Characterization and Solution Properties of Quaternary-Ammonium-Salt-Type Amphiphilic Gemini Ionic Liquids
Characterization and Solution Properties of Quaternary-Ammonium-Salt-Type Amphiphilic Gemini Ionic Liquids
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DOI：
10.1021/acsomega.9b01660
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发表时间：
2019-09-03
期刊：
影响因子：
4.1
通讯作者：
Yoshimura, Tomokazu
中科院分区：
文献类型：
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作者：
Kawai, Risa;Yada, Shiho;Yoshimura, Tomokazu
季铵盐型两亲性双子化合物（C-m-2-CnX，其中m和n代表烷基链长度；m = 4, 6, 8, 10；n = 2, 4, 6, 8, 10；m n；X表示抗衡离子BF4，PF6，OTf，FSA或NTf2）通过季铵化合成N,N,N',N'四甲基乙二胺和正烷基溴以及随后与五种不同抗衡离子的离子交换反应。为了进行比较，还合成了相应的单体化合物（C-n、X、n = 2、4、6、8和10）。采用差示扫描量热法评估了化合物的熔点，熔点低于100℃的化合物在后续测量中被视为离子液体。当大体积的 NTf2- 为抗衡离子并且两个烷基链之间的不对称度为 0.4 < n/m < 0.75 时，两亲性双子化合物表现出最低的熔点（44-49 ℃）。然而，它们的熔点与 NTf2-7 和 n = 4-10 的单体化合物的熔点并不相似（
Quaternary-ammonium-salt-type amphiphilic gemini compounds (C-m-2-CnX, where m and n represent the alkyl chain lengths; m = 4, 6, 8, 10; n = 2, 4, 6, 8, 10; m n; and X indicates the counterion BF4, PF6, OTf, FSA, or NTf2) were synthesized by the quaternization of N,N,N',N'tetramethylethylenediamine and n-alkyl bromide and a subsequent ion-exchange reaction with five different counterions. For comparison, the corresponding monomeric compounds (C-n, X, n = 2, 4, 6, 8, and 10) were also synthesized. The melting points of the compounds were evaluated using differential scanning calorimetry, and those with melting points lower than 100 degrees C were treated as ionic liquids during the subsequent measurements. The amphiphilic gemini compounds exhibited the lowest melting points (44-49 degrees C) when bulky NTf2- was the counterion and the degree of dissymmetry between the two alkyl chains was 0.4 < n/m < 0.75. However, their melting points were not similar to those of the monomeric compounds with NTf2- 7 and n = 4-10 (