Effect of Dimethyl Carbonate on the Dynamic Properties and Ionicities of Ionic Liquids with [M(III) (hfip)4 ](-) (M=B, Al) Anions.
Effect of Dimethyl Carbonate on the Dynamic Properties and Ionicities of Ionic Liquids with [M(III) (hfip)4 ](-) (M=B, Al) Anions.
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DOI：
10.1002/cphc.201500069
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发表时间：
2015-06
期刊：
影响因子：
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通讯作者：
Alexander B. A. Rupp;Sabrina Welle;Petra Klose;H. Scherer;I. Krossing
中科院分区：
文献类型：
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作者：
Alexander B. A. Rupp;Sabrina Welle;Petra Klose;H. Scherer;I. Krossing
制备了几种包含 [B(hfip)4 ](-) [hfip=OCH(CF3 )2 ] 或 [Al(hfip)4 ](-) 阴离子和咪唑鎓或铵阳离子的离子液体 (IL)，并与高达 270 mol% 的碳酸二甲酯 (DMC) 混合。测量了这些混合物以及可能的纯 IL 的粘度、电导率和自扩散常数，并与常见的基于 [NTf2 ](-) 的 IL 及其与 DMC 的混合物进行了比较。所有类别的离子液体均可实现粘度的大幅降低以及电导率和扩散常数的增加。然而，扩散数据中电导率的顺序部分颠倒。这可能是由于 DMC 的介电常数较低，因此有利于离子配对，如计算的离子度所证明的那样。总而言之，我们的数据表明，化学性质稳定、但熔点高且粘度更大的 [B(hfip)4 ](-) IL 在与合适的分子溶剂混合时可能是电解质的候选者。
Several ionic liquids (ILs) comprising [B(hfip)4 ](-) [hfip=OCH(CF3 )2 ] or [Al(hfip)4 ](-) anions and imidazolium or ammonium cations were prepared and mixed with up to 270 mol % of dimethyl carbonate (DMC). The viscosities, conductivities, and self-diffusion constants of these mixtures and, where possible, of the neat ILs were measured and compared with common [NTf2 ](-) based ILs and their mixtures with DMC. A tremendous decrease of the viscosities and a likewise increase of the conductivities and diffusion constants can be achieved for all classes of ILs. However, the order of the conductivities is partially reversed in the diffusion data. This is probably due to the low dielectric constant of DMC and the, thus, favored ion pairing, as evidenced, for example, by the calculated ionicities. Altogether, our data show that the chemically robust, but high-melting and more viscous [B(hfip)4 ](-) ILs might be candidates for electrolytes when mixed with suitable molecular solvents.