Mobility of hydrated alkali metal ions in metallosupramolecular ionic crystals
Mobility of hydrated alkali metal ions in metallosupramolecular ionic crystals
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DOI：
10.1039/c8sc04204g
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发表时间：
2019-01-14
期刊：
影响因子：
8.4
通讯作者：
Konno, Takumi
中科院分区：
文献类型：
--
作者：
Yoshinari, Nobuto;Yamashita, Satoshi;Konno, Takumi
离子晶体的设计和制备显示出固态离子物种的高迁移率，这不仅是因为这些材料的实际应用，也是因为这种离子物种与离子传输生物系统的相关性，所以长期以来一直是人们非常关注的研究课题。本文报道了碱金属离子(M=Li+，Na+，K+)在离子晶体M-6[Rh4Zn4O(L-半胱酸盐)(12)]NH(2)O(M-6[1]NH(2)O)中的迁移率。在M-6[1]NH(2)O中，碱金属离子与许多水分子一起无序地分布在[1](6-)阴离子团簇的刚性氢键骨架内。M-6[1]NH(2)O的固态交流电导率按Li-6[1]NH(2)O<；Na-6[1]NH(2)O<；K-6[1]NH(2)O的顺序增加，与裸离子半径的顺序相反。在300K下，K-6[1]NH(2)O单晶的电导率达到了σ=1.3×10(-2)S cm(-1)的上峰。这些结果反映了固体核磁共振谱支持的碱金属水合离子在M-6[1]NH(2)O晶格中的高迁移率，并结合固体中的离子扩散实验进行了验证。高的迁移率导致K-6[1]NH(2)O中的K+离子与Li+和Na+离子快速交换，并保持了单晶性。
The design and creation of ionic crystals that show high mobility of ionic species in the solid state has long been a research topic of considerable attention not only due to the practical applications of these materials but also due to the correlation of such ionic species with ion-transport biological systems. In this work, we report the mobility of alkali metal ions (M = Li+, Na+, K+) in the ionic crystals M-6[Rh4Zn4O (l-cysteinate)(12)]nH(2)O (M-6[1]nH(2)O). In M-6[1]nH(2)O, alkali metal ions are distributed in a disordered manner, together with a number of water molecules, within a rigid hydrogen-bonded framework of anionic clusters of [1](6-). The alternating current conductivities of M-6[1]nH(2)O in the solid state increase in the order of Li-6[1]nH(2)O < Na-6[1]nH(2)O < K-6[1]nH(2)O, which is opposite to the order of the naked ionic radii. The conductivities reach the superionic level of sigma = 1.3 x 10(-2) S cm(-1) at 300 K for a single crystal of K-6[1]nH(2)O. These results reflect the high mobility of hydrated alkali metal ions in the crystal lattice of M-6[1]nH(2)O, which is supported by solid-state NMR spectroscopy, together with ion diffusion experiments in the solid state. The high mobility leads to quick exchange of K+ ions in K-6[1]nH(2)O with Li+ and Na+ ions with retention of single crystallinity.