1. Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry (MPIBPC), Am Fassberg 11, 37077 Göttingen, Germany
2. Facility for Synthetic Chemistry, MPIBPC, Am Fassberg 11, 37077 Göttingen, Germany
3. Institut für Organische und Biomolekulare Chemie der Georg-August-Universität, Tammannstrasse 2, 37077 Göttingen, Germany