Tethering (Arene)Ru(II) Acylpyrazolones Decorated with Long Aliphatic Chains to Polystyrene Surfaces Provides Potent Antibacterial Plastics

• Main Authors: Corrado Di Nicola, Fabio Marchetti, Riccardo Pettinari, Alessia Tombesi, Claudio Pettinari, Iolanda Grappasonni, Paul J. Dyson, Stefania Scuri
• Format: Article
• Language: English
• Published: MDPI AG 2020-01-01
• Series: Materials
• Subjects: bioorganometallic chemistry; ruthenium(ii) complexes; acylpyrazolones; nanoformulation; tethering on polyethylene and polystyrene; antibacterial composite materials
• Online Access: https://www.mdpi.com/1996-1944/13/3/526

The acylpyrazolone proligands HQ^R (HQ^R in general, in detail: HQ^Cy = 1-phenyl-3-methyl-4-carbonylcyclohexyl-5-pyrazolone, 4-C(O)-phenyl, HQ^Ph = 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone, HQ^C17 = 1-phenyl-3-methyl-4-stearoyl-5-pyrazolone, HQ^C17,Ph = 1-phenyl-3-stearyl-4-benzoyl-5-pyrazolone) were synthesized and reacted with (arene)Ru(II) acceptors affording complexes [(arene)Ru(Q^R)Cl] (arene = cymene (cym) or hexamethylbenzene (hmb)). The complexes were characterized by elemental analyses, thermogravimetric analysis-Differntial Thermal Analysis (TGA-DTA), IR spectroscopy, ESI-MS and ¹H, and ¹³C NMR spectroscopy. Complexes [(arene)Ru(Q^R)Cl] where Q^R = Q^C17 and Q^C17,Ph, due to the long aliphatic chain in the ligand, afford nanometric dispersions in methanol via self-assembly into micellar aggregates of dimensions 50&#8722;200 nm. The antibacterial activity of the complexes was established against <i>Escherichia coli</i> and <i>Staphylococcus aureus</i>, those containing the ligands with a long aliphatic chain being the most effective. The complexes were immobilized on polystyrene by a simple procedure, and the resulting composite materials showed to be very effective against <i>E. coli</i> and <i>S. aureus</i>.