1. Department of Functional Materials University of Bayreuth Bayreuth 95440 Germany
2. Soft Matter Optoelectronics University of Bayreuth Bayreuth 95440 Germany
3. Institute for Molecules and Materials Radboud University Nijmegen 6525 AJ (The Netherlands
4. Northern Bavarian NMR Centre (NBNC) and Inorganic Chemistry University of Bayreuth Bayreuth 95440 Germany