Synthesis, Characterization and Bio-Potential Activities of Co(II) and Ni(II) Complexes with O and N Donor Mixed Ligands

Abstract

The synthesis and characterization of Co(II) and Ni(II) mixed ligand complexes are derived from isoniazid, 9-fluorenoneandoxalate. The metal complexes were characterized on the basis of elemental analysis, IR, UV-visible, CV, PXRD, and molar conductance analytical data, viz., all the metal complexes were suggested in an octahedral geometry, respectively. The mixed ligand complexes are formed in the 1:1:2:1 (M:L1:L2:L3) ratios, as found from the elemental analyses, and originate to have the formula [M(L1)(L2)2(L3)]. Where M = Co(II), Ni(II), L1 = isoniazid,L2= 9-fluorenone, and L3 = oxalate. The molar conductance data reveals that the complexes are non-electrolytes. The cyclic voltammogram of the Co(II) complex revealed that the quasi-reversible single electron transfer process and Ni(II) complex corresponding to a one-electron transfer process were observed during controlled potential electrolysis. IR spectra show that the ligands are coordinated to the metal ions through N and O donor sites of isoniazid-N, 9-fluorenone-O and oxalate-O. Magnetic moment values and UV-visible spectra were used to infer the coordinating of the geometrics of these complexes found to be octahedral. The PXRD patterns suggest that all the complexes are crystalline phases. The metal chelates have been screened for antimicrobial, antioxidant and anti-inflammatory activities, and our findings have been reported, explained and compared with some known antibiotics.

Synthesis, Characterization,Computational Studies and Antimicrobial activity evaluation of Mixed ligand‐Metal complexes of selected thiosemicarbazones

“…The zone of inhibition indicates the effect of the complex on the microorganism under identical experimental conditions. [59] Table 4 summarizes the antibacterial activity in terms of the zone of inhibition. L1 exhibited significant activity against S. pyogenesand P. aeruginosa andwas found to be inactive against E.coli.…”

“…Gram-positive bacteria possess a thick cell wall having many layers of peptidoglycan and teichoic acids, whereas Gram-negative bacteria have comparatively thin cell walls and the peptidoglycans layer is surrounded by a second lipid membrane having lipopolysaccharides and lipoproteins. [59] The formation of the inhibition zone around each disc was measured, and the results were recorded in the form of inhibition zones as a function of diameter (mm). The zone of inhibition indicates the effect of the complex on the microorganism under identical experimental conditions.…”

“…The antibacterial activity was however low as compared to the standard drug, but enhancement in activity was observed as comparedto the uncoordinated ligand.The inhibitory action of the complexes may also be influenced by the release of the metal ion or the formation of reactive oxygen species (ROS) formed in the solution. [62] The complexes can adhere to the negatively charged bacterial cell wall through electrostatic force of attraction, damage the cell wall and then bind to bacterial proteins and nucleic acids, resulting in cellular deformation and viability loss. It can be proposed that complexes having antibacterial activity may destroy the microorganisms or prevent microbial reproduction by blocking their active sites.…”

“…The difference in the cell wall is another factor which may lead to a difference in antibacterial activity. Gram‐positive bacteria possess a thick cell wall having many layers of peptidoglycan and teichoic acids, whereas Gram‐negative bacteria have comparatively thin cell walls and the peptidoglycans layer is surrounded by a second lipid membrane having lipopolysaccharides and lipoproteins [59] . The formation of the inhibition zone around each disc was measured, and the results were recorded in the form of inhibition zones as a function of diameter (mm).…”

Antimicrobial and Bioinformatic Modelling Studies of Isatin Mixed Ligand and Some Ternary Chelates

“…[21] The current research focuses on the synthesis and characterization of mixed ligand complexes having N and O donor atoms as their structures have crucial role in biological process as their similarity to enzymes. [22,23] Ternary complexes of isatin (ISA) as primary ligand, N,N,N',N'-tetramethylethylene diamine (TMEDA) (N-containing ligand) as secondary ligand with some transition metal ions (Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II)) were prepared and completely characterized using various physico-chemical techniques. Another objective, is to study the effect of the ligands and their metal complexes as antimicrobial agents showing the impact of the presence of metal ions.…”