Remarkable Enhancement in Extraction of Trivalent f-Block Elements Using a Macrocyclic Ligand with Four Diglycolamide Arms: Synthesis, Extraction, and Spectroscopic and Density Functional Theory Studies
Remarkable Enhancement in Extraction of Trivalent f-Block Elements Using a Macrocyclic Ligand with Four Diglycolamide Arms: Synthesis, Extraction, and Spectroscopic and Density Functional Theory Studies
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DOI：
10.1021/acs.inorgchem.9b02605
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发表时间：
2019-11-04
影响因子：
4.6
通讯作者：
Verboom, Willem
中科院分区：
文献类型：
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作者：
Bhattacharyya, Arunasis;Egberink, Richard J. M.;Verboom, Willem
含有多个二甘醇酰胺 (DGA) 的配体，具有连接到 tetraaza-12-crown-4 环的四个 DGA 臂，即。合成了 2,2',2 '',2'"-(((1,4,7,10-四氮杂环十二烷-1,4,7,10-四基)四(2-氧乙烷-2,1-二基)) 四(氧)) 四(N,N-二辛基乙酰胺) (T12C4ODGA)，并评估了不同锕系元素和 镧系离子，即Am3+、Eu3+、Pu4+、Np4+ 和 UO22+。与之前报道的多种基于 DGA 的配体相比，考虑到本研究中使用的配体浓度非常低，本配体的萃取效率是迄今为止报道的最高，更具体地说是三价金属离子 Am3+ 和 Eu3+。配合物的性质 使用时间分辨荧光 (TRFS) 和扩展 X 射线吸收精细结构 (EXAFS) 光谱研究了 Eu3+ 萃取过程中形成的物质。溶剂萃取和 TRFS 研究均表明在 Am3+ 和 Eu3+ 萃取过程中存在 1:1 和 1:2 络合物，1:1 络合物中具有三个内层水分子。密度泛函理论（DFT）研究 对 T12C4ODGA 和具有甲基代替正辛基的类似化合物的 Am3+ 和 Eu3+ 配合物进行了分析，T12C4ODGA 的 DFT 结果很好地解释了 Am3+ 和 Eu3+ 的萃取行为。
A multiple diglycolamide (DGA)-containing ligand having four DGA arms tethered to a tetraaza-12-crown-4 ring, viz. 2,2',2 '',2'"-(((1,4,7,10-tetraazacyclododecane-1,4,7,10-tetrayl)tetrakis(2-oxoethane-2,1-diyl)) tetrakis (oxy)) tetrakis(N,N-dioctylacetamide) (T12C4ODGA), was synthesized and evaluated for the extraction of different actinide and lanthanide ions, viz. Am3+, Eu3+, Pu4+, Np4+, and UO22+. The extraction efficiency of the present ligand was found to be the highest reported so far, more specifically for the trivalent metal ions Am3+ and Eu3+, when one considers the very low ligand concentration used in the present study, compared to that of the various previously reported multiple DGA-based ligands. The nature of the complexes formed during the extraction of Eu3+ was investigated using time-resolved fluorescence (TRFS) and extended X-ray absorption fine structure (EXAFS) spectroscopy. Both the solvent extraction and TRFS studies indicated the presence of 1:1 and 1:2 complexes during the extraction of Am3+ and Eu3+ having three inner-sphere water molecules in the 1:1 complex. Density functional theoretical (DFT) studies were performed on the Am3+ and Eu3+ complexes of both T12C4ODGA and an analogous compound having methyl groups in place of the n-octyl groups, and the DFT results of the T12C4ODGA nicely explain the extraction behavior of Am3+ and Eu3+.