Three azido-, alk/phenoxido- and acetato-bridged tetranuclear nickel complexes featuring defective double-cubane

摘要

Three new tetranuclear nickel(II) complexes of general formula [Ni _4(L)_2(N_3)_2(CH_3COO) _2(CH)_3O)_2]_2·xCH _3OH·yH_2O (HL = HL~1, HL~2 and HL~3; x = 0, y = 1 for 1; x = 2, y = 0 for 2 and x = 2, y = 4 for 3) were synthesized and characterized by single crystal X-ray diffraction and magnetic measurements. Single crystal X-ray studies reveal that all three complexes exhibit similar tetranuclear face-shared defective double-cubane structure, having azido-, alk/phenoxido- and acetato-bridges. Magnetic susceptibility measurements on the complexes in the range of 300-2 K indicate ferromagnetic coupling between the metal ions. The slightly different magnetic behaviors observed are probably caused by subtle structural differences between the respective [Ni_4O_4N_2] cores induced by ligand variation.