| 研究実績の概要 |
With the Kakenhi funds, we have made significant progress on the synthesis and characterization of novel nanoclusters. In addition, we have made strides to understanding their properties in terms of stability, interconversions and catalytic reactivity. These results are broken down by cluster type.
Building on the previous work, we strived to make a cluster in which the NHC ligand was the predominant ligand, not the ancillary ligand. To achieve this, we investigated the reduction of well-defined NHC－Au－Cl complexes. This produced clusters composed of an icosahedral Au13 core (similar to the abovementioned Au11) which is an 8-electron superatom. This synthetic success allowed us to study the effect of the structure of NHC ligands, including electronic configuration and steric effects on size, structure, and properties of gold nanoclusters. In particular, X-ray crystallography shows that the clusters with benzyl and naphthyl wingtips are characterized by multiple CH－π and π－π interactions, which rigidify the ligand shell 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 gold clusters. Subsequent work in our group has identified derivatives that are highly active in photocatalytic reactions.
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