Zinc(II) complexes of carboxamide derivatives: Crystal structures and interaction with calf thymus DNA

Synthesis, structural characterization, and theoretical analysis of novel zinc(ii) schiff base complexes with halogen and hydrogen bonding interactions

In this article, we present the synthesis and characterization of three zinc(ii) complexes, [ZnII(HL1)2] (1), [ZnII(HL2)2]·2H2O (2) and [ZnII(HL3)2] (3), with three tridentate Schiff base ligands, H2L1, H2L2, and H2L3. The structures of the complexes were confirmed by single-crystal X-ray diffraction analysis. DFT calculations were performed to gain insights into the self-assembly of the complexes in their solid-state structures. Complex 1 exhibits dual halogen-bonding interactions (Br⋯Br and Br⋯O) in its solid-state structure, which have been thoroughly investigated through molecular electrostatic potential (MEP) surface calculations, alongside QTAIM and NCIPlot analyses. Furthermore, complex 2 features a fascinating hydrogen-bonding network involving lattice water molecules, which serves to link the [ZnII(HL2)2] units into a one-dimensional supramolecular polymer. This network has been meticulously examined using QTAIM and NCIplot analyses, allowing for an estimation of the hydrogen bond strengths. The significance of H-bonds and CH⋯π interactions in complex 3 was investigated, as these interactions are crucial for the formation of infinite 1D chains in the solid state.

Synthesis and characterization of nano crystallite carboxamide-based iron(III) complexes: SOD mimetic activity, antibacterial and anticancer activity and molecular docking study

Three carboxamide-based ligands and their iron(III) complexes were prepared and structurally characterized. Analytical, thermal and mass spectra measurements showed a 1:1 stoichiometric (M:L) of the synthesized iron(III) complexes. The distorted octahedral geometry of the present iron(III) complexes was assigned based on the results of spectroscopy and magnetometry. Processing of X-ray diffraction data for powder samples by the software Expo 2014 confirmed the octahedral geometry of the three iron(III) complexes. Electrochemical properties of the present iron(III) complexes were studied by cyclic voltammetric measurements. The present iron(III) complexes exhibit SOD like activity with IC50 values of 16.45, 15.24 and 9.70 μM. The drive forces (-λ or ΔG°) controlling these biocatalytic reactions were determined and correlated with catalytic activity. The proposed catalytic mechanistic implications for the conversion of O2•- to H2O2 and H2O were discussed. The antimicrobial activity has been studied in vitro against G(+) and G(-) pathogenic bacteria. The in vitro anticancer activity of the carboxamide-based ligands and their iron(III) complexes against human Hepatocellular carcinoma (HepG-2) cell lines was examined. The obtained results demonstrated the potent anticancer activity of iron(III) complexes with increased safety on normal cells compared to cisplatin. Molecular docking calculations confirmed the experimental findings of the antibacterial and anticancer activities of both free ligands and their iron(III) chelates.Communicated by Ramaswamy H. Sarma.

Benzimidazole–acid hydrazide Schiff–Mannich combo ligands enable nano–molar detection of Zn2+ via fluorescence turn–on mode from semi–aqueous medium, HuH–7 cells, and plants

Herein, we have synthesized two unsymmetrical and dipodal Schiff–Mannich combo ligands, benzoic acid (3–benzoimidazol–1–ylmethyl–2–hydroxy–5–methyl–benzylidene)–hydrazide (H2BBH) and the hydroxyl analogue, 2–hydroxy–benzoic acid (3–benzoimidazol–1–ylmethyl–2–hydroxy–5–methyl–benzylidene)–hydrazide (H3BSH) for selective detection of Zn2+ in semi–aqueous...