Ionization state and ion migration mechanism of room temperature molten dialkylimidazolium fluorohydrogenates.
Ionization state and ion migration mechanism of room temperature molten dialkylimidazolium fluorohydrogenates.
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DOI：
10.1021/jp0459110
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发表时间：
2005-02
期刊：
影响因子：
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通讯作者：
Yuria Saito;K. Hirai;K. Matsumoto;R. Hagiwara;Yoshihiro Minamizaki
中科院分区：
文献类型：
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作者：
Yuria Saito;K. Hirai;K. Matsumoto;R. Hagiwara;Yoshihiro Minamizaki
利用Stokes-Einstein关系，从扩散系数和粘度两个方面研究了室温熔盐（RMIm（HF）（2.3）F：R =烷基，M =甲基）的电离态.假设盐的解离度对于熔融盐的离子状态的表示是可接受的，随着烷基链的伸长，阳离子尺寸越大，盐的解离度越高。此外，我们提出了“阴阳离子有序度”的概念更适合于表征无溶剂物种的电离态。在此基础上，RMIm（HF）（2.3）F盐的阳离子尺寸越小，离子的有序度越高，表明形成了聚集离子的畴粒子作为移动的物种的单元，例如A+ X-盐的A（AX）m+和X（AX）n-。结果发现，高度有序的颗粒，与大量的m和n，表现出高的扩散系数。
The ionization state of room temperature molten salts, alkylimidazolium fluorohydrogenates (RMIm(HF)(2.3)F: R = alkyl group, M =methyl group), was evaluated from the observed diffusion coefficient and viscosity, using the Stokes-Einstein relation. Assuming that the dissociation degree of the salt is acceptable for representation of the ionic state of the molten salts, the larger the cation size with elongation of the alkyl chain was, the higher the dissociation degree of the salt. Further, we proposed that an idea of the "degree of ordering of cations and anions" was more suitable to represent the ionization state without solvent species. On the basis of this idea, the smaller the cation size of RMIm(HF)(2.3)F salt was, the higher the ordering of the ion, indicating formation of domain particles of aggregated ions as a unit of mobile species such as A(AX)m+ and X(AX)n- for A+ X- salt. It was found that highly ordered particles, with large numbers for m and n, showed a high diffusion coefficient.