1. Institute of Inorganic Chemistry, University of Zürich, Winterthurerstrasse 190, 8057 Zürich (Switzerland), Fax: (+41) 44‐635‐6802
2. Department of Bioinorganic and Biomedical Chemistry, Faculty of Chemistry, University of Wrocław, F. Joliot Curie 14, 50‐383 Wrocław (Poland)
3. Department of Chemistry, Inorganic Chemistry, University of Basel, Spitalstrasse 51, 4056 Basel (Switzerland)