Ein neuartiges Polyoxocobaltat(II)‐Anion in Rb2Co2O3

A New Polyoxocobaltate(II) Anion in Rb₂Co₂O₃ Rb₂Co₂O₃ was prepared via the azide/nitrate route. Mixtures of the precursors Co₃O₄, RbN₃ and RbNO₃ in the molar ratios 6:17:1 were heated in a special regime up to 450 °C and annealed at this temperature for 50 h in silver crucibles. Single crystals have been grown by subsequent annealing of prepared powder at 450 °C for 500 h in silver crucibles, which were sealed in glass ampoules under dried Ar. According to the X‐ray analysis of the crystal structure (Pnma, Z = 8, 11.729(2), 6.058 (1), 8.004(1) Å) cobalt is trigonal planar coordinated by oxygen atoms. The CoO₃‐units share through all corners and build up an infinite two‐dimensional Co₂O₃‐network.