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

## TL;DR

Researchers created stable ruthenium nanoparticles using a uracil-based ligand, which show selective antimicrobial activity against Staphylococcus aureus.

## Contribution

The first use of a zwitterionic uracil-derived NHC precursor for synthesizing Ru nanoparticles with 100% atom economy.

## Key findings

- Ru@ura-NHC nanoparticles were synthesized using a zwitterionic uracil-6-yl-imidazolium betaine as the NHC precursor.
- The neutral form of the uracil-based NHC coordinates more effectively to the Ru surface than the zwitterionic form.
- The nanoparticles show selective antimicrobial activity against Staphylococcus aureus with minimal off-target effects.

## Abstract

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.