Imidazolium Ionic Liquid-Supported Schiff Base and Its Transition Metal Complexes: Synthesis, Physicochemical Characterization and Exploration of Antimicrobial Activities

Abstract

New Co(II), Ni(II) and Cu(II) metal complexes from an imidazolium ionic liquid supported Schiff base, 1-{2-(2-hydroxy-5-nitrobenzylideneamino)ethyl}-3-ethylimidazolium tetrafluoroborate were synthesized and characterized by different analytical and spectroscopic techniques such as elemental analysis (CHN analysis), UV-Visible, 1 H NMR, 13 C NMR, FT-IR, powder X-ray diffraction, mass-spectra, magnetic susceptibility measurements and molar conductance data. From these spectroscopic and analytical data, tetra coordinated 1:2 metal-ligand stoichiometry was suggested for the metal complexes. The molar conductance data of the complexes revealed their electrolytic nature (1:2). The synthesized complexes along with the ligand were screened for in vitro antibacterial applications against Gram-negative and Gram-positive bacteria to assess their inhibition potentials. The complexes were proved very effective against the tested organisms.

Synthesis, Spectral Characterization and Antimicrobial Evaluation of New Metal Complexes of Novel Schiff Base Derived from 4,6-dihydroxy-1,3-phenylenediethanone

“…groups and a singlet at 3.32-3.59 and 3.13-3.81 ppm was due to (-CH 2 ) groups [9][10] [11]. S cm − 1 mol − 1 for the Cu(II), Zn(II) and Cd(II) complexes, respectively, indicating their non -electrolytic nature [12].…”

“…The complexes were dissolved in DMF and their conductivity were measured at room temperature. The molar conductivity data were observed as 103, 104, 90, 115 and 62 S cm − 1 mol − 1 for Cr(III), Mn(II), Fe(III), Co(II) and Ni(II), respectively, indicating their electrolytic nature and as 35, 38 and 29 S cm − 1 mol − 1 for the Cu(II), Zn(II) and Cd(II) complexes, respectively, indicating their non -electrolytic nature [12].…”

Material Synthesis, Spectral, Optical and Antimicrobial Activity of Imidazolium Based Aldehydic Ionic Liquids: 1–Ethyl-3-methyl-2-(2-oxo-ethyl)-3H-imidazol-1-ium bromide (I) and 1-butyl-3-methyl-2-(2-oxo-ethyl)-3H-imidazol-1-ium chloride (II)

“…Due to the tenability and adaptability of ionic liquid behavior, ILs have been exploited for a variety of applications in academia and industry [1,3]. Due to their low vapor pressure and non-toxic ions, ILs are often safer solvents [4].…”

“…Due to the intrinsic magnetic, spectroscopic, and electrochemical characteristics of ionic liquids that depend on the confined metal ions, synthesized and characterized metals containing ionic liquids have high electrocatalytic activity [10,11]. The zinc (II) combination with imidazolium ionic liquid tag demonstrated effective DNA breakage and antifungal and antibacterial activity against gram-positive bacteria [4,11,12].…”