Synthesis, structure and magnetic properties of a series of cubane-like clusters derived from Schiff base ligands

One new hexanuclear Cu(II) complex [Cu-4(L-1)(4)Na-2(ClO4)(H2O)](ClO4)(H2O)(0.5) (1) and two new tetranuclear Ni(II) complexes [Ni-4(L-2)(4)(CH3OH)(4)] (2), [Ni-4(o-vanillinate)(4)(mu(3)-N-3)(4)(CH3OH)(4)] (3) have been synthesized and structurally characterized. All the three complexes 1, 2, and 3 have been characterized by elemental analysis, FTIR, and single crystal X-ray diffraction studies. Single crystal X-ray diffraction studies reveal that all three complexes consist of a cubane core in which the four Cu(II)/Ni(II) centers in 1 and 2 are linked by mu(3)-alkoxo bridges and Ni(II) ions in 3 are linked by azido bridge in end-on fashion. The skeleton structures of the cubane cores are all distorted from the idealized cube and most show a further distortion. The variable-temperature (2-300 K) magnetic susceptibilities and magnetizations of the three compounds were measured. Variable-temperature magnetic susceptibility data exhibit dominant antiferrornagnetic interaction in complex 1 while ferromagnetic interactions in complexes 2 and 3. (C) 2014 Elsevier Ltd. All rights reserved.