Die Kristallstruktur von Ag2Ge2O5: Eine neuartige Gerüststruktur von Ge2O52−

Crystal Structure of Ag₂Ge₂O₅: A New Ge₂O₅^2? Network Structure Ag₂Ge₂O₅ was prepared from the binary oxides at high O₂ pressures. Single crystal X-ray diffraction work indicated monoclinic symmetry (P2₁/c; a = 1101.3(2); b = 1006.3(1); c = 1221.9(3) pm; ß = 94.6(1)°). The structure was determined by direct methods (3372 independent structure factors) and refined to a conventional R value of 0.084. A new Ge₂O₅^2? network structure was found with germanium coordinated octahedrally (­d(Ge—O) = 188,7 pm) and tetrahedrally (­d(Ge—O) = 175,9 pm), in equal proportions, by oxygen. The polyhedra share vertices and edges, thus forming a three dimensional channel system, which is occupied by Ag⁺ ions. The shortest Ag—Ag distance of 284 pm, like the pale yellow colour of the compound, indicates Ag⁺—Ag⁺ interaction.