1. Institute
of Inorganic Chemistry, Rheinische Friedrich-Wilhelms-Universität, Gerhard-Domagk-Straße 1, D-53121 Bonn, Germany
2. Institute
of Inorganic Chemistry, RWTH Aachen, Professor-Pirlet-Str. 1, D-52074 Aachen, Germany
3. Institute
of Inorganic Chemistry, Leibniz Universität Hannover, Callinstrasse
9, D-30167 Hannover, Germany
4. Chemistry
Department, University of Fribourg, Chemin du Musée 9, CH-1700 Fribourg, Switzerland