Physicochemical Characterization of MFm鈥?/sup>-Based Ammonium Ionic Liquids

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• 作者：Haifang Li ; Guoying Zhao ; Fangfang Liu ; Suojiang Zhang
• 刊名：Journal of Chemical & Engineering Data
• 出版年：2013
• 出版时间：June 13, 2013
• 年：2013
• 卷：58
• 期：6
• 页码：1505-1515
• 全文大小：498K
• 年卷期：v.58,no.6(June 13, 2013)
• ISSN：1520-5134

文摘

A series of ammonium-based ionic liquids (ILs), which share a homologous series of cations (CH₃CH₂)₃N⁺(C_nH_2n+1) with n = 2, 4, 6, 8 and the anions with either BF₄^{鈥?/sup>, PF₆鈥?/sup>, or SbF₆鈥?/sup>, was synthesized. Their structures were confirmed by 1H and 13C NMR, ESI-MS, and elemental analysis. Meanwhile, the content of impurity (e.g., water and bromide ions) was also determined using Karl Fischer titrator and ion chromatography. The thermal properties of the ILs were determined by TGA and DSC. Five of the investigated ILs have been shown to have a low melting point (< 100 掳C): N,N,N,N-tetraethylammonium tetrafluoroborate, [N₂₂₂₂]BF₄, N,N,N,N-tetraethylammonium hexafluorophosphate, [N₂₂₂₂]PF₆, N,N,N-triethylhexylammonium tetrafluoroborate, [N₂₂₂₆]BF₄, N,N,N-triethyloctylammonium hexafluorophosphate, [N₂₂₂₈]PF₆ and N,N,N-triethyloctylammonium hexafluoroantimonate, [N₂₂₂₈]SbF₆. Densities, refractive indices, and miscibility of these 12 ILs were well studied systematically. Moreover, from the analysis of the structure鈥損roperty relationship, the role of the alkyl chain length of the cation on these physical properties of the ILs has been assessed, and the influence of the nature of the anions on these experimental data of the ILs has been discussed. The studies may provide valuable contributions for the design and study of ILs.}