Synthesis, Stability and Electrochemical Characterization of New Ionic Liquids Based on Asymmetrical Borates

基于不对称硼酸盐的新型离子液体的合成、稳定性及电化学表征

• 批准号: 29037138
• 负责人: Professor Dr. Heiner J. Gores
• 金额: --
• 依托单位: Institut für Physikalische und Theoretische Chemie
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2006
• 资助国家: 德国
• 起止时间: 2005-12-31 至 2008-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/29037138?language=en
• 关键词: Synthesis; Stability; Electrochemical; Characterization; New

It is well known that lack of symmetry entails a drop in the fusion point of nearly equal substances. E.g., ethylene carbonate shows a fusion point of about +36°C whereas the liquid range of propylene carbonate extends to roughly -49°C despite its higher molar mass and may be easily supercooled to about -80°C. Thus larger liquid ranges may be obtained for ionic liquids (ILs) based on asymmetric borates when compared to known ILs which are based on symmetric borates such, e.g. EMIBF4. Some asymmetric borates with lithium counter ions are already known. However they show a lack of chemical stability. Exchange reactions entail mixtures of the symmetric and asymmetric borates. We have assumed that this exchange reaction is mainly assisted by the very small lithium ion and tried to synthesize some salts with asymmetric borates and inert cations such as imidazolium ions. Our promising preliminary work showed that our assumption is correct. The first thermally stable member of a new class of ILs was synthesised, tetraethylammoniumdifluoromono1, 2-oxalato(2-)-O,O¿]borate (1-). Therefore we propose a project including synthesis and electrochemical characterisation of new ILs based on asymmetric borates with one- and bidentate ligands and cations of imidazolium, sulfonium and ammonium types. In addition, a long time stability investigation is planned at moderate temperatures, where the composition of the solution of above mentioned borates is studied by NMR-measurements over a long period.

众所周知，不对称会使几乎相等的物质的熔点下降。例如，碳酸乙烯的熔点约为+36°C，而碳酸丙烯的液体范围可延伸至大约-49°C，尽管其摩尔质量较高，并且可以容易地过冷至约-80°C。因此，与基于对称硼酸盐的已知离子液体（例如EMIBF4）相比，基于不对称硼酸盐的离子液体（ILs）可以获得更大的液体范围。一些不对称硼酸盐与锂反离子已经被发现。然而，它们缺乏化学稳定性。交换反应需要对称硼酸盐和不对称硼酸盐的混合物。我们假设这种交换反应主要是由极小的锂离子辅助的，并尝试用不对称硼酸盐和咪唑离子等惰性阳离子合成一些盐。初步工作表明，我们的假设是正确的。合成了一类新化合物的第一个热稳定分子：四乙基二氟铵- 1,2 -草酸(2-)-O，O¿]硼酸盐（1-）。因此，我们提出了一个项目，包括合成和电化学表征新的非对称硼酸盐与咪唑、磺胺和铵型阳离子的单齿和双齿配体和阳离子。此外，计划在中等温度下进行长期稳定性研究，其中通过核磁共振测量长时间研究上述硼酸盐溶液的组成。