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

离子和分子液体中氢键和色散力之间的竞争将通过红外、太赫兹、几种热力学方法和量子化学计算（包括色散校正）进行研究。分散力对离子和分子团簇形成的重要作用将被研究所有相：固体、液体和气相。每个相中的团簇结构将通过x射线和光谱方法确定，而相变过程中的变化将通过热力学方法进行探测。为此，将合成一组精心挑选的离子和分子液体，以控制非共价相互作用。分子液体的特殊之处在于其分子是离子液体中所用阳离子的仿制品。通过这种方法，我们可以研究从离子液体转变为分子液体和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一种可控的方式增加分散力，同时减弱氢键。结合光谱方法（MIR， FIR, THz），热力学方法（量热法，热重法，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。特别是分散力的作用可以在液相中分析，其中大多数实际化学发生。

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.