1. Department of Chemistry, NIS and INSTM Reference Centre Università di Torino Via G. Quarello 15, I-10135 and Via P. Giuria 7 10125 Torino Italy
2. TASC Laboratory, IOM-CNR S.S. 14 km 163.5 Basovizza 34149 Trieste Italy
3. Center for Materials Science and Nanotechnology (SMN), Department of Chemistry University of Oslo 1033 Blindern 0315 Oslo Norway