Methanolothermale Synthese und Kristallstruktur von Diselenido- und Ditelluridogermanaten(IV) der Alkalimetalle K – Cs / M ethanolothermal Synthesis and Crystal Structure of Diselenido- and Ditelluridogerm anates(IV) of the Alkali Metals K – Cs

Abstract

Methanolothermal reaction of M2CO3 (M = K, Rb) with Ge and Se yields respectively the diselenidogermanates(IV) K2GeSe4 and Rb2GeSe4, both of which contain chain anions 1 ∞[GeSe4 2-] in which GeSe4 tetrahedra are linked via Se-Se bonds. A similar structural principle is found in the ditelluridogermanates(IV) Rb2GeTe4 and Cs2GeTe4, prepared by reaction of M2CO3 (M = Rb, Cs) with Ge and Te in methanol at temperatures of respectively 200 and 160 °C. The effect of cation size on the chain conformation is discussed. Rb4Ge4Se10 · CH3OH, which is formed together with Rb2GeSe4, exhibits isolated anions [Ge4Se10]4- with an adamantane-like structure.