Crystallographic disorder in mixed-valent dioxo-bridged Mn < sup > III,IV < /sup > complexes. [Mn < inf > 2 < /inf > O < inf > 2 < /inf > (bpy) < inf > 4 < /inf > ]-[Ce(NO < inf > 3 < /inf > ) < inf > 6 < /inf > ].5H < inf > 2 < /inf > O

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; Mr = 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, Dx = 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)3-6, has a distorted icosahedral geometry.