1. a Università di Messina, Dipartimento di Chimica Organica e Biologica , Salita Sperone 31, I-98166, Messina, Italy
2. b Faculty of Chemistry, Wroclaw University of Technology , Wybrzeze Wyspianskiego 27, 50-370, Wroclaw, Poland
3. c CNR, ICTP Catania , Viale Regina Margherita 6, I-95125, Catania, Italy