1. Istituto di Chimica Biomolecolare, CNR, via Campi Flegrei 34, Comprensorio A. Olivetti, Ed. 70, 80078 Pozzuoli (NA), Italy, Department of Chemistry, University of Basilicata, via N. Sauro 85, 85100 Potenza, Italy, and Department of Chemistry and Centro SCS, University of Modena and Reggio Emilia, via Campi 183, 41100 Modena, Italy