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

Abstract

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) Å3, 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(F 2) = 0.0358, wR(F 2) = 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)_6^{3-}, has a distorted icosahedral geometry.