Read the full text of the article at 10.1002/cplu.201200267
Invited for this month’s cover are the groups of Prof. Ingo Krossing and Prof. Peter Woias based at Albert-Ludwigs-Universität Freiburg as well as Prof. Carsten Knapp who is now at Bergische Universität Wuppertal. The background of the cover picture shows the Rhine Falls (Schaffhausen, Switzerland), which is the largest waterfall in Europe and only one hour away from the laboratories in Freiburg. The waterfall symbolizes flow chemistry and the wild nature of direct fluorination reactions.
Why did you decide to work on direct fluorination?
12Fluorine plays an important role in chemistry as well as in material and life sciences. However, the number of scientific groups working with elemental fluorine has steadily decreased over the past few years. Because of the fundamental importance of fluorine and fluorination reactions, it was strategically decided to make direct fluorination chemistry part of the program at the University of Freiburg. The fact that practically all results from the Krossing group, in basic research as well in applied fields, were based on fluorinated molecules provided additional motivation. Accordingly, it was decided to do work with this unique element itself. And with the Woias group on board we set about designing and developing to a novel, micro-structured device for direct fluorinations. The Knapp group later joined the project and contributed knowledge of the synthesis of boron clusters and their halogenations.
What other topics are you working on at the moment?
This collaboration is continuing and as part of the next stage of the current project we are advancing the technology from nickel-plated copper blocks and machine-drilled minichannels to classical silicon technology at the microscale with the inclusion of as many sensors as possible. This device will facilitate our ongoing efforts in the synthesis and understanding of ionic systems, featuring highly fluorinated weakly coordinating anions or Lewis acids. Brønsted acids, highly reactive cations, polymerizations, ionic liquids, and electrolytes for lithium-ion batteries are the focus of our interest. Quantum chemical calculations are an accompanying tool that we use at rather advanced levels in the sense of computer-aided synthesis.
We thank the German Science Foundation (DFG) for financial support and Solvay Fluor GmbH for donating the fluorine and monofluoroethylene carbonate. Everybody who contributed to this project is really appreciated, especially the students who helped in research projects to establish a working reactor system: J. Hillert, J. Hoeser, P. Bendix, F. Brosi, A. Rupp, and B. Burgenmeister.