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

Advanced synthesis, comprehensive characterization, and potent cytotoxicity of 2,6-Bis(2-aminophenylimino)methyl)-4-methoxyphenol and its binuclear copper(II) complex

The imine base and Cu2+ precursors were combined using magnetic stirring to formulate the Cu2+ complexes. The formation of the imine base was confirmed by electronic and vibrational spectra, proton NMR, LC-mass spectrometry, and computational studies, which also optimized the final structure. The Cu2+ complexes were characterized using electronic and vibrational spectra, magnetic susceptibility, molar conductivity, a variable temperature magnetometer, and ESR spectroscopy. Cyclic voltammetry revealed electron transfer from Cu2+ to Cu+ within the complex. The in vitro tumour activity of the Cu2+ complexes and imine base were evaluated on the A431 cell line using the MTT assay. DFT studies validated the structural stability of the imine base. The antiferromagnetic behaviour observed at low temperatures suggests that these Cu2+ complexes could be useful in heavy magnetic materials. Due to their electron transfer properties, Cu2+ complexes also hold potential for use in electroplating systems and sensors. The complexes exhibited high efficacy on the cell line, aligning with clinical objectives. The Cu2+ complexes are represented as [MLR], where M is the metal, L is the imine base, and R = [C₆H₅COO] or R = [C₆H₄COO(NH₂)].

Exploring superior nonlinear optical properties of copper complexes with π-conjugated ligands: experimental and theoretical investigation

This study explores the nonlinear optical (NLO) properties of two synthesized copper complexes, {[Cu(dmp)2(H2O)]·(PA)2} (complex 1) and {[Cu(dmp)2]·(PA)} (complex 2), where dmp represents 2,9-dimethyl-1,10-phenanthroline (neocuproine) and PA refers to picric acid. Employing both experimental and theoretical approaches, we comprehensively analyzed their NLO properties. Experimentally, third-order NLO parameters were determined using the Z-scan technique with a 520 nm continuous-wave diode laser, yielding values of nonlinear refractive index (n 2), nonlinear absorption coefficient (β), and third-order nonlinear optical susceptibility (χ (3)) on the order of 10-7 cm2 W-1, 10-3 cm W-1, and 10-6 esu, respectively. These findings underscore their significant optical nonlinearity and suitability for intensity-dependent NLO applications, as evidenced by their high values of negative refractive index. Density Functional Theory (DFT) investigations were performed at the M062X/(6-31G(d,p)/LanL2DZ)) level to evaluate key reactivity descriptors, including polarizability, hyperpolarizability, and dipole moment, which align with the experimental results. Conceptual DFT analysis reveals that complex 1 is more stable, while complex 2 exhibits higher reactivity. The strong hyperpolarizability and remarkable third-order NLO properties of these copper complexes demonstrate their potential for advanced photonic and optoelectronic applications.

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.

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)].

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

A new mononuclear NiII complex with bis-(pyridin-2-yl)amine (dpyam) and benzoate (benz), [Ni(C7H5O2)2(C10H9N3)], crystallizes in the monoclinic space group P21/c. The NiII 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.