1. CQM-Centro de Quı́mica
da Madeira, MMRG, Universidade da Madeira, Campus Universitário da Penteada, 9000-390 Funchal, Portugal
2. Department of Chemistry, NanoScience Center, University of Jyväskylä, P.O. Box 35,
40014 JYU, Finland
3. Physics Department, University of Antwerp, Universiteitsplein 1, B2610,
Antwerp, Belgium