Separation of Am (III) by solvent extraction using water-soluble H4tpaen derivatives

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

“…[18,19] This novel sulfonated ligand allowed to obtain Cm/Am separation factors of 3.3 -3.5 at relatively high nitric acid concentrations (0.1 -1 mol L -1 ) with fast kinetics, but the organic synthesis of the ligand seems less reproducible than the lipophilic version of the BTPhen molecule. [18,20,21] As an alternative for the hydrophilic complexant TS-BTPhen, N,N′,N″,N‴-tetrakis[(6-carboxypyridin-2-yl)methyl]ethylenediamine (H4TPAEN) [22][23][24] in combination with TODGA offered highly similar Am/Cm separation factors (3.5 -4.0), but with lower separation factors towards the light lanthanides. TODGA in combination with 2,6bis[1-(propan-1-ol)-1,2,3-triazol-4-yl)]pyridine (PyTri-diol) [25] allowed a separation factor of Cm/Am of only 1.4.…”

Effect of Oxygen-Donor Charge on Adjacent Nitrogen-Donor Interactions in Eu3+ Complexes of Mixed N,O-Donor Ligands Demonstrated on a 10-Fold [Eu(TPAMEN)]3+ Chelate Complex

“…For the synthesis of TPAMEN ( 2 ) two different reaction paths were considered (see Scheme ): ( I ) a direct amide conversion of the carboxyl groups in H 4 TPAEN and ( II ) the construction of the TPEN framework on the basis of a 6-(chloromethyl)-2-pyridine carboxamide derivative, already containing the amide moiety. The starting material H 4 TPAEN ( 1 ) for reaction I was synthesized by a procedure reported by Gracia et al The amide conversion was achieved by chlorination of the carboxylic acid groups in 1 with an excess of SOCl 2 , followed by a subsequent reaction of the acid chloride with diethylamine to give the product 2 . The reaction conditions were chosen on the basis of a procedure by Mariani, Casnati, et al for the amide conversion of monomethyl dipicolinate (see also Scheme S1c in the Supporting Information) .…”

“…H 4 TPAEN is a tetrapodal, decadentate ligand with a 6-fold N-donor framework, based on N,N,N′,N′ -tetrakis­(2-pyridylmethyl)­ethylenediamine (TPEN) (Figure ), extended by four additional carboxylic acid groups. The TPEN framework also renders this ligand as having promise for selective MA separation, which has initiated several studies on its Am 3+ /Eu 3+ and Am 3+ /Cm 3+ selectivity. , Despite its high separation factor for Am 3+ /Eu 3+ , H 4 TPAEN’s poor solubility under acidic conditions limits its application in separation processes and requests further adjustments of the ligand design . The attempts by Gracia et al to increase the solubility of the ligand in aqueous media by introducing polar groups in the para position of the pyridyl ring resulted in the desired higher solubility but also in a loss of Am 3+ /Eu 3+ selectivity …”

Optimizing the Readout of Lanthanide-DOTA Complexes for the Detection of Ligand-Bound Copper(I)

“… Picolinate-derivatized ligands have previously been shown to act as sensitizers for europium and terbium ions [ 32 , 33 , 34 , 35 ], to undergo cellular entry via diffusion, and to be suitable for two photon excitation studies. Thus picolinate azides 6 – 9 were prepared from pyridine-2,6-dicarboxylic acid dimethyl ester through ready adaptation of the synthetic route to the 10-coordinate N , N , N ′, N ′-tetrakis[(6-carboxypyridin-2-yl)methyl]ethylenediamine (tpaen) ligand reported by Mazzanti et al [ 33 , 36 , 37 ] ( SM Scheme S2 ; three steps (28% overall), four steps (15% overall), three steps (27% overall), and four steps (22% overall) respectively). Lanthanide complexes based on coumarin derivatives were pursued due to the known membrane permeability of coumarin azides [ 38 ], and previous reports of strong fluorescence activation of lanthanides by coumarin [ 39 , 40 , 41 , 42 ].…”