Wagner Christoph, Mossini Eros, Macerata Elena, Mariani Mario, Arduini Arturo, Casnati Alessandro, Geist Andreas, Panak Petra J
Universität Heidelberg , Institut für Physikalische Chemie, Im Neuenheimer Feld 253, 69120 Heidelberg, Germany.
Karlsruher Institut für Technologie (KIT) , Institut für Nukleare Entsorgung (INE), P.O. Box 3640, 76021 Karlsruhe, Germany.
Inorg Chem. 2017 Feb 20;56(4):2135-2144. doi: 10.1021/acs.inorgchem.6b02788. Epub 2017 Feb 2.
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 mol/L HClO and in 0.44 mol/L HNO 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 HNO, 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 SO-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.
通过时间分辨激光荧光光谱法（TRLFS）研究了Cm(III)和Eu(III)与新型i-SANEX络合剂2,6-双[1-(丙-1-醇)-1,2,3-三唑-4-基]吡啶（PTD）的络合作用。在10 mol/L HClO和0.44 mol/L HNO溶液中增加PTD浓度时，鉴定出形成了1:3、1:2和1:1的金属/配体络合物。对于所有这些络合物，在不同酸浓度下测定了稳定常数。尽管在所提出的用于锕系/镧系分离过程的萃取条件下，即在0.44 mol/L HNO中0.08 mol/L PTD的条件下，1:3络合物是主要物种，但发现有相当一部分1:2络合物。这是由配体质子化引起的，与迄今为止被视为i-SANEX参考配体的SO-Ph-BTP相比，导致Eu(III)/Am(III)分离因子降低。在较低质子浓度下进行的专门萃取研究（此时仅形成1:3络合物）证实了这一假设。
