1. Institute of Physical Chemistry of the Romanian Academy, Coordination Chemistry Laboratory, Bucharest, Spl. Independentei nr. 202, 060021-Bucharest Romania
2. University of Bucharest, Faculty of Chemistry, Inorganic Chemistry Laboratory, Str. Dumbrava Rosie nr. 23, 020464-Bucharest, Romania
3. National Institute for Laser, Plasma and Radiation Physics, Laboratory of Solid-State Quantum Electronics, P.O. Box MG-36, Magurele, 077125, Romania