Synergistic enhancement of antimicrobial, anticancer, and catalytic activities in novel Cu(II) and ZrO(II) heteroleptic complexes featuring a benzohydrazide schiff base and 1,10-phenanthroline.

Abstract

This work describes the construction and comprehensive characterization of heteroleptic metal chelates (CuBA-Phen and ZrOBA-Phen) derived from N-(1-(pyridin-2-yl)ethylidene)benzohydrazide (BA) and 1,10-phenanthroline (phen) with Cu(II) and ZrO(II) ions, respectively, which were characterized by alternative techniques, in addition to density functional theory (DFT) calculations. Conductivity data indicated that the ZrO(II)-complex behaves as a 1:1 electrolyte, whereas the Cu(II) complex is a non-electrolyte. FT-IR analysis confirmed tridentate coordination of BA via CO, CN, and the pyridine nitrogen atom, while phen coordinated through its nitrogen donor centers. Spectral and magnetic studies suggested a square-pyramidal geometry for the ZrO(II)-complex and an octahedral geometry for the Cu(II) complex. Thermogravimetric analysis revealed initial loss of hydrated lattice and chloride ions, followed by ligand decomposition, allowing an estimation of the kinetic parameter of the activation energy (E*) and the thermodynamic activation parameters (ΔH+, ΔS+, and ΔG+). For the DFT calculations at the B3LYP level, a 6-311 G + + (d, p) basis set was used for C, H, Cl, N, and O atoms, and the basis set of LANL2DZ was employed for the metal center. The results provided insights into molecular geometry, HOMO and LUMO orbital energies, energy gaps, and electrostatic potential distribution. Biological evaluation demonstrated notable antimicrobial and antioxidant activities, along with promising cytotoxic effects against the cell lines of MCF-7 and HepG2 types. Investigations of DNA interaction indicated effective reactivity via intercalation or electrostatic modes. Molecular docking (MOE) supported favorable binding affinities toward selected receptors. Catalytic studies showed that CuBA-Phen exhibited superior efficiency in the oxidation of 1,2-cyclooctene, achieving 93% yield within 3 h compared to 84% for ZrOBA-Phen after 5 h, using acetonitrile and H₂O₂/TBHP as optimal conditions.