This priority programme is dedicated to improving understanding of the special nature of ionic liquids through fundamental research. Therefore, the main goal of the programme is the detailed investigation of the interactions between the components of an ionic liquid (ions and ion clusters), on the one hand, and of the nature of interactions between ionic liquids and dissolved substances or between ionic liquids and interphases, on the other. It is hoped that this research effort will lead to experimentally validated models that will enable the structural optimization of ionic liquids to achieve given or desired property profiles. Such models are considered to be the key to accelerating future development in the field of ionic liquid research.

This priority program has a strong interdisciplinary character and covers the areas of inorganic, organic, physical, technical and theoretical chemistry as well as chemical engineering.

The three central research fields of the programme are briefly outlined below.

1. Order, dynamics and structure of ionic liquids

In the past very few systematic studies have been carried out to elucidate the order, dynamics and structure of ionic liquids. However, in these few investigations a number of interesting and unusual phenomena have been observed which should be explained, understood and further developed in this part of the program.

Examples of such phenomena are ion cluster formation and the liquid crystalline behaviour of some ionic liquids. The contributions of different influences (Coulombic interaction, hydrogen-bonding, van-der-Waals forces) to these effects have to be understood and will have to be discussed in the light of specific chemical structures of cation/anion combinations. Such phenomena are expected to greatly influence macroscopic properties (such as e.g. conductivity and viscosity) and reactivity. The development, optimization and application of suitable theoretical and experimental tools are expected to be of great relevance within this part of the programme.

2. Interaction of ionic liquids with dissolved substances and interphase interactions

In this part of the programme the specific solvation properties of ionic liquids and their interphase interactions will be investigated. All projects addressing this field should be capable of providing general information and relevant conclusions on structure-forming effects and special interactions in the systems under investigation. The insight obtained from these experiments should allow a knowledge-based tuning of the ionic liquid’s chemical structure in order to enhance or weaken the observed effects.

Examples of probes for the solvation experiments may include molecular compounds of different polarity, dissolved ions, electrons, metal complexes or transition states of reactions. Examples of interphase-ionic liquid interactions may include interactions with surfaces of metals (e.g. under electrochemical control), with organic or inorganic solids (e.g. polymers, nanoparticles or highly porous supports) as well as with the surfaces of poorly miscible or immiscible fluids.

Again, the development, optimization and application of suitable theoretical and experimental, direct (e.g. quantum mechanical calculations, force-field-based simulations, scanning probe microscopies or spectroscopic methods) and indirect methodologies (e. g. thermodynamic investigations, kinetic investigations) will be of great relevance within this part of the programme.

3. New structures forming ionic liquids