Neuartige zwitterionische λ5-Spirosilicate: Synthese und Kristallstruktur von Bis[l,2-benzoldiolato(2 – )][2-(dimethylammonio)phenyl]silicat sowie Synthese von Bis[2,3-naphthalindiolato(2 – )][2-(dimethylammonio)phenyl]silicat-Hemiacetonitril-Solvat / Novel Zwitterionic λ5-Spirosilicates: Synthesis and Crystal Structure of Bis[1,2-benzenediolato(2–)][2-(dimethylammonio)phenyl]silicate and Synthesis of Bis[2,3-naphthalenediolato(2–)][2-(dimethylammonio)phenyl]silicate Hemiacetonitrile Solvate