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

Four distinct polynuclear Ni(II) complexes, namely [Ni2L2(py)2] (1), [Ni3L2(μ3-OAc)2]·4CH3CN (2), [Ni4L2(μ2-OAc)2(μ3-OMe)2(H2O)2]·MeOH (3), and [Ni7L3(μ3-OMe)2(μ3-OH)6(MeOH)6] (4), have been synthesized and characterized based on the salamo Schiff base ligand H2L. 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.