1. Department of Chemistry, Johannes Gutenberg Universität Mainz, 55099 Mainz, Germany
2. Chair in Polymer Chemistry, Saarland University, 66123 Saarbrücken, Germany
3. INM—Leibniz Institute for New Materials, Campus D2 2, Saarland University, 66123 Saarbrücken, Germany
4. Department of Physics, University of Ioannina, P. O. Box 1186, 451 10 Ioannina, Greece
5. Max Planck Institute for Polymer Research, 55128 Mainz, Germany