Crystallographic disorder in mixed-valent dioxo-bridged Mn^III,IV complexes. [Mn₂O₂(bpy)₄][Ce(NO₃)₆].5H₂O

The structure of tetrakis(2,2′-bipyridine)di-μ-oxo-di­manganese­(3+) hexa­nitratocerate(3−) pentahydrate, [Mn₂O₂(bpy)₄]­[Ce(NO₃)₆].5H₂O, is described; M_r = 1368.88, monoclinic, C2/c, a = 12.940 (3), b = 18.060 (2), c = 22.54 (1) Å, β = 96.29 (2)°, V = 5237 (3) ų, T = 132 K, Z = 4, F(000) = 2752, D_x = 1.736 Mg m⁻³, λ(Mo Kα) = 0.71073 Å, μ = 1.429 mm⁻¹, R(F²) = 0.0358, wR(F²) = 0.0783 for 4877 reflections with I > 2σ(I). The cation does not have crystallographically distinguishable Mn atoms. An analysis of the atomic displacement ellipsoids and Mn—N bond distortions has been used to develop a model for the disorder in this type of mixed-valent complex. The anion, Ce(NO₃), has a distorted icosahedral geometry.