1. Department of Physics of Semiconductor Compounds “Sergiu Radauţan”, Institute of Applied Physics, Kishinev MD-2028, Moldova
2. Department of Molecular Magnetic Nanomaterials, Institute of Problems of Chemical Physics, Chernogolovka, Moscow Region 142432, Russia
3. Departement für Chemie und Biochemie, Universität Bern, Freiestrasse 3, Bern CH-3012, Switzerland