Ultrafast relaxation dynamics of ionic liquids using solvated electrons as a probe

• Applicant: Professor Dr. Andreas-Neil Unterreiner
• Subject Area: Physical Chemistry of Molecules, Liquids and Interfaces, Biophysical Chemistry
• Term: from 2006 to 2009
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 29140456

In this project the ultrafast relaxation dynamics of ionic liquids will be investigated upon photolytic generation of solvated electrons. Experimental techniques such as femtosecond pump-probe absorption and polarization-sensitive spectroscopy with a time resolution of ¿ 100fs will be used to study fundamental inter- and intramolecular interactions in these liquids. As a spectroscopic probe solvated electrons will be generated photolytically and the subsequent relaxation processes will be monitored. While transient absorption techniques can identify and characterize the optical response of solvated electrons in such liquids, polarization-dependent spectroscopy will direct the focus towards structural and electronic properties. For example, two- and three-pulse sequences will allow for a characterization of the formation, recombination and relaxation steps of solvated electrons using time-resolved absorption spectroscopy. On the other hand, transient anisotropy as a polarization-sensitive tool explores the time-dependent orientational changes of solvated electrons in ionic liquids. The results of these studies can be compared to the ultrafast dynamics of solvated electrons in high-temperature ionic liquids where Coulombic interactions in combination with diffusive ionic motions determine the ultrafast response. As a result, this study will provide a more profound understanding of the underlying photo-chemical and photo-physical processes in ionic liquids.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1191: Ionic Liquids
• Major Instrumentation: Erbium fibre femtosecond laser oscillator
• Instrumentation Group: 5700 Festkörper-Laser