goals of the research unit
The aggregation of molecules to form well-defined clusters up to macroscopic crystals is a fascinating phenomenon. However, details of this process are still not well understood. The weak intermolecular interactions leading to aggregation are difficult to investigate, both experimentally and theoretically. Until now, the prediction of the structure of molecule crystals is still an unsolved problem of chemistry, since especially the dynamic processes leading from the nucleation of a few molecules to the macroscopic crystal are not well understood. The goal of the research unit is thus to obtain a detailed understanding of aggregation phenomena – from dimers to larger aggregates as nucleation centers to extended molecule crystals. The aggregation of selected systems will be investigated in all details both experimentally and theoretically. This involves the determination of structures, energies and kinetic data on all levels of aggregation.
To achieve these goals the focus will be on small molecules which allow for the quantitative determination of intermolecular interactions. The experimental techniques involve the spectroscopic characterization of aggregates of small molecules in the gas phase, in molecular beams, in suprafluid ultra-cold helium droplets, as well as in inert gas matrices. Theoretical methods used involve the quantitative calculation of intermolecular interactions, quantum Monte Carlo simulations, and ab-initio molecular dynamics of aggregates. This broad spectrum of methods allows to investigate the aggregation in the gas phase, in molecular beams, in matrices, and in the solid state from single molecules to molecule crystals. Of importance is the quantitative determination of structural parameters and intermolecular interactions as well as the investigation of the dynamics of aggregations. The long term goal is not only to understand aggregation, but to predict it quantitatively based on molecular properties.