Nanospheric [M₂₀(OH)₁₂(maleate)₁₂(Me₂NH)₁₂]⁴⁺ Clusters (M = Co, Ni) with <i>O</i>_<i>h</i> Symmetry

Nanospheric hydroxo-bridged clusters of [M20(OH)12(maleate)12(Me2NH)12]­(BF4)3(OH)·nH2O (M = Co (1), Ni (2)) with Oh symmetry were afforded under hydrothermal condition with Co­(BF4)2·6H2O/Ni­(BF4)2·6H2O and fumaric acid in a DMF/EtOH mixed solvent. They are characterized by elemental analysis, IR, and X-ray diffraction. X-ray single crystal diffraction analyses show that these two complexes are isostructural containing an ideally cubic M8 core in that each two M atoms are doubly bridged at the edges by one OH– and one maleate, while these OH– and maleate groups are coordinated further by exterior identical 12 M atoms which construct a perfect M12 icosahedron to encapsulate the cubic core. To our knowledge, such large clusters with Oh symmetry are seldom. The variable-temperature magnetic susceptibility studies reveal that these two isostructures exhibit antiferromagnetic interactions.