Synthesis and X-ray crystal structures of trinuclear nickel(II) complexes derived from schiff bases and acetate ligands with biological activity

Abstract

The reactions of Ni(OAc)2 2H2O with Schiff base ligands 5-bromo-2-((cyclopentylimino)methyl)phenol (HL1) and 5-bromo-2-(((2-(isopropylamino)ethyl)imino)methyl)phenol (HL2) in methanol afforded two discrete trinuclear complexes [Ni3(L1)2(μ2-η1:η1-OAc)2(DMF)2(BrSal)2] (1) and [Ni3(L2)2(μ2-η1:η1-OAc)2(μ2-η2:η1-OAc)2] (2), where BrSal is the monoanionic form of 4-bromosalicylaldehyde. The complexes were characterized by elemental analysis, IR and UV-Vis spectroscopy. The crystal structures of the complexes have been determined by X-ray crystallography. In both complexes, the nickel atoms are in octahedral coordination geometries. The L1 ligand coordinates to the nickel atoms through the phenolate O and imino N atoms, and the L2 ligand coordinates to the nickel atoms through the phenolate O, imino N and amino N atoms. The antimicrobial activities of the complexes were assayed.