Roman Elfgen

Solvents at complex interfaces and as reaction media characterized by spectroscopic, structural and dynamic properties

  • Understanding of pure ionic liquids (ILs) and mixtures: Simulation and analysis in order to gain detailed insight on the molecular level; Discovery and subsequent tuning of working principles by examining fundamental interactions, such as the solvent's (nano)structure in absence and presence of a solute, eventually leading to an increased performance
  • Characterisation of different interfaces: Gain insight into the complex behavior of nanoparticles within highly structured liquids, e.g., the role of nanoparticles and their effect on physicochemical properties and orientation of the IL and how ILs affect the formation of nanoparticles during their synthesis; Examination of solid-liquid and liquid-vapor interfaces; Investigation of chemical reactions in ILs
  • Development of the program TRAVIS for the analysis and visualization of MD trajectories: Implementation of new methods being able to characterize interfaces and the calculation of vibrational spectra, e.g., sum-frequency generation (SFG) spectra
  • The results of the project should help to understand and suggest improved solvents for energy applications in the frame of homogeneous and heterogeneous catalytic processes


Ray, P.; Elfgen, R.; Kirchner, B., Cation influence on heterocyclic ammonium ionic liquids: a molecular dynamics study, Phys. Chem. Chem. Phys. 2019, 21, 4472-4486,

Macchieraldo, R.; Esser, L.; Elfgen, R.; Voepel, P.; Zahn, S.; Smarsly, B. M.; Kirchner, B., Hydrophilic ionic liquid mixtures of weakly and strongly coordinating anions with and without water. ACS Omega 2018, 3, 8567-8582,

Elfgen, R.; Holloczki, O.; Kirchner, B., A molecular level understanding of template effects in ionic liquids. Acc. Chem. Res. 2017, 50, 2949-2957,

Elfgen, R.; Hollóczki, O.; Ray, P.; Groh, M. F.; Ruck, M.; Kirchner, B., Theoretical investigation if the Te4Br2 molecule in ionic liquids. Z. Anorg. Allg. Chem. 2016, 643, 41-52,

Roman Elfgen

Group: Prof. Kirchner, Mulliken Center for Theoretical Chemistry, Rheinische Friedrich-Wilhelms-Universität Bonn