Robust, Highly Luminescent Au 13 Superatoms Protected by N-Heterocyclic Carbenes

• Published in: Journal of the American Chemical Society Vol. 141; no. 38; pp. 14997 - 15002
• Main Authors: Narouz, Mina R, Takano, Shinjiro, Lummis, Paul A, Levchenko, Tetyana I, Nazemi, Ali, Kaappa, Sami, Malola, Sami, Yousefalizadeh, Goonay, Calhoun, Larry A, Stamplecoskie, Kevin G, Häkkinen, Hannu, Tsukuda, Tatsuya, Crudden, Cathleen M
• Format: Journal Article
• Language: English
• Published: United States 25.09.2019
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/jacs.9b07854

Gold superatom nanoclusters stabilized entirely by N-heterocyclic carbenes (NHCs) and halides are reported. The reduction of well-defined NHC-Au-Cl complexes produces clusters comprised of an icosahedral Au core surrounded by a symmetrical arrangement of nine NHCs and three chlorides. X-ray crystallography shows that the clusters are characterized by multiple CH-π and π-π interactions, which rigidify the ligand and likely contribute to the exceptionally high photoluminescent quantum yields observed, up to 16.0%, which is significantly greater than that of the most luminescent ligand-protected Au superatom cluster. Density functional theory analysis suggests that clusters are 8-electron superatoms with a wide HOMO-LUMO energy gap of 2 eV. Consistent with this, the clusters have high stability relative to phosphine stabilized clusters.