1. Department of Chemistry, SLU, Box 7015, SE-750 07 Uppsala, Sweden, Moscow State Academy of Fine Chemical Technology, Pr. Vernadskogo 86, 117571 Moscow, Russia, Inorganic Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden, Department of Chemistry, Moscow State University, 119991 Moscow, Russia, and Max-Plank Institute for Chemical Physics of Solids, 01187-Dresden, Germany