1. Science and Technology Department, IBM Research Europe Säumerstrasse 4 8803 Rüschlikon Schweiz
2. Department of Chemistry University of Basel St. Johanns-Ring 19 4056 Basel Schweiz
3. Institute for Nanotechnology (INT) Karlsruhe Institute of Technology (KIT) P. O. Box 3640 76021 Karlsruhe Deutschland
4. Lehn Institute of Functional Materials (LIFM) School of Chemistry Sun Yat-Sen University (SYSU) Guangzhou 510275 VR China