Oxydation intermetallischer Phasen: Na3[AuO2] aus NaAu und Na2O2

Oxidation of Intermetallic Phases: Na₃AuO₂] from NaAu and Na₂O₂ The hitherto unknown Na₃AuO₂] was prepared in transparent, colourless single crystals from NaAu and Na₂O₂1:1; sealed Ag-cylinder, 430°C, 6 d]. The crystal structure (P4₂/mnm); a = 970.5(1), c = 457.8(1) pm; Z = 4; four-circle diffractometer PW 1100, 333 out of 380 I₀(hkl), R = 7.0% and R_w = 6.5%] was solved. Like KAgO-Type there are planar rings Na₂Au₂O₄]^4?. Na(1) has the uncommon coordinations number 2 . The Effective Coordination Numbers, ECoN, the Mean Fictive Ionic Radii, MEFIR, and the Madelung Part of Lattice Energy, MAPLE, are calculated.