1. Chair of Chemical Technology of Materials SynthesisJulius‐Maximilians‐University Würzburg Röntgenring 11 D97070 Würzburg Germany
2. Fraunhofer Institute for Silicate Research ISC Neunerplatz 2 D97082 Würzburg Germany
3. Institute of Inorganic ChemistryJulius‐Maximilians‐University Würzburg Am Hubland 97074 Würzburg Germany