1. Istituto CNR di Scienze e Tecnologie Molecolari (CNR-ISTM), c/o Dipartimento di Chimica, Università di Perugia, Via elce di Sotto 8, I-06213 Perugia, Italy
2. Laboratory for Photonics and Interfaces, Station 6, Institute of Chemical Sciences and Engineering, School of Basic Sciences, Swiss Federal Institute of Technology, CH-1015 Lausanne, Switzerland