Synergistic Effect of 18-Crown-6 Derivatives on Chelate Extraction of Lanthanoids(III) into an Ionic Liquid with 2-Thenoyltrifluoroacetone
Synergistic Effect of 18-Crown-6 Derivatives on Chelate Extraction of Lanthanoids(III) into an Ionic Liquid with 2-Thenoyltrifluoroacetone
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DOI：
10.2116/analsci.26.607
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发表时间：
2010-05-01
影响因子：
1.6
通讯作者：
Imura, Hisanori
中科院分区：
文献类型：
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作者：
Okamura, Hiroyuki;Hirayama, Naoki;Imura, Hisanori
研究了18-冠-6（18 C6）、顺二环己基-18-冠-6（DC 18 C6）和二苯并-18-冠-6（DB 18 C6）对离子液体1-丁基-3-甲基咪唑双（三氟甲磺酰基）酰亚胺与2-噻吩甲酰三氟丙酮（Htta）萃取三价镧系元素（Ln（3+））的协同效应.加入18 C6或DC 18 C6可提高较轻Ln（3+）的萃取率，而加入DB 18 C6则没有提高萃取率。此外，冠醚（CE）的协同效应随着Ln原子序数的降低而沿着增加。在协同萃取体系中，Ln（3+）以Ln（tta）（2）（CE）（+）和Ln（tta）（CE）（2+）的形式被萃取，表明Ln（tta）（CE）（2+）络合物作为萃取物种的形成导致了较大的协同效应。这种协同效应源于CE对Ln（3+）络合的尺寸拟合效应。
The synergistic effect of 18-crown-6 derivatives, such as 18-crown-6 (18C6), cis-dicyclohexano-18-crown-6 (DC18C6) and dibenzo-18-crown-6 (DB 18C6), on the extraction of trivalent lanthanoids (Ln(3+)) into an ionic liquid, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, with 2-thenoyltrifluoroacetone (Htta) was investigated. The extractability of lighter Ln(3+) was enhanced by adding 18C6 or DC18C6, whereas no enhancement of the extractability was observed by adding DB 18C6. Moreover, the synergistic effect by the crown ether (CE) was increased along with the decrease in the atomic number of Ln. In the synergistic extraction system, Ln(3+) was extracted as cationic ternary complexes Ln(tta)(2)(CE)(+) and Ln(tta)(CE)(2+), and it was suggested that the formation of the Ln(tta)(CE)(2+) complex as an extracted species results in the large synergistic effect. This synergistic effect originated in a size-fitting effect of CE on complexation to Ln(3+).