Synthesis, spectral characterization, electrochemistry and catalytic activities of Cu(II) complexes of bifunctional tridentate Schiff bases containing ONO donors

Cu(II) and Mn(II) Anchored on Functionalized Mesoporous Silica with Schiff Bases: Effects of Supports and Metal-Ligand Interactions on Catalytic Activity

New series of Cu(II) and Mn(II) complexes with Schiff base ligands derived from 2-furylmethylketone (Met), 2-furaldehyde (Fur), and 2-hydroxyacetopheneone (Hyd) have been synthesized in situ on SBA-15-NH₂, MCM-48-NH₂, and MCM-41-NH₂ functionalized supports. The hybrid materials were characterized by X-ray diffraction, nitrogen adsorption-desorption, SEM and TEM microscopy, TG analysis, and AAS, FTIR, EPR, and XPS spectroscopies. Catalytic performances were tested in oxidation with the hydrogen peroxide of cyclohexene and of different aromatic and aliphatic alcohols (benzyl alcohol, 2-methylpropan-1-ol, and 1-buten-3-ol). The catalytic activity was correlated with the type of mesoporous silica support, ligand, and metal-ligand interactions. The best catalytic activity of all tested hybrid materials was obtained in the oxidation of cyclohexene on SBA-15-NH₂-MetMn as a heterogeneous catalyst. No leaching was evidenced for Cu and Mn complexes, and the Cu catalysts were more stable due to a more covalent interaction of the metallic ions with the immobilized ligands.

Synthesis, crystal structure, Hirshfeld surface analysis, energy frameworks and computational studies of Schiff base derivative

The compound (E)-ethyl 3-(2-(2,4-dinitrophenyl)hydrazono)butanoate (3) was synthesised and crystallized using ethanol as a solvent. The compound was characterized by ¹H NMR, and single crystal X-ray diffraction. The compound crystallizes in the monoclinic crystal system with the space group P2₁/c. The intermolecular interactions and the interaction energies responsible for the stabilization of the molecules were determined by Hirshfeld surface analysis and energy framework calculations. The structure of the compound was optimized by Density Functional Theory calculations and HOMO–LUMO energy gap was calculated. The non–covalent interactions were revealed by reduced density gradient analysis. The Mulliken atomic charges and natural atomic charges were calculated by density functional theory calculations. The reactive sites present in the molecule are shown by molecular electrostatic potential map. The inter and intra molecular charge transfer were investigated by NBO analysis.

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Crystal structure was confirmed by X-ray diffraction analysis and the atomic coordinates were optimized by DFT calculations.

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Hirshfeld surface analysis and energy frameworks calculations were carried out.

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HOMO - LUMO frontier molecular orbitals and molecular electrostatic potential were studied.

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Reduced density gradient (RDG), and topology analyses were performed.

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Natural bond orbital analysis was performed to study intramolecular charge transfer.

Dual sensing of methionine and aspartic acid in aqueous medium by a quinoline-based fluorescent probe

A quinoline-based Schiff base sensor, 6-methyl-2-oxo-1,2-dihydro-quinoline-3-carboxaldehyde-4(N)-phenylsemicarbazone (6MPS), has been developed for selective sensing of methionine and aspartic acid in aqueous medium through "on-off-on" type selective detection of copper ion. Fluorescence imaging of 6MPS, 6MPSC, 6MPSCN, 6MPSC-met, 6MPSCN-met, 6MPSC-asp and 6MPSCN-asp has been successfully demonstrated, in which the sensing probes 6MPSC-met, 6MPSCN-met, 6MPSC-asp and 6MPSCN-asp displayed bright green fluorescence in both in vitro and in vivo live cells.

Synthesis and spectral characterizations of water soluble Cu(ii) complexes containing N-heterocyclic chelates: cell-proliferation, antioxidant and nucleic acid/serum albumin interactions

Water soluble N-heterocyclic copper(ii) complexes were synthesized, characterized and studied their DNA/protein binding interactions, antioxidation and antiproliferative potentials. The complex 4 found to be better than other complexes.

A quinoline-based probe for effective and selective sensing of aspartic acid in aqueous medium: in vitro and in vivo live cell imaging

A highly sensitive and selective “on–off–on” chemosensor for aspartic acid in aqueous solution was established. In vitro live cell imaging against MCF 7 cells and in vivo imaging using C. elegans were successfully demonstrated.

Spectroscopic and structural studies of the Schiff base 3-methoxy-N-salicylidene-o-amino phenol complexes with some transition metal ions and their antibacterial, antifungal activities

Spectroscopic (IR, Raman, NMR, UV-visible, and ESR), and structural studies of the ligand 3-methoxy-N-salicylidene-o-amino phenol (H2L) and its synthesized complexes with some transition metal ions (Mn(II), Co(II), Ni(II)), Cu(II) and Zn(II)) were recorded and analyzed. The magnetic properties and thermal gravimetric analysis (TGA and DTA) were also measured for the complexes. The metal complexes were found to have The structural formula ML⋅H2O and the metal ions Mn(II), Co(II), Ni(II)) and Zn(II) were found to form tetrahedral complexes with the ligand whereas Cu(II) formed a square planar one. Antimicrobial activity of the ligand and its complexes were also investigated and discussed.

Cu(II) Complexes of Isoniazid Schiff Bases: DNA/BSA Binding and Cytotoxicity Studies on A549 Cell Line

A series of isonicotinoyl hydrazones have been synthesized via template method and were complexed to Cu(II). The ligands are coordinated to Cu(II) ion through the enolic oxygen and azomethine nitrogen resulting in a square planar geometry. The CT-DNA and bovine serum albumin binding propensities of the compounds were determined spectrophotometrically, the results of which indicate good binding propensity of complexes to DNA and BSA with high binding constant values. Furthermore, the compounds have been investigated for their cytotoxicities on A549 human lung cancer cell. Also the mode of cell death was examined employing various staining techniques and was found to be apoptotic.