LAUSR

Co(II), Ni(II) and Cu(II) complexes of an ionic liquid-supported Schiff base 1-{2-[(2-hydroxy-5-bromobenzylidene)amino]ethyl}-3-ethylimidazolium tetrafluoroborate were synthesized and characterized by various analytical and spectroscopic methods such as elemental analysis, UV-Visible, FT-IR,$$^{1}$$1H NMR, ESI MS, molar conductance and magnetic susceptibility measurements. Based on the spectral studies, tetra coordinated geometry was proposed for the complexes and molar conductance of the complexes revealed their electrolytic nature. The synthesized Schiff base and its complexes were evaluated for in vitro antibacterial activities against Gram positive and Gram negative bacteria. The complexes along with the Schiff base showed very significant biological activity against the tested bacteria.GRAPHICAL ABSTRACTCo(II), Ni(II) and Cu(II) complexes bearing an ionic liquid-supported Schiff base 1-{2-[(2-hydroxy-5-bromobenzylidene)amino]ethyl}-3-ethylimidazolium tetrafluoroborate as ligand, is reported. The spectral and magnetic susceptibility measurements suggest that the bidentate ligand coordinates to the central metal ion through the azomethine nitrogen and phenolic oxygen atoms, yielding a square planar complex.