New Insights on the Bonding Properties of BCC-like Au38S2(SR)20 Nanoclusters from X‑ray Absorption Spectroscopy

• Published in: Journal of physical chemistry. C Vol. 122; no. 39; pp. 22776 - 22782
• Main Authors: Yang, Rui, Morris, David J, Higaki, Tatsuya, Ward, Matthew J, Jin, Rongchao, Zhang, Peng
• Format: Journal Article
• Language: English; Japanese
• Published: American Chemical Society 04.10.2018
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/acs.jpcc.8b07551

X-ray spectroscopy techniques have been known as a useful tool for the study of structure and bonding properties of gold nanoclusters (NCs), and such information has been proven valuable to advance their fundamental research and applications. Herein, we report new insights on the bonding properties of body-centered cubic (BCC)-like Au38S2(SR)20 nanoclusters from Au L3-edge X-ray absorption spectroscopy. The first-derivative X-ray absorption near edge structure (XANES) is shown as a sensitive tool to detect the surface structure and bonding properties of the Au NCs. On the basis of the XANES experimental results and quantum calculations, Au–Au bond distance from the NC surface sites is found to be directly related to the early region of the Au L3-edge XANES spectral features. Extended X-ray absorption fine structure analysis shows significantly shorter Au–Au bond distances in BCC-like Au38S2(SR)20 in comparison with those in bi-icosahedral like Au38(SR)24 NCs. The contraction of Au–Au bonding upon solvation suggests the importance of thiolate ligand type in influencing the NC bonding properties.