Tunable Aminooxy-Functionalized Monolayer-Protected Gold Clusters for Non-Polar or Aqueous Oximation Reactions

Area of Science:

• Nanotechnology
• Organic Chemistry
• Surface Chemistry

Background:

• Aminooxy groups exhibit chemoselective reactions with carbonyl compounds, enabling diverse applications.
• Gold nanoparticles (Au MPCs) are widely used in various fields due to their unique properties.

Purpose of the Study:

• To develop a novel aminooxy 'click chemistry' approach for functionalizing gold nanoparticles.
• To synthesize and characterize aminooxy thiol (AOT) ligands for Au MPCs.
• To demonstrate the versatility of the functionalized Au MPCs in oximation reactions.

Main Methods:

• Synthesis of a trifunctional amine-containing aminooxy alkane thiol ligand (AOT).
• Ligand exchange protocol to coat AOT onto hexanethiolate-capped Au MPCs, forming mixed monolayer protected clusters (MMPCs).
• Characterization of Au(C6S)(AOT) MMPCs and evaluation of their reactivity in oximation reactions with aldehydes.

Main Results:

• Successfully synthesized organic-soluble AOT ligands and Au(C6S)(AOT) MMPCs.
• Demonstrated efficient oximation reactions between the functionalized Au MPCs and various aldehydes.
• Showcased the ability to switch solubility characteristics of the MMPCs via amine protonation.

Conclusions:

• Aminooxy click chemistry provides a facile and versatile method for functionalizing gold nanoparticles.
• The synthesized Au(C6S)(AOT) MMPCs are suitable for a range of applications involving aldehyde-containing molecules.
• Amine protonation offers a tunable mechanism for controlling nanoparticle solubility.