K10[Co4O9], ein neues Oxocobaltat(II) mit oligomerem Anion

K₁₀Co₄O₉], a New Oligooxocobaltate(II) For the first time dark-red single crystals of K₁₀Co₄O₉] were obtained by heating mixtures of KO_0.48 and CdO (molar ratio 2.7:1) in closed Co-cylinders at 450°C during 73 d. Structure solution and refinement (four-circle diffractometer data, Mo Kα , 2 996 out of 2 996 I_o(hkl), R = 5.20%, R_w = 3.03%) confirm the space-group P1 and show structural relationship with Na₁₀Co₄O₉] 2]. The lattice constants are a = 667.84(5) pm, b = 917.91(9) pm, c = 908.49(7) pm, α = 119.400(7)°, β = 90.851(7)°, γ = 110.260(6)°, Z = 1 . (powder data (Guinier-Simon), standard deviations in parentheses) MAPLE calculations are made and a comparative survey of MAPLE values of oxocobaltates(II) is given.