K6[Mn2O6] und K6[Fe2 O6] - ein Vergleich

K₆Mn₂O₆] and K₆Fe₂O₆] - a Comparison K₆Mn₂O₆] has been prepared (dark-red single crystals). The structure (a = 8.88₆, b = 6.76₀, c = 11.39₄ Å, γ = 132.1°, space group P2₁, Z = 2, 1151 symmetry independent reflections hk0–hk9, R = 0.051) shows Al₂Cl₆-like anions Mn₂O₆]^6?. By unit-cell transformation to the monoclinic setting P2₁/a (a = 6.76₀, b = 11.39₄, c = 6.63₈ Å, β = 96,9°) the structural similarity to K₆Fe₂O₆] becomes evident. The Madelung Part of Lattice Energy, MAPLE, is calculated.