Surface Engineering Assisted Size and Structure Modulation of Gold Nanoclusters by Ionic Liquid Cations

Area of Science:

• Nanomaterials Science
• Surface Chemistry
• Inorganic Chemistry

Background:

• Surface modification is a key factor influencing the properties of inorganic nanoparticles.
• Understanding molecular-level changes during surface modification is crucial for controlling nanoparticle synthesis.
• Atomically precise gold nanoclusters (Au NCs) offer unique opportunities to study these phenomena.

Purpose of the Study:

• To demonstrate how surface modification can control the size and structure of atomically precise gold nanoclusters (Au NCs).
• To elucidate the molecular mechanisms underlying size and structure control in Au NC synthesis.
• To explore the synergistic integration of gold nanoclusters and ionic liquids.

Main Methods:

• Utilizing π-π enhanced ion-pairing interactions between ionic liquid (IL) cations and gold(I)-thiolate complexes.
• Employing hydrophobic-hydrophobic interactions of IL cations to stabilize gold precursors.
• Controlling Au NC formation through IL cation structure/concentration, pH, and solvent polarity.

Main Results:

• Achieved selective stabilization of the Au⁰ core, enabling size and structure control of Au NCs.
• Demonstrated the production of small-sized Au NCs via reduction of stabilized Au^I -thiolate complexes.
• Successfully produced atomically precise Au NCs with tunable size, atomic packing, and surface chemistry.

Conclusions:

• Surface modification with ILs provides a facile route to synthesize size- and structure-controlled Au NCs.
• The study reveals molecular-level insights into surface modification-induced changes in Au NCs.
• This approach facilitates the integration of Au NC and IL functionalities for broader applications.