Complex Formation of Lanthanide Ions with Sulfonated Crown Ethers in Aqueous Solution.
Complex Formation of Lanthanide Ions with Sulfonated Crown Ethers in Aqueous Solution.
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镧系离子与磺化冠醚在水溶液中形成络合物。
DOI：
10.1002/chin.199820208
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
Z. Yoshida
中科院分区：
文献类型：
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作者：
T. Sasaki;S. Umetani;M. Matsui;S. Tsurubou;T. Kimura;Z. Yoshida
新型水溶性冠醚（3′-sulfoBenz-12-crown-4 (SB12C4)、3′-sulfoBenz-15-crown-5 (SB15C5)、3′-sulfoBenz-18-crown-6 (SB18C6)、di(3′-sulfo)diBenzo-18-crown-6 (DSDB18C6)、已经制备了二(3'-磺基)二苯并-21-冠-7 (DSDB21C7)和二(3'-磺基)二苯并-24-冠-8 (DSDB24C8))。通过溶剂萃取法测定了水溶液中稀土离子与磺化冠醚的络合物形成常数（β）。所得复合物的稳定性随着磺酸基团的数量而增加，18C6 < SB18C6 < DSDB18C6。对于单磺化冠醚配合物和二磺化冠醚配合物，稳定性变化如下：SB18C6 < SB15C5 < SB12C4 和 DSDB18C6 < DSDB21C7 < DSDB24C8。所有镧系离子配合物的β值都随着原子序数的增加而减小，这是大环配体的特征，与常规的络合趋势相反。通过将磺化冠醚作为离子尺寸选择性掩蔽剂添加到水相中，可以改善镧系元素离子的萃取分离性。通过激光诱导发光研究确定复合物中心 Eu3+ 的第一配位层中水分子的数量。此外，测量荧光光谱以评价复合物的结构。讨论了形成的配合物的稳定性，同时考虑了磺酸基团和金属离子之间的外层静电引力。
A new type of water-soluble crown ether (3′-sulfobenzo-12-crown-4 (SB12C4), 3′-sulfobenzo-15-crown-5 (SB15C5), 3′-sulfobenzo-18-crown-6 (SB18C6), di(3′-sulfo)dibenzo-18-crown-6 (DSDB18C6), di(3′-sulfo)dibenzo-21-crown-7 (DSDB21C7), and di(3′-sulfo)dibenzo-24-crown-8 (DSDB24C8)) has been prepared. The complex formation constants (β) of lanthanide ions with sulfonated crown ethers in aqueous solution were determined via the solvent-extraction method. The stability of the resulting complexes increases with the number of sulfonic acid groups, 18C6 < SB18C6 < DSDB18C6. For mono and disulfonated crown ether complexes, the stability varies as SB18C6 < SB15C5 < SB12C4 and DSDB18C6 < DSDB21C7 < DSDB24C8. Theβvalues of all the complexes of lanthanide ions decrease with the atomic number, which is a characteristic of macrocyclic ligands, and is quite opposite to the conventional complexing tendency. The extractive separability of lanthanide ions was found to improve by adding sulfonated crown ethers into the aqueous phase as ion-size selective masking reagents. The number of water molecules in the first coordination sphere of the central Eu3+in the complex was determined by a laser-induced luminescence study. In addition, the fluorescence spectra were measured in order to evaluate the structure of the complexes. The stabilization of the complexes formed is discussed while taking into account an outer-sphere electrostatic attraction between the sulfonic acid group and the metal ion.