1. Dipartimento di Scienze Chimiche Università degli Studi di Catania Viale Andrea Doria 6 95125 Catania Italy
2. Department of Chemistry University of Michigan Ann Arbor MI 48109 USA
3. Institute of Crystallography National Research Council (CNR), S.S. Catania Via P. Gaifami 18 95126 Catania Italy
4. Department of Chemistry Life Sciences and Environmental Sustainability University of Parma Parco Area delle Scienze 17 A 43124 Parma Italy