Synthesis, spectroscopic and structural characterization, and antimicrobial studies of metal complexes of a new hexadentate Schiff base ligand. Spectrophotometric determination of Fe(III) in water samples using a recovery test

Synthesis, Spectroscopic Characterization, Molecular Docking, and Evaluation of Antibacterial Potential of Transition Metal Complexes Obtained Using Triazole Chelating Ligand

Mononuclear chelates of Ni(II), Co(II), Fe(III), Cd(II), and Cu(II) derived from triazole novel tridentate ligands were prepared and characterized by different spectroscopic methods. The metal to ligand ratio was 1 : 2, which was revealed by elemental analysis. All the complexes were electrolytic in nature as suggested by the conductivity measurements. IR pointed out that the coordination of the triazole ligand toward the metal ions was carried out through N amino and S thiophenolic atoms. The complexes were found to have octahedral geometry, and their thermal stability was also studied. The XRD spectrum of Co(II) and Fe(III) complexes concluded their crystalline structure. The parent ligand and its chelates were investigated for antimicrobial potential. Bioassay of all triazole complexes showed increased activity as compared to that of the ligand. The complexes having Ni(II), Co(II), and Cu(II) ions as metal center exhibited superior antibacterial activity in opposition to Gram-positive (B. subtilis and S. pyogenes) and Gram-negative (E. coli and P. vulgaris) bacterium as compared to standard.

Transition Metal Complexes of Mixed Bioligands: Synthesis, Characterization, DFT Modeling, and Applications

Divalent transition metal complexes [MGlu-Arg (H2O)]H2O and [MGlu-Arg (H2O)]H2O, where M = Co, Ni, Cu, and Zn, Glu = glutamic acid, and Arg = L-arginine, are prepared and characterized using different techniques. DFT and TD-DFT modelling validated and interpreted some experimental results. Weight loss technique reveals efficient corrosion inhibition action of these complexes towards aluminum metal at different temperatures. Our results point to corrosion inhibition through chemical adsorption on the aluminum surface. Additionally, a facile calcination of Co and Cu complexes at 550°C yields nanosized oxides of Co3O4, CoO, and CuO crystalline phases. The complexes show remarkable biological activities towards pathogenic bacteria and fungi. Moreover, in vitro anticancer activity evaluation of these complexes is achieved against hepatocellular carcinoma (HepG-2). The results are correlated with molecular descriptors such as chemical potential and hardness obtained from the frontier orbitals.

Coordination behavior of new bis Schiff base ligand derived from 2-furan carboxaldehyde and propane-1,3-diamine. Spectroscopic, thermal, anticancer and antibacterial activity studies

Novel bis Schiff base ligand, [N1,N3-bis(furan-2-ylmethylene)propane-1,3-diamine], was prepared by the condensation of furan-2-carboxaldehyde with propane-1,3-diamine. Its conformational changes on complexation with transition metal ions [Co(II), Ni(II), Cu(II), Mn(II), Cd(II), Zn(II) and Fe(III)] have been studied on the basis of elemental analysis, conductivity measurements, spectral (infrared, (1)H NMR, electronic), magnetic and thermogravimetric studies. The conductance data of the complexes revealed their electrolytic nature suggesting them as 1:2 (for bivalent metal ions) and 1:3 (for Fe(III) ion) electrolytes. The complexes were found to have octahedral geometry based on magnetic moment and solid reflectance measurements. Thermal analysis data revealed the decomposition of the complexes in successive steps with the removal of anions, coordinated water and bis Schiff base ligand. The thermodynamic parameters were calculated using Coats-Redfern equation. The Anticancer screening studies were performed on human colorectal cancer (HCT), hepatic cancer (HepG2) and breast cancer (MCF-7) cell lines. The antimicrobial activity of all the compounds was studied against Gram negative (Escherichia coli and Proteus vulgaris) and Gram positive (Bacillus vulgaris and Staphylococcus pyogones) bacteria. It was observed that the coordination of metal ion has a pronounced effect on the microbial activities of the bis Schiff base ligand. All the metal complexes have shown higher antimicrobial effect than the free bis Schiff base ligand.