A new series of Schiff base Ni(II)4 cubanes: Evaluation of magnetic coupling via carboxylate bridges

Abstract The Schiff base ligand H2L has been synthesized by condensation of 2-aminophenol with 3-methyl-1-phenyl-4-formylpyrazol-5-one and reaction between Ni(OOCR3)2, R = H in 1, –CH3 2, Cl 3, yielded three new tetranuclear Ni(II) complexes. complexes have characterized elemental analysis, IR- ES-MS spectroscopy. Their structures as well structure were determined single-crystal X-ray diffraction. Compounds 1–3 possesses cubane-like containing [Ni4L4(R3COO)2]2? complex anions, which are charge balanced two triethyl ammonium cations. Furthermore, the crystal cubane compound trichloroacetate bridging ligands, is reported for first time. Variable temperature magnetic susceptibility measurements revealed interplay ferromagnetic antiferromagnetic exchange compounds 1–3, interactions enhanced introducing carboxylate groups. DFT calculations supported analysis data.