1. Physics Department E20, Technical University of Munich, Garching D-85748, Germany
2. School of Chemistry, Chair of Organic Chemistry, Trinity Biomedical Sciences Institute, Trinity College Dublin, the University of Dublin, 152-160 Pearse Street, Dublin 2, Ireland
3. Institute for Advanced Study (TUM-IAS), Technical University of Munich, Focus Group – Molecular and Interfacial Engineering of Organic Nanosystems, Lichtenberg-Str. 2a, 85748 Garching, Germany
4. Department of Chemistry, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario, P7B 5E1, Canada, M. E. is a Tier 2 Canada Research Chair in Low-Dimensional Nanomaterials