Ein Natrium‐Oxocobaltat(II)‐Hydroxid: Na5[CoO3]OH ≡ Na10[CoO3]{[CoO3](OH)2}

A Sodium‐Oxocobaltate(II)‐Hydroxide: Na₅[CoO₃]OH ≡ Na₁₀[CoO₃]{[CoO₃](OH)₂} Na₁₀[CoO₃]{[CoO₃](OH)₂} has been obtained from a redox reaction between cobalt metal and CdO in the presence of NaOH and Na₂O at 600 °C (21 d) as red single crystals. The structure has been determined from single crystal data (IPDS‐data, Pnma, Z = 4, a = 988.5(1) pm, b = 1013.9(2) pm, c = 1186.3(2) pm, wR2 = 0.079). Furthermore IR data and aspects of the Madelung part of the lattice energy are presented.