A new symmetrical nickel(II) complex with isothiocyanate coordination: synthesis, crystal structure, Hirshfeld surface analysis, DFT calculation and antibacterial activities

The metal salts KSCN, Ni(CH3COO)2·4H2O, and auxiliary ligand pyridine were added respectively to the salamo-like ligand H2L, and it is expected that the Ni(II) complex coordinated by H2L will be obtained. X-ray analysis of the obtained blue bulk single crystal revealed that the ligand H2L did not participate in the coordination, and a mononuclear Ni(II) complex [Ni(Py)4(NCS)2] contained four coordinated pyridine molecules was unexpectedly obtained, and characterized by IR, UV-Visible spectroscopy, and X-ray diffraction. The Ni(II) atom was surrounded by six N atoms, formed a slightly distorted octahedral geometry configuration. Hirshfeld surfaces analyses were performed to determine the various interactions presented in the molecule. DFT calculations were also conducted. In antimicrobial tests, the Ni(II) complex exhibited better inhibition of Escherichia coli relative to Staphylococcus aureus.