Synthesis, structure, and magnetism of a novel series of trinuclear nickel(II) clusters

Five novel trinuclear nickel(II) clusters were successfully synthesized, namely Ni-3(fshz)(2)(L)(4)center dot n(sol) (H(3)fshz = N-formylsalicylhydrazide; L = pyridine, n = 0, 1; L = 4-methylpyridine, n = 1, sol = CH3CN, 2; L = 4-ethylpyridine, n = 2, sol = CH3OH, 3; L = 4-vinylpyridine, n = 1, sol = CH3OH, 4; and L = 2,6-pyridinedimethanol, n = 2, sol = CH3OH, 5). Single-crystal X-ray diffraction revealed that the metallic skeletons of 1-5 were built by three Ni(II) ions, two fshz(3-) units, and four auxiliary ligands. The coordination geometry of the Ni(II) ions in 1-5 are followed in two modes: square-planar and/or octahedral. Magnetic studies showed that 1-5 displayed intermolecular antiferromagnetic behavior and all the square-planar Ni(II) ions were diamagnetic as certified. Moreover, 1-4 presented easy-axis anisotropy with D = -4.02, -5.31, -4.82, and -3.65 cm(-1), respectively, while 5 presented easy-plane anisotropy (D = 1106 cm(-1)) due to the different coordination mode.

Automated summary

Five novel trinuclear nickel(II) clusters were synthesized and characterized. The clusters displayed intermolecular antiferromagnetic behavior, with the square-planar Ni(II) ions being diamagnetic. Different anisotropy features were observed, including easy-axis anisotropy for 1-4 and easy-plane anisotropy for 5.