Crystallographic disorder in mixed-valent dioxo-bridged MnIII,IV complexes.
The structure of tetrakis(2,2'-bipyridine)di-µ-oxo-dimanganese(3+) hexanitratocerate(3-) pentahydrate, [Mn(2)O(2)(bpy)(4)][Ce(NO(3))(6)].5H(2)O, is described; M(r) = 1368.88, monoclinic, C2/c, a = 12.940 (3), b = 18.060 (2), c = 22.54 (1) Å, beta = 96.29 (2) degrees, V = 5237 (3) Å(3), T = 132 K, Z = 4, F(000) = 2752, D(x) = 1.736 Mg m(-3), lambda(Mo Kalpha) = 0.71073 Å, µ = 1.429 mm(-1), R(F(2)) = 0.0358, wR(F(2)) = 0.0783 for 4877 reflections with I > 2sigma(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(NO(3))(6)(3-), has a distorted icosahedral geometry.
School of Chemistry, University of Hyderabad, Hyderabad 500046, India.
D
Ramalakshmi
MV
Rajasekharan