Competition between hydrogen bonding and dispersion forces in ionic and molecular liquids by means of spectroscopic and thermodynamic methods

利用光谱和热力学方法研究离子液体和分子液体中氢键和色散力的竞争

• 批准号: 269854963
• 负责人: Professor Dr. Ralf Ludwig
• 金额: --
• 依托单位: Lehrstuhl für Allgemeine Physikalische Chemie
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/269854963?language=en
• 关键词: Competition; between; hydrogen; bonding; dispersion

The competition between hydrogen bonding and dispersion forces in ionic and molecular liquids will be studied by means of infrared, terahertz, several thermodynamic methods and quantum chemical calculations including dispersion correction. The important role of dispersion forces on the formation of ionic and molecular clusters will be investigated for all phases: the solid, the liquid and the gas phase. The structure of the clusters present in each phase will be determined by X-ray and spectroscopic methods whereas changes during phase transition will be probed by thermodynamic methods. For that purpose, a well selected set of ionic and molecular liquids will be synthesized that allows to control of noncovalent interactions. The special feature of the molecular liquids is that the molecules are mimics of the cations used in the ionic liquids. This way we can study the different role of dispersion forces while changing from ionic to molecular liquids and switching off the strong Coulomb interaction. Moreover, the compounds are designed such that we can increase the dispersion forces in a controlled way while weakening hydrogen bonding at the same time. The combined spectroscopic methods (MIR, FIR, THz), thermodynamic methods (calorimetry, thermogravimetry, vapour pressure measurements) and theoretical approaches (DFT and Gn) allow to study the subtle balance between Coulomb interaction, hydrogen bonding and dispersion forces in these model compounds. In particular the role of dispersion forces can be analyzed in the liquid phase, wherein most practical chemistry occurs.

将通过红外、太赫兹、几种热力学方法和包括色散校正在内的量子化学计算来研究离子和分子液体中氢键和色散力之间的竞争。色散力对离子和分子簇形成的重要作用将在所有相中进行研究：固相、液相和气相。每个相中存在的团簇结构将通过 X 射线和光谱方法确定，而相变期间的变化将通过热力学方法探测。为此，将合成一组经过精心挑选的离子液体和分子液体，以控制非共价相互作用。分子液体的特殊之处在于分子是离子液体中使用的阳离子的模拟物。通过这种方式，我们可以研究从离子液体变为分子液体并关闭强库仑相互作用时色散力的不同作用。此外，这些化合物的设计使得我们可以以受控的方式增加分散力，同时削弱氢键。组合光谱方法（MIR、FIR、THz）、热力学方法（量热法、热重分析、蒸气压测量）和理论方法（DFT 和 Gn）可以研究这些模型化合物中库仑相互作用、氢键和色散力之间的微妙平衡。特别是，可以在液相中分析色散力的作用，其中大多数实际化学反应都发生在液相中。