1. Institute of Inorganic and Analytical Chemistry, University of Jena, August‐Bebel‐Strasse 2, 07743 Jena, Germany, Fax: +49‐3641‐442716
2. Present address: Ludwig‐Maximilians‐Universität München, Department Chemie, Butenandtstraße 5–13 (Haus D), 81377 München, Germany