1. Centre/Department of Physics; University of Minho, Campus de Gualtar; 4710-057 Braga Portugal
2. Centre/Department of Chemistry; University of Minho, Campus de Gualtar; 4710-057 Braga Portugal
3. Laboratorio de Química Inorgánica; Universidad de Córdoba, Edificio Maria Curie, Campis de Rabanales; 14071 Córdoba Spain