Intermolecular interactions in ionic liquids studied by THz, far IR and Raman spectroscopy

离子液体的特殊性质取决于其组分之间相互作用的类型和强度。阳离子和阴离子之间的分子间力决定了在这种新的液体材料中是否存在扩展的网络结构、更大的聚集体或离子对。相互作用的强度由不同分子间力之间的相互作用给出。在这个项目中，这些不同类型的力将研究太赫兹，远红外和拉曼光谱。所有的方法都探测了与质子和非质子性离子液体中阳离子和阴离子之间的分子间力直接相关的低频振动模式。更好地理解氢键，聚集和质子转移使得能够调整这些库仑系统中的有利性质。探测阳离子-阴离子相互作用也为开发用于分子动力学和蒙特卡罗模拟的新力场开辟了一条新的道路。这对于质子离子液体（PIL）尤其如此，其中力场发展仍处于起步阶段。

The unusual properties of ionic liquids (ILs) are governed by the type and strength of interaction between its constituents. Intermolecular forces between cation and anion determine whether expanded network structures, larger aggregates or ion-pairs are found in this new liquid material. The strength of interaction is given by an interplay between different intermolecular forces. In this project these different types of forces will be studied by THz, far IR and Raman spectroscopy. All methods probe the lowfrequency vibrational modes which can be directly related to the intermolecular forces between cation and anion in aprotic and protic ionic liquids. A better understanding of hydrogen bonding, aggregation and proton transfer enables to tune the favored properties in these Coulomb systems. Probing the cation-anion interaction also opens a new path for developing new force fields used in molecular dynamics and Monte Carlo simulations. This is in particular true for protic ionic liquids (PILs), where the force field development is still in its infancy.