1. Chair of Chemical Technology of Materials Synthesis Julius‐Maximilians‐University Würzburg Röntgenring 11 D‐97070 Würzburg Germany
2. Department of Chemistry and Pharmacy Inorganic Chemistry Friedrich‐Alexander University Erlangen‐Nürnberg (FAU) Egerlandstrasse 1 D‐91058 Erlangen Germany
3. Fraunhofer Institute for Silicate Research ISC Neunerplatz 2 D‐97082 Würzburg Germany