Synthese und Struktur von K2Au3, einer neuen Phase im System Kalium—Gold / Synthesis and Structure of K2Au3, a New Phase in the System Potassium —Gold

Au is obtained from the elements in a sealed Ta am poule as air-sensitive needles with a golden lustre. It crystallizes in the orthorhombic space group Immm with the lattice constants a = 487.5(2), b = 545.4(2), c - 1000.4(4) pm; Z = 2. The structure is com posed of planar layers of Au atoms at z = 0 and 0.5 and intercalated K atoms. The layers consist of triangles and hexagons with Au -Au distances between 268.8 and 280.2 pm. The K atoms have ten Au neighbours with distances from 334 to 389 pm.