Darstellung und Kristallstruktur der Cäsium-Selenidogermanate(IV) Cs4Ge4Se10 · 2CH3OH und Cs4Ge2Se8 / Preparation and Crystal Structure of the Cesium Selenidogerm anates(IV) Cs4Ge4Se10 · 2CH3OH and Cs4Ge2Se8

Abstract

Methanolothermal reaction of Cs2CO3 with Ge and Se at 190 °C yields Cs4Ge4Se10 · 2 CH3OH and Cs4Ge2Se8, the structures of which have been determined by X-ray structural analysis. The anion [Ge4Se10]4 in Cs4Ge4Se10)·2 CH3OH displays an adamantane-like structure in which four GeSe4 tetrahedra are linked via joint vertices. In con­trast Cs4Ge2Se8 contains the novel dinuclear anion [Ge2Se8]4-, the first example of a selenidogermanate(IV) exhibiting Se2 bridging units. Two GeSe4 tetrahedra are linked in this anion through Se-Se bonds to yield a six-membered ring, which displays a chair conformation and crystallographic C2h symmetry.