Synthesis, Characterization and Antimicrobial Activity of Mixed Schiff Base Ligand Complexes of Co(II), Ni(II), Cu(II) and Zn(II)

Abstract

The mixed ligand complexes of Co(II), Ni(II), Cu(II) and Zn(II) with Schiff bases N-(2-hydroxy-1-naphthylidene)-4-methylaniline (L 1 H) and N-(2-hydroxybenzylidene)-2,3-dimethylaniline (L 2 H) have been synthesized and characterized. The resulting complexes were characterized by elemental analysis, thermogravimetric analysis, magnetic moment measurements, conductivity measurements, 1 H NMR, IR, UV-visible and ESR spectral studies. The Schiff bases acts as bidentate monobasic ligands, coordinating through deprotonated phenolic oxygen and azomethine nitrogen atoms. The complexes are non-electrolytic in DMSO. The presence of the two coordinated water molecules in these complexes was indicated by IR spectra and thermogravimetric analysis of the complexes. From the analytical and spectral data the stoichiometry of these complexes have been found to be [M(L 1 )(L 2 )(H 2 O) 2 ] {where M = Co(II) , Ni(II), Cu(II) and Zn(II)}. It is found that Co(II), Ni(II), Cu(II) and Zn(II) complexes exhibited octahedral geometry. The antimicrobial activities of ligands and their mixed ligand complexes were screened by disc diffusion method. It is found that the metal complexes have higher antimicrobial activity than the free ligand.

Synthesis, Characterization and Antimicrobial Activity of Schiff Base (<i>E</i>)-<i>N</i>-(4-(2-Hydroxybenzylideneamino) Phenylsulfonyl) Acetamide Metal Complexes

“…This is further confirmed by the appearance of a new band characteristic of νC=N [20] [21]. As shown in Figure 3.…”

Synthesis, structural characterization and thermal properties of a new copper(II) one-dimensional coordination polymer based on bridgingN,N′-bis(2-hydroxybenzylidene)-2,2-dimethylpropane-1,3-diamine and dicyanamide ligands

“…Free H 2 L-DM shows a medium intensity band at 1279 cm À1 due to the phenolate (C-O) group which is shifted to a higher region at around 1358 cm À1 in the spectrum of the complex, indicating that it is the deprotonated ligand (L-DM 2À ) that is coordinated to the Cu II centre. These bands prove that the shifts are due to coordination of H 2 L-DM to the Cu II ion through azomethine N and phenolate O atoms (Mapari et al, 2011;Canpolat & Kaya, 2005). The dca ion has been observed to coordinate to metal cations in a variety of modes (see Scheme 1), which can be terminal or bridging.…”

New zinc(II) complexes of the Non-steroidal Anti-Inflammatory Drug (indomethacin) and various nitrogen donor ligands. Synthesis, characterization and biological activity

“…Many compounds possess modified pharmacological potentials when administered in the form of metal based compounds. Of the metal ions commonly used are cobalt, copper and zinc because of forming low molecular weight complexes and therefore, prove to be more beneficial against several diseases [32][33][34]. Carmen Sharaby have studied the effect of metallation on the antimicrobial activity of Schiff base namely 2-thiophene carboxaldehyde-sulfametrole.…”