On the Non‐Metallicity of 2.2 nm Au246(SR)80 Nanoclusters
Abstract
The transition from molecular to plasmonic behaviour in metal nanoparticles with increasing size remains a central question in nanoscience. We report that the giant 246‐gold‐atom nanocluster (2.2 nm in gold core diameter) protected by 80 thiolate ligands is surprisingly non‐metallic based on UV/Vis and femtosecond transient absorption spectroscopy as well as electrochemical measurements. Specifically, the Au246 nanocluster exhibits multiple excitonic peaks in transient absorption spectra and electron dynamics independent of the pump power, which are in contrast to the behaviour of metallic gold nanoparticles. Moreover, a prominent oscillatory feature with frequency of 0.5 THz can be observed in almost all the probe wavelengths. The phase and amplitude analysis of the oscillation suggests that it arises from the wavepacket motion on the ground state potential energy surface, which also indicates the presence of a small band‐gap and thus non‐metallic or molecular‐like behaviour.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Nov 22, 2017
- Source ID
- 10.1002/anie.201709095
Entities
People
- Chenjie Zeng
- Gangli Wang
- Jonathan W. Padelford
- Matthew Y. Sfeir
- Meng Zhou
- Rongchao Jin
- Tatsuya Higaki
- Yongbo Song
Organizations
- Air Force Office of Scientific Research
- Brookhaven National Laboratory
- Carnegie Mellon University
- Georgia State University
- Office of Basic Energy Sciences