Solid-state synthesis, characterization and antimicrobial studies of Ni (II), Co (II) and Cu (II) complexes 1-(4-nitrophenyl)imino]methyl)naphthalen-2-ol

Abstract

Mechanochemicals synthesis has now been considered as a field of considerable interest for sustainable and green chemistry as a result of its safety, cost effectiveness and high yield. Ni (II), Co (II) and Cu (II) Metal complexes of 1-(4-nitrophenyl)imino]methyl)naphthalen-2-ol have been synthesized. The complexes were synthesized by grinding in an agate mortar with pestle. The complexes were characterized for their decomposition temperature, solubility test, magnetic susceptility, conductivity measurement and their surface functional groups were investigated using the Fourier Transform Infrared Spectroscopy (FTIR). The FTIR spectra of the free ligand showed a band at 1629cm^-1 which is assigned to the stretching vibration of the azomethine. The down shifts of this band (1629cm^-1) to lower frequencies in the spectra of the metal (II) complexes indicate complexation. The job’s method of continuous variation suggested a 1:2 metal-ligand ratio all the Ni (II), Co (II) and Cu (II) complexes. The lower conductivity measurement values (43, 34 and 29 Ohm^-1cm²mol^-1) revealed the non electrolytic nature of the complexes. The Schiff base and its complexes have been tested for antimicrobial activity against bacterial isolates (Staphylococcus aureus and Escherichia coli) and fungal isolates (Mucor sp and Aspergillus flavus). All the complexes exhibited appreciable activity on all the isolates.

Keywords: Antimicrobial, Metal Complexes, Schiff base, Solid-state, 2-Hydroxy-1 napthaldehyde