Some New Zinc Halide Complexes of N2O2-Schiff Base: Synthesis, Thermal, Antimicrobial, Antioxidant, Anticancer and Burn Wound Healing Effects.

A series of novel zinc(II) complexes derived from a tetradentate N2O2-Schiff base ligand were synthesized using zinc halide and pseudohalide salts with the general formula ZnLX2 (X = Cl-, Br-, I-, N3 -, SCN-). The resulting compounds were thoroughly characterized by a range of spectroscopic and physicochemical techniques. Additionally, nanostructured zinc complexes such as ZnLBr2 and ZnLI2 were synthesized via an ultrasound-assisted approach, with ZnLI2 subsequently utilized as a precursor for the fabrication of ZnO nanoparticles. The nanostructures were confirmed by scanning electron microscopy (SEM), EDX, and x-ray diffraction (XRD) analyses. Thermal decomposition studies of the ligand and its zinc complexes revealed two- to three-step degradation processes, for which key thermokinetic parameters (E*, ΔS*, ΔH*, A, and ΔG*) were determined. From a biological standpoint, the synthesized compounds displayed potent antimicrobial activity against selected Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Pseudomonas aeruginosa and Escherichia coli) bacterial strains, as well as fungal pathogens (Aspergillus oryzae and Candida albicans). DNA cleavage assays further confirmed the nucleolytic potential of these complexes. Selected compounds demonstrated noteworthy cytotoxic effects against the PC3 human prostate cancer cell line, substantiating their anticancer capabilities. Antioxidant properties were evaluated using DPPH (2,2-diphenyl-1-picrylhydrazyl) and FRAP (ferric reducing antioxidant power) assays, exhibiting promising radical-scavenging activity. Notably, the ligand and ZnLI2 complex also exhibited significant efficacy in promoting burn wound healing, highlighting their therapeutic potential in both infectious and regenerative medicine.