The complexation of Cm(III) and Eu(III) with the novel i-SANEX complexing agent 2,6-bis[1-(propan-1-ol)-1,2,3-triazol-4-yl]pyridine (PTD) was studied by time-resolved laser fluorescence spectroscopy (TRLFS). The formation of 1:3, 1:2, and 1:1 metal/ligand complexes was identified upon increasing PTD concentration in 10-3 mol/L HClO4 and in 0.44 mol/L HNO3 solutions. For all these complexes, stability constants were determined at different acid concentrations. Though under the extraction conditions proposed for an An/Ln separation process, that is, for 0.08 mol/L PTD in 0.44 mol/L HNO3, 1:3 complexes represent the major species, a significant fraction of 1:2 complexes was found. This is caused by ligand protonation, and results in lower Eu(III)/Am(III) separation factors compared to SO3-Ph-BTP, until now considered the i-SANEX reference ligand. Focused extraction studies performed at lower proton concentration, where the 1:3 complex is formed exclusively, confirm this assumption.

Time-Resolved Laser Fluorescence Spectroscopy Study of the Coordination Chemistry of a Hydrophilic CHON [1,2,3-Triazol-4-yl]pyridine Ligand with Cm(III) and Eu(III)

MOSSINI, EROS;MACERATA, ELENA;MARIANI, MARIO;
2017

Abstract

The complexation of Cm(III) and Eu(III) with the novel i-SANEX complexing agent 2,6-bis[1-(propan-1-ol)-1,2,3-triazol-4-yl]pyridine (PTD) was studied by time-resolved laser fluorescence spectroscopy (TRLFS). The formation of 1:3, 1:2, and 1:1 metal/ligand complexes was identified upon increasing PTD concentration in 10-3 mol/L HClO4 and in 0.44 mol/L HNO3 solutions. For all these complexes, stability constants were determined at different acid concentrations. Though under the extraction conditions proposed for an An/Ln separation process, that is, for 0.08 mol/L PTD in 0.44 mol/L HNO3, 1:3 complexes represent the major species, a significant fraction of 1:2 complexes was found. This is caused by ligand protonation, and results in lower Eu(III)/Am(III) separation factors compared to SO3-Ph-BTP, until now considered the i-SANEX reference ligand. Focused extraction studies performed at lower proton concentration, where the 1:3 complex is formed exclusively, confirm this assumption.
NITROGEN-DONOR LIGANDS, EURO-GANEX PROCESS, SOLVENT-EXTRACTION, PUREX RAFFINATE, NITRIC-ACID, COMPLEXATION, SEPARATION, ACTINIDES, TRLFS, 2,6-BIS(1,2,4-TRIAZIN-3-YL)-PYRIDINE
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11311/1023318
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