1. Institut für Anorganische Chemie und Kristallographie; Fachbereich 2-Biologie/Chemie; Universität Bremen; Leobener Straße NW2 28359 Bremen Germany
2. Current address: Department of Chemistry; University of Alberta; Edmonton Alberta T6G 2G2 Canada
3. Centre of Supramolecular Organic and Organometallic Chemistry; Department of Chemistry, Faculty of Chemistry and Chemical Engineering; Babes-Bolyai University; 11 Arany Janos Street 400028 Cluj-Napoca Romania
4. Laboratory of Crystallography; University of Bayreuth; 95440 Bayreuth Germany
5. Institut für Experimentalphysik; Freie Universität Berlin; Arnimallee 14 14195 Berlin Germany