Synthesis, Characterization, Computational Evaluation, CO-Releasing Properties, and Molecular Docking Interactions of New [Mn(CO)₃(bpy)L]PF₆-Type Molecules

Designing CO-releasing molecules, which store, transport, and release carbon monoxide in the target tissue, has accelerated since scientists revealed that carbon monoxide is one of the transmitters and could be effective in treatment procedures. The most important candidates for this task are metal carbonyl complexes. In this study, [Mn-(CO)₃(bpy)-L]-PF₆-type metal carbonyl complexes were synthesized and characterized and the CO-releasing activities of these molecules were investigated. In addition, the optimization and theoretical analysis of the molecules were performed with DFT/TDDFT-based calculation methods. DFT computations at the B3LYP/6-311G-(d,p)/LANL2DZ level were performed to assign vibrational modes and NMR shifts following geometry optimization and confirmation. Moreover, NBO analyses were performed to predict the important electronic interaction that occurred in complexes: the results implied that the biggest contribution could come from the resonance interactions. FMOs analyses indicated that the 2e could be a softer (η= 1.511 eV) and is less stabilized complex via back-donation (Δε_{back‑donat.} = -0.378 eV). Additionally, the interactions of the molecules with HSA, BSA, and DNA were investigated with molecular docking methods, and the binding properties of the manganese complexes were analyzed in vitro with UV-vis spectroscopy against BSA and DNA by the Benesi-Hildebrand method.