Design, Synthesis, and Biological Insights of Half Sandwich Ruthenium-Arene Schiff Base Complexes: Molecular Docking and DFT

Ruthenium complexes are gaining attention for their promising roles as chemotherapeutic and antimicrobial agents. In this study, three half sandwich organoruthenium(II) complexes, [(eta 6-p-cymene)Ru(L1)Cl]Cl [M1], [(eta 6-p-cymene)Ru(L2)Cl]Cl [M2], and [(eta 6-p-cymene)Ru(L3)Cl]Cl [M3], have been synthesized by reacting [{(eta 6-p-cymene)RuCl}2(mu-Cl)2] with Schiff base ligands namely.N-(Salicylidene)-4-toluidine (L1), N-(Salicylidene)-4-aminobenzoic acid (L2), and N-(Salicylidene)-2-hydroxyaniline (L3). These complexes have been characterized by elemental analysis, UV-vis., FTIR, multinuclear NMR and ESI-MS spectroscopic methods. Computational analysis for these complex cations suggests distorted octahedral geometry around Ru(II) that is coordinated to azomethine nitrogen and phenoxide centers of the Schiff base ligand in bidentate mode, chloro and p-cymene ligand in eta 6-mode. Further, molecular electrostatic potential (MEP) values calculations have been performed to gain insights into the electronic properties and stability. Molecular docking studies reveal strong interaction between M1 and penicillin-binding protein-2 (PBP2), thereby highlighting its potential as an antibacterial agent against resistant bacteria. M1 exhibits over 90% inhibition against Mycobacterium tuberculosis at 12.5 mu M and showcases potential anticancer activity against Human cervical cancer cells (SiHa). This study underscores the structural, computational, and biological significance of such class of ruthenium(II) complexes for biomedical applications.