1. Institute of Organic Chemistry and Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen
2. 45141 Essen
3. Germany
4. Department of Physical Chemistry and Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen
5. Kekulé-Institute for Organic Chemistry and Biochemistry, University of Bonn
6. 53121 Bonn
7. Ruhr-Universität Bochum, Organische Chemie II
8. 44801 Bochum