Luo Yuan, Marets Nicolas, Kato Takashi
Department of Chemistry and Biotechnology , School of Engineering , The University of Tokyo , Hongo, Bunkyo-ku , Tokyo 113-8656 , Japan . Email:
Chem Sci. 2017 Nov 1;9(3):608-616. doi: 10.1039/c7sc03652c. eCollection 2018 Jan 21.
Lithium is recognized as being significantly important due to its various applications in different areas especially in energy technology. In the present study, self-assembled nanostructured liquid-crystalline (LC) materials, that selectively bind lithium cations, have been developed for the first time. Wedge-shaped crown ether derivatives bearing dibenzo-14-crown-4 (DB14C4) or 12-crown-4 moieties are able to act as LC lithium-selective receptors. We have found that complexation of these receptors with lithium perchlorate induces liquid-crystalline columnar phases, while sodium perchlorate is immiscible with both receptors. Remarkably, a receptor consisting of DB14C4 as an effective lithium-selective ligand exhibits high selectivity for LiCl over NaCl, KCl, RbCl and CsCl. The lithium selectivity was demonstrated and investigated by H NMR, H COSY and FT-IR spectroscopic measurements. The preferred coordination number of four and the ideal cavity geometry of the DB14C4 moiety of the receptor are shown to be key factors for the high lithium selectivity. This new design of LC lithium-selective receptors opens unexplored paths for the development of methods to fabricate nanostructured materials for efficient selective lithium recognition.
锂因其在不同领域尤其是能源技术中的各种应用而被认为具有极其重要的意义。在本研究中，首次开发了能够选择性结合锂离子的自组装纳米结构液晶（LC）材料。带有二苯并-14-冠-4（DB14C4）或12-冠-4基团的楔形冠醚衍生物能够作为液晶锂选择性受体。我们发现这些受体与高氯酸锂的络合会诱导液晶柱状相，而高氯酸钠与这两种受体都不互溶。值得注意的是，由DB14C4作为有效锂选择性配体组成的受体对LiCl的选择性高于NaCl、KCl、RbCl和CsCl。通过1H NMR、1H COSY和FT-IR光谱测量对锂选择性进行了证明和研究。受体的DB14C4部分的优选配位数为4以及理想的空腔几何形状被证明是高锂选择性的关键因素。这种新型液晶锂选择性受体的设计为开发用于高效选择性锂识别的纳米结构材料的方法开辟了未被探索的途径。
