Related Experiment Video
Updated: Sep 29, 2025
08:21
Fabrication of Periodic Gold Nanocup Arrays Using Colloidal Lithography
Published on: September 2, 2017
7.3K
Understanding nascent plasmons and metallic bonding in atomically precise gold nanoclusters.
Xiangsha Du1, Zhongyu Liu1, Tatsuya Higaki1
1Department of Chemistry, Carnegie Mellon University Pittsburgh Pennsylvania 15213 USA rongchao@andrew.cmu.edu.
Chemical Science
|March 21, 2022
Summary
Metallic bonding in gold nanoclusters (NCs) is intriguing. Cryogenic spectroscopy reveals plasmon excitation persists from metallic to insulating states, suggesting nonthermal electron-gas formation.
Area of Science:
- Nanochemistry
- Materials Science
- Physical Chemistry
Background:
- The metallic bond and plasmon excitation in nanomaterials are of significant scientific interest.
- Atomically precise nanoclusters (NCs) represent a frontier in nanochemistry.
- Understanding the evolution of bonding states in NCs is crucial.
Purpose of the Study:
- To investigate the electronic and optical properties of nascent metallic gold nanoclusters (NCs) at cryogenic temperatures.
- To explore the origin of electron-gas formation and plasmon excitation in Au NCs.
- To elucidate the transition from covalent to metallic bonding in NCs.
Main Methods:
- Synthesis of thiolate-protected Au279(SR)84 and Au333(SR)79 nanoclusters.
- Cryogenic optical spectroscopy down to 2.5 K.
- Analysis of plasmon resonances and electronic states.
Main Results:
- Au NCs exhibited distinct plasmon resonances at room temperature, with a small electronic gap.
- Plasmon excitation remained unaffected by the transition from metallic to insulating states at cryogenic temperatures.
- A nonthermal origin for electron-gas formation was indicated.
Conclusions:
- The study provides insights into the nascent metallic state and bonding evolution in gold nanoclusters.
- Electronic screening plays a key role in the formation of metallic states.
- Plasmon birth is linked to concerted excitonic transitions.
