were observed. This suggests that a rapid exchange process is taking place faster than 40 the NMR timescale can detect.…”

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confidence: 99%

“…Both 1:1 and 1:2 species are formed, with the 1:2 species being the major species at low metal:ligand ratios. 35 The 1:1 species becomes the only solution species present at high (> 1.2 equivalents Y(III)) metal:ligand ratios. In the aliphatic region, the methyl resonances for the 1:2 complex of 2 appear as four singlets (Figure 10).…”

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confidence: 99%

“…Extensive studies on oligopyridine 55 coordination chemistry 33 by Constable and others have shown that the quaterpyridine ligands typically form planar mononuclear 1:1 complexes with metals that favour square planar or octahedral coordination geometries (eg: Ni(II), Pd(II), Fe(II), Co(II)). 34,35 On the other hand, metals that favour tetrahedral coordination 60 geometries (eg: Cu(I), Ag(I)) usually form dinuclear doublehelical 2:2 complexes, 36 although some rare exceptions have been noted. 37 Non-symmetrical quaterpyridine ligands are of particular interest as they are capable of forming directional isomers (headto-head or head-to-tail isomers) when they form dinuclear 65 double-helicates.…”

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confidence: 99%

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Complexation of lanthanides, actinides and transition metal cations with a 6-(1,2,4-triazin-3-yl)-2,2′:6′,2′′-terpyridine ligand: implications for actinide(iii)/lanthanide(iii) partitioning

et al. 2012

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The quadridentate N-heterocyclic ligand 6- (5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-1,2,4-benzotriazin-3-yl)-2,2′ : 6′,2′′-terpyridine (CyMe 4 -hemi-BTBP) has been synthesized and its interactions with Am(III), U(VI), Ln(III) and some transition metal cations have been evaluated by X-ray crystallographic analysis, Am(III)/Eu(III) solvent extraction experiments, UV absorption spectrophotometry, NMR studies and ESI-MS. Structures of 1 : 1 complexes with Eu(III), Ce(III) and the linear uranyl (UO 2 2+ ) ion were obtained by X-ray crystallographic analysis, and they showed similar coordination behavior to related BTBP complexes. In methanol, the stability constants of the Ln(III) complexes are slightly lower than those of the analogous quadridentate bis-triazine BTBP ligands, while the stability constant for the Yb(III) complex is higher. 1 H NMR titrations and ESI-MS with lanthanide nitrates showed that the ligand forms only 1 : 1 complexes with Eu(III), Ce(III) and Yb(III), while both 1 : 1 and 1 : 2 complexes were formed with La(III) and Y(III) in acetonitrile. A mixture of isomeric chiral 2 : 2 helical complexes was formed with Cu(I), with a slight preference (1.4 : 1) for a single directional isomer. In contrast, a 1 : 1 complex was observed with the larger Ag(I) ion. The ligand was unable to extract Am(III) or Eu(III) from nitric acid solutions into 1-octanol, except in the presence of a synergist at low acidity. The results show that the presence of two outer 1,2,4-triazine rings is required for the efficient extraction and separation of An(III) from Ln(III) by quadridentate N-donor ligands. † Electronic supplementary information (ESI) available: Procedures and characterization data for known compounds, Mercury plot of ligand 2 and its Eu, Ce and U complexes, NMR stack plots and species distribution curves, enlargements of mass peaks for La(III), Eu(III), Cu(I) and Ag(I) complexes of 2. CCDC 869233-869236. For ESI and crystallographic data in CIF or other electronic format see

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Section: Solvent Extraction Studiesmentioning

confidence: 65%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Complexation of lanthanides, actinides and transition metal cations with a 6-(1,2,4-triazin-3-yl)-2,2′:6′,2′′-terpyridine ligand: implications for actinide(iii)/lanthanide(iii) partitioning

et al. 2012

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“…tri-tertio-butyl-pyridyl-triazine, T t BuPTZ), were able to separate An(III) from Ln(III) when mixed with lipophilic anions. [1,2] However, bis-triazinyl-pyridines (BTP, Figure 1), a new family of nitrogen-containing polydendate ligands recently developed by Z. Kolarik et al [3] in the framework of a European contract led by CEA-Marcoule, 1 appeared to be very efficient and selective extracting agents towards An(III), even from very acidic aqueous solutions (e.g. [HNO 3 ] ≥2 mol/L).…”

Section: Introductionmentioning

confidence: 99%

Sanex-Btp Process Development Studies

Hill¹,

Guillaneux

Berthon

et al. 2002

Journal of Nuclear Science and Technology

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Bis-triazinyl-pyridines (BTPs) have been developed at CEA-Marcoule to separate actinides(III) from lanthanides(III). Although high separation performances were observed in the counter-current hot test carried out in 1999 on a highly active effluent, the extraction and back-extraction yields of actinides(III) were lower than expected from calculation. A strong sensitivity of the extractant towards air oxidation and acidic hydrolysis was actually pointed out. Therefore, the hydrolysis of bis-triazinylpyridines was deeply investigated (qualitative determination of the degradation products) in different experimental conditions. It appeared that the branching of the alkyl groups on the α position of the triazine rings hindered the hydrolysis of the extractant. The formulation of the solvent was thus optimised and tested again in 2001 on a genuine DIAMEX back-extraction solution in the ATALANTE facility. 454

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Selective Complexation of Uranium(III) over Cerium(III) and Neodymium(III) by 2,2′:6′,2′′-Terpyridine − X-ray Crystallographic Evidence for Uranium-to-Ligand π Back-Bonding

Berthet

Rivière

Miquel

et al. 2002

Eur. J. Inorg. Chem.

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The addition of 2,2Ј:6Ј,2ЈЈ-terpyridine (terpy) to MI 3 (M = Ce, Nd, U) in anhydrous pyridine led to the quantitative formation of the bis-terpy complexes [MI 2 (terpy) 2 ]I [M = Ce (1) and Nd (2)] and [MI 2 (terpy) 2 L]I [M = U and L = pyridine (3); M = Ce and L = H 2 O ( 4)]. Conductometry measurements indicated that these complexes are 1:1 electrolytes in pyridine solution. 1 H NMR competition experiments showed that the terdentate ligand has a better affinity for U III than for Ce III or Nd III . The X-ray crystal structures of solvates of 1−4 have

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Synergistic Solvent Extraction of Trivalent Americium and Europium by 2-Bromodecanoic Acid and Neutral Nitrogen-Containing Reagents

Cited by 85 publications

References 12 publications

Complexation of lanthanides, actinides and transition metal cations with a 6-(1,2,4-triazin-3-yl)-2,2′:6′,2′′-terpyridine ligand: implications for actinide(iii)/lanthanide(iii) partitioning

Complexation of lanthanides, actinides and transition metal cations with a 6-(1,2,4-triazin-3-yl)-2,2′:6′,2′′-terpyridine ligand: implications for actinide(iii)/lanthanide(iii) partitioning

Sanex-Btp Process Development Studies

Selective Complexation of Uranium(III) over Cerium(III) and Neodymium(III) by 2,2′:6′,2′′-Terpyridine − X-ray Crystallographic Evidence for Uranium-to-Ligand π Back-Bonding

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