1. Department of Chemistry, University of Cyprus, P.O. Box 20537, 1678 Nicosia, Cyprus, Department of Materials Science and Technology, University of Crete, P.O. Box 2208, 710 03 Heraklion, Crete, Greece, Institute of Electronic Structure and Laser, Foundation for Research and TechnologyHellas, P.O. Box 1527, 711 10 Heraklion, Crete, Greece, and Cyprus Institute of Neurology and Genetics, P.O. Box 23462, 1683 Nicosia, Cyprus