A series of complexes with a [Mn8O8]8+ saddle-like core: Facile synthesis, crystal structure and magnetic property

Three manganese complexes formulated as [CeIVMn8IIIO8(O2CMe)12(H2O)4]·4H2O (1·4H2O), [CeIVMn8IIIO8(O2CMe)12(py)3(H2O)]·6.5H2O (2·6.5H2O), [CeIVMn8IIIO8(O2CMe)12(bzd)2(H2O)2]·10H2O(3·10H2O) (where py = pyridine, bzd = benzimidazole), have been synthesized and characterized by elemental analysis, IR and single-crystal X-ray diffraction analyses. Complexes 1–3 all consist of a central Ce4+ ion surrounded by a nonplanar, saddle-like [Mn8O8]8+ loop via eight μ3O2− ions, and peripheral ligation is provided by twelve acetate groups, four water molecules for complex 1, twelve acetate groups, three pyridines and one water molecule for complex 2, twelve acetate groups, two benzimidazoles and two water molecules for complex 3. Variable-temperature magnetic susceptibility measurements reveal the ground-state spin (S) values of 8 for complexes 1 and 2, which are half of the analogous complex previously reported. An explanation for this difference is also included in the text.