Ru Nanoparticles Ligated by an N-Heterocyclic Carbene Derived from Uracil Nucleoside as Selective Antimicrobial Agents

High Resolution Image Download MS PowerPoint Slide Metal nanoparticles (MNPs) effectively combat pathogens due to their nonspecific toxicity, reducing the chance of bacterial resistance. Natural-based stabilizing ligands enhance the stability and targeting of MNPs while minimizing toxicity to human cells. In this context, ura-NHC-stabilized Ru NPs ( Ru@ura-NHC ) have been successfully synthesized following an organometallic approach, employing Ru(COD)(COT) as the metal precursor and, for the first time, a zwitterionic uracil-6-yl-imidazolium betaine ( ura-zwt ) as the NHC precursor. The mesomeric properties of ura-zwt enabled its use as an air-stable NHC precursor for the one-pot synthesis of Ru@ura-NHC with 100% atom economy and without byproduct formation. A combined theoretical/experimental study was conducted to investigate the coordination of the uracil-based NHC onto the Ru surface, indicating that the coordination of the neutral form ( ura-NHC ) is preferred over the zwitterionic form ( ura-zwt ). Evaluation of the antimicrobial properties of Ru@ura-NHC revealed that the coated Ru NPs exhibit selective activity against Staphylococcus aureus, which is beneficial as it minimizes off-target effects and reduces selective pressure for resistance.