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Novel series of Co(II), Ni(II) and Cu(II) transition metal complexes were synthesized from the Schiff base ligands HL1–HL4 derived from 2-amino-6- nitrobenzothiazole with various aromatic aldehydes, i.e., 4-methylbenzaldehyde, 4- ethylbenzaldehyde, 2-hydroxybenzaldehyde and 4-hydroxybenzaldehyde, respectively. The ligands HL1–HL4 and their metal (II) complexes were characterized by atomic absorption spectroscopy (AAS), magnetic susceptibility and molar conductance measurements, and UV–Vis, FT-IR and NMR spectroscopic techniques. The spectroscopic studies revealed that the complexes of HL1–HL3 coordinated in an octahedral environment and L4 in square planar/tetrahedral geometry. The ligands HL1–HL4 and their metal(II) complexes were screened for their antimicrobial activities against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans. The results suggest that the complexes of HL4 possess greater inhibition activity towards C. albicans. The nonlinear optics (NLO) activities of ligands HL1–HL4 were determined. The obtained results showed that ligands HL1 and HL2 have greater second harmonic generation (SHG) efficiency than HL3and HL4.

In this research article, the synthesis, structural characterization, and biological, DNA binding and anticancer properties of pyrimidine incorporated Schiff base ligand L and its [CuL2](ClO4)2 (1) and [ZnL2](ClO4)2 (2) complexes are reported. The isolated complexes 1 and 2 have significant antibacterial and antifungal properties, greater than those of ligand L. The interaction between protein and L were analyzed by an in silico method. The intercalative binding of the prepared compounds was proved from electronic absorption, fluorometric, cyclic voltammetric and viscometric methods. The calculated binding parameters such as, Kb (2.65×103, L; 7.74×103, 1 and 2.99×103, 2); Ksv (3.30×103, L; 4.31×103, 1 and 3.89×103, 2), and Kapp (2.15×105, L; 3.30×105, 1 and 2.82×105, 2) indicted that complex 1 has better interaction ability than L and complex 2. The in vitro anticancer properties of L, and complexes 1 and 2 against human cancer (MCF-7, HeLa and HEp-2) and normal (NHDF) cell lines were determined by the MTT assay method. The obtained results designated that complexes 1 and 2 exhibited substantial anticancer activity against the cancer cell lines, better than that of L.

AbstractA novel azo-based benzimidazole Schiff base ligand (FDSBI) was synthesized by the condensation reaction of 2-aminobenzimidazole with 4-fluorodiazenyl-salicylaldehyde. The ligand and its metal complexes were studied by elemental analysis, spectral analysis, and magnetic susceptibility measurement. The absorption spectra of the complexes evidence octahedral geometry. The structural properties of the Schiff base and its metal complexes were also proved by the treatment of density functional theory (DFT) calculation. Thermogravimetric analysis proved the coordinated and lattice water molecules. Cyclic voltammetry technique has been used to study the redox behavior of the copper (II) complex. The in vitro antibacterial and antifungal activities of the Schiff base and its coordinated compounds were screened against bacterial species (Staphylococcus aureus, Salmonella typhi, Escherichia coli, Bacillus subtilis) and Fungi (Candida albicans, Aspergillus niger) using well diffusion method. The obtained results have suggested that the metal complexes showed significant biological activity than ligand. The in vitro antioxidant activity of both the ligand and its metal (II) complexes was assessed through the utilization of the DPPH stable free radical. The result shows that the ligand possesses better antioxidant properties than metal (II) complexes. The second harmonic generation efficiency was analyzed for the ligand, demonstrating its potential application in nonlinear optical material. [ABSTRACT FROM AUTHOR]

Hybrid matrices (epoxidized of ethylene–propylene–diene monomer (eEPDM) -g- aminopropyltriethoxysilane (APTES)/hydroxyl terminated polydimethylsiloxane (HTPDMS)/polyurethane (PU)) were developed based on eEPDM with 3-APTES coupling agent and varying weight percentages (0.75, 1.50, 2.25, and 3.00 wt%) of PU prepolymer as coreactant using 7.5 wt% of HTPDMS as chain extender using suitable experimental conditions. The formation of hybrid matrices and their structure were characterized by Fourier transform infrared (FTIR). The thermal and morphological properties of the hybrid matrices were analyzed using differential scanning calorimetry and scanning electron microscope, respectively. Mechanical properties (tensile strength, elongation at break (%), Young's modulus, and hardness) were characterized as per ASTM standards. Data resulted from mechanical studies, it was noticed that the incorporation of 3-APTES, HTPDMS, and PU into eEPDM has improved the elongation at break (%) and lowered the values of tensile strength, Young's modulus, and hardness according to the percentage concentration. Morphological studies indicate the presence of heterogeneous morphology. Data obtained from different studies, it suggested that the hybrid matrices developed in the present work can be used as cable insulates for high-performance industrial and engineering applications. [ABSTRACT FROM AUTHOR]