1. Department of Chemical and Pharmaceutical SciencesUniversity of Trieste Via L. Giorgieri 1 34127 Trieste Italy
2. Current address: Institut de Chimie de StrasbourgUniversité de Strasbourg rue Blaise Pascal 4 67000 Strasbourg France
3. Department of Chemical and Pharmaceutical SciencesUniversity of Ferrara Via L. Borsari 46 44121 Ferrara Italy
4. Institut für Organische Chemie & Center for Nanosystems ChemistryUniversität Würzburg Am Hubland 97074 Würzburg Germany