Solvatochromic, spectroscopic, DFT calculations, antimicrobial and docking studies of new Fe(III), Co(II), and Ni(II) chelates containing 1,2,4-triazine

) and multiple empirical functions, including the Bilot-Kawski, Lippert-Mataga, Bakhshiev, and Kawski-Chamma-Viallet models. A notable increase in dipole moment upon excitation suggests enhanced stabilization of the excited state in polar solvents, particularly involving n-π* transitions. Density Functional Theory (DFT) calculations, performed using the B3LYP/GENECP method with a 6-311G(d, p) basis set for non-metal atoms and SDD for metal atoms, supported experimental data and provided insights into optimized structural parameters. Further computational analyses included molecular electrostatic potential (MEP) mapping and nonlinear optical (NLO) property evaluation, revealing charge distribution and optical characteristics. The antimicrobial activity of the complexes was tested against a panel of Gram-positive, Gram-negative bacteria, and fungi, showing promising efficacy. Finally, molecular docking studies were conducted to investigate the binding interactions of the chelates with the FabH-CoA enzyme complex (PDB ID: 1HNJ), providing insight into their potential as bioactive agents.