1. Department of Inorganic and Analytical Chemistry, University of Debrecen, H-4010 Debrecen Pf. 21, Hungary, Department of Chemistry, Inorganic Chemistry, The Royal Institute of Technology (KTH), S-100 44 Stockholm, Sweden, Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Leninsky Prospect 31, 119 991 Moscow, Russia, and IFM-Department of Chemistry, Linköping University, S-581 83 Linköping, Sweden