Solvothermal Syntheses, Crystal Structures and Magnetic Properties of Two Nickel Cubane-Type Cluster Complexes

Two novel tetra-nuclear clusters, [Ni-4(HL1)(3)(mu(3)-O)(H2O)(3)]center dot C2H5OH center dot H2O (1) and [Ni-4(HL2)(3) (mu(3)-O)(H2O)(3)]center dot 3H(2)O (2, H3L1 = (E)-2-((2-hydroxy-3-methoxybenzylidene)amino)-2-methylpropane- 1,3-diol; H3L2 = (E)-2-((5-bromo-2-hydroxybenzylidene)amino)-2-methylpropane-1,3-diol), were synthesized by a solvothermal method and characterized by elemental analysis, thermogravimetric analysis, infrared spectroscopy, and singlecrystal X-ray diffractometry. The complexes 1 and 2 revealed similar cubane-type [Ni4O4] structures, which were connected alternately by three hydroxyls from different Schiff base ligands and one mu(3)-O. Hirshfeld surface analysis revealed that H center dot center dot center dot H, C center dot center dot center dot H, and O center dot center dot center dot H interactions were the main intermolecular interactions. Magnetic properties reveal that the {Ni4O4} cores display dominant ferromagnetic interactions from the nature of the binding modes through mu(3)-O.