Synthesis, Crystal Structure, and Magnetic Properties of Polynuclear Salamo Ni(II) Complexes

Abstract

Four distinct polynuclear Ni(II) complexes, namely [Ni 2 L 2 (py) 2 ] (1), [Ni 3 L 2 (μ 3 -OAc) 2 ]•4CH 3 CN (2), [Ni 4 L 2 (μ 2 -OAc) 2 (μ 3 -OMe) 2 (H 2 O) 2 ]•MeOH (3), and [Ni 7 L 3 (μ 3 -OMe) 2 (μ 3 -OH) 6 (MeOH) 6 ] (4), have been synthesized and characterized based on the salamo Schiff base ligand H 2 L. Ultraviolet−visible titration experiments and time-dependent density functional theory calculations elucidated that different reaction conditions (solvents and the metal−ligand molar ratio) result in the formation of these polynuclear structures. Magnetic investigations revealed the presence of intramolecular ferromagnetic coupling between Ni(II) centers in complexes 2−4.