1. Center for Nanotechnology, Heisenberg Straße 11, Münster 48149, Germany
2. Department of Physics, Münster University, Wilhelm-Klemm-Straße 10, Münster 48149, Germany
3. School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
4. Institute of Organic Chemistry, Justus Liebig University, Heinrich-Buff-Ring 17, and Center for Materials Research (LaMa), Justus Liebig University, Heinrich-Buff-Ring 16, Giessen 35392, Germany
5. Department of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička cesta 54, Zagreb 10 000, Croatia
6. Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr 45470, Germany
7. Institute of Organic Chemistry, Münster University, Correns Straße 40, Münster 48149, Germany