Antibacterial and ct-DNA binding studies of new synthesized ruthenium (III) hydroxamate complexes: Design, synthesis, DFT calculations and in-vitro study

•New Ru(III) hydroxamate complexes have been synthesized from different hydroxamic acid derivatives.•The synthesized complexes have been confirmed by various analytical and spectroscopic tools.•In-vitro biological screening of the synthesized Ru(III) complexes against ct-DNA.•Antibacterial activities have been evaluated using the agar well diffusion method.•Frontier molecular orbital energies and global reactivity parameters have been calculated by performing computational DFT studies.•Whole library of synthesized complexes was found active against different pathogenic strains with variable potential. Ruthenium (III) complexes (1–5) with general composition [Ru(L1–4)3] and [Ru(HL5)3Cl3] where L1 = benzohydroximato (1), L2 = salicylhydroximato (2), L3 = acetohydroximato (3), L4 = hydroxyureato (4), HL 5 = N‑hydroxy-N-phenylbenzamide (5) were synthesized by reacting RuCl3·3H2O with respective hydroxamic acids in 1:3 molar ratio . The complexes were characterized using various techniques including ruthenium metal analysis, elemental analysis, UV–Vis, FT-IR, NMR (1H and 13C), and mass spectrometry. Antibacterial activity of the complexes was evaluated using the agar well diffusion method against ten pathogenic strains. The complexes showed significant inhibition zones and were more active than their corresponding ligands. DNA binding studies indicated intercalative binding mode, with hypochromism and red shift observed. Computational and structural parameters were determined using Frontier Molecular Orbital (FMO) energies and Density Functional Theory (DFT) calculations. The complexes demonstrated favorable molecular geometry, chemical reactivity, and biological activity.