1. Institute for Inorganic Chemistry, University of Erlangen-Nürnberg, Egerlandstrasse 1, 91058 Erlangen, Germany, Department of Inorganic Chemistry, Jagiellonian University, Ingardena 3, 30-060 Krakow, Poland, and Max-Planck-Institut für Strahlenchemie, Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany