Novel Nickel (II), Copper (II) and Cobalt (II) Complexes of Schiff Bases A, D and E: Preparation, Identification, Analytical and Electrochemical Survey

Computational and experimental studies of Metallo organic framework on human epidermal cell line and anticancer potential

The pentadentate ligand and the precursors were combined to form complexes by green approach. The ligand formation was confirmed by UV-Vis, FT-IR, ¹H-NMR, and LC-MS. The optimised stable structure was obtained by molecular simulation studies and the complexes were interpreted by conductivity measurements, UV-Vis, FT-IR, magnetic susceptibility, VSM, and ESR spectral studies. The redox nature of the complexes was investigated by cyclic voltammetry. The cyclic voltammogram shows complexes exhibited single electron transfer from Cu⁺²/Cu⁺¹. Complexes and penta-dentate ligand were screened for in vitro cytotoxicity by MTT assay method on A431 skin cancer cell line. The ligand structural stability and biological activity were confirmed by theoretical computational studies. The magnetic behaviour showed antiferromagnetic properties at low temperature. The complexes were used as high bar magnets. Similarly, the redox behaviour showed that the complexes could be used in electroplating techniques and sensors. Clinical application revealed that the complexes had effective cytotoxicity. From the data obtained, the complexes were in the form [MLR], where L was the penta-dentate ligand and R = [C₆H₅COO] & R = [C₆H₄COO (OH)].

Synthesis, characterization and utility of a series of novel copper(II) complexes as excellent surface disinfectants against nosocomial infections

Nosocomial infections are among the major public health concerns, especially during the ongoing Covid19 pandemic. There is a great demand for novel chemical agents that are capable of killing specific pathogens or augmenting the efficiency of existing disinfectants. Herein, we report the synthesis and comprehensive characterization (through FT-IR, HR-MS, SEM, TGA-DSC, CV, UV and SCXRD analyses) of six novel copper(ii) complexes, [CuL(4X-An)] (5a-5d), [CuL(An)] (5e), and [CuL(benzhydrylamine)] (5f), and their evaluation as anti-microbial agents against WHO priority pathogens, confirming their possible use in hospital settings. The compounds were synthesized with a Schiff base (H2L) obtained by the condensation reaction of 3-acetyl-6-methyl-2H-pyran-2,4(3H)-dione (DHA) and benzohydrazide and further addition of different p-substituted aniline (An) molecules. Single crystal structure analyses revealed that the aniline derivatives are isostructural to the copper atom in a square planar coordination, while the benzhydrylamine complex forms a dimer (5f), with a square pyramidal coordination geometry for the metal. Time-kill kinetics and reduced microbial recovery studies revealed excellent bactericidal action against Staphylococcus aureus and Enterococcus faecalis. Particularly, the novel compound 5f significantly reduced microbial recovery compared to ethanol-based sanitisers. In fact, addition of 5f to 70% ethanol remarkably synergized the killing with >6-log reduction in microbial burden. Overall, our novel compounds would increase the disinfection efficacy in hospitals and industries, thereby improving the efficiency and minimizing the risk of infections.

Crystal structure and Hirshfeld surface analysis of bis-(benzoato-κ2 O,O')[bis-(pyridin-2-yl-κN)amine]nickel(II)

A new mononuclear Ni^II complex with bis-(pyridin-2-yl)amine (dpyam) and benzoate (benz), [Ni(C₇H₅O₂)₂(C₁₀H₉N₃)], crystallizes in the monoclinic space group P2₁/c. The Ni^II ion adopts a cis-distorted octa-hedral geometry with an [NiN₂O₄] chromophore. In the crystal, the complex mol-ecules are linked together into a one-dimensional chain by symmetry-related π-π stacking inter-actions [centroid-to-centroid distance = 3.7257 (17) Å], along with N-H⋯O and C-H⋯O hydrogen bonds. The crystal packing is further stabilized by C-H⋯π inter-actions, which were investigated by Hirshfeld surface analysis.