Laser-induced fluorescence and infrared spectroscopic studies on the specific solvation of tris(1-(2-thienyl)-4,4,4-trifluoro-1,3-butanedionato)europium(III) in an ionic liquid
Laser-induced fluorescence and infrared spectroscopic studies on the specific solvation of tris(1-(2-thienyl)-4,4,4-trifluoro-1,3-butanedionato)europium(III) in an ionic liquid
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离子液体中三(1-(2-噻吩基)-4,4,4-三氟-1,3-丁二酮)铕(III)特异性溶剂化的激光诱导荧光和红外光谱研究
DOI：
10.1016/j.poly.2011.10.031
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发表时间：
2012
期刊：
影响因子：
2.6
通讯作者：
Hiroyuki Okamura
中科院分区：
文献类型：
--
作者：
岸本督司;古川真宏;渡辺洋平;Kojiro Shimojo;Hiroyuki Okamura;Hiroyuki Okamura
通过考虑阴离子四（2-thenoyltrifluoroacetonato）europate（III）的萃取平衡，确定了三（2-thenoyltrifluoroacetonato）europium（III）在1-丁基-3-甲基咪唑双（三氟甲磺酰基）亚胺（[C4mim][Tf2N]）作为离子液体和水相之间的萃取常数和两相稳定常数（KD, m - β3）。由于[C4mim][Tf2N]体系比在苯和1,2-二氯乙烷等常规分子溶剂中具有更高的KD，M - β3值，因此中性Eu（III）螯合物与[C4mim][Tf2N]分子的分布常数与[C4mim][Tf2N]分子的分布常数（KD，M）之间的关系揭示了中性Eu（III）螯合物与[C4mim][Tf2N]分子之间的特殊溶质-溶剂相互作用。采用时间分辨激光诱导荧光光谱和红外吸收光谱研究了中性Eu（III）螯合物[C4mim][Tf2N]中Eu3+的配位环境。两种方法一致表明，不仅提取的Eu（III）螯合物，而且合成的固态Eu(tta)3(H2O)3在[C4mim][Tf2N]中几乎完全脱水。因此，中性Eu（III）螯合物在[C4mim][Tf2N]体系中的KD越高，可提取率越高，这可归因于Eu（III）螯合物的脱水，这是由[C4mim][Tf2N]分子的特定溶剂化引起的。
The extraction constant and the two-phase stability constant (KD,Mβ3) of tris(2-thenoyltrifluoroacetonato)europium(III) between 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([C4mim][Tf2N]) as an ionic liquid and an aqueous phase were determined by considering the extraction equilibria including anionic tetrakis(2-thenoyltrifluoroacetonato)europate(III). Specific solute–solvent interactions between the neutral Eu(III) chelate and [C4mim][Tf2N] molecules were revealed from the relationships between the distribution constant of the enol form of 2-thenoyltrifluoroacetone (Htta) as a proton chelate and the distribution constant (KD,M) of the neutral Eu(III) chelate because the [C4mim][Tf2N] system gave the high KD,Mβ3value compared with those in conventional molecular solvents such as benzene and 1,2-dichloroethane. The coordination environment of Eu3+in the neutral Eu(III) chelate in [C4mim][Tf2N] was investigated by time-resolved laser-induced fluorescence spectroscopy and infrared absorption spectroscopy. Both methods consistently indicated that not only the Eu(III) chelate extracted but also Eu(tta)3(H2O)3synthesized as a solid crystal were almost completely dehydrated in [C4mim][Tf2N] saturated with water. Consequently, the higher KD,Mor extractability of the neutral Eu(III) chelate in the [C4mim][Tf2N] system can be ascribed to the dehydration of the Eu(III) chelate, which is caused by the specific solvation with [C4mim][Tf2N] molecules.