Dehydration of phenylboronic acid to boroxine catalyzed by Au(n) nanoclusters with atom packing core-shell structure.

Atomically precise Au(n) nanoclusters (n = number of gold atom in cluster) ideally composed of an exact number of gold atoms have unique core-shell structure and non-metallic electronic properties. The extremely small size of Au25 and Au38 nanoclusters induces a large energy gap in their electronic structures, which gives rise to unprecedented catalytic activity in some chemical reactions. Here we report dehydration of phenylboronic acid to boroxine with small Au25 and Au38 nanocluster catalysts, respectively. Especially, Au25 nanocluster is arranged with Au13 icosahedral core capped by twelve gold atoms as an exterior shell. Au38 nanocluster is a face-fused biicosahedral Au23 core encapsulated by a shell comprised of fifteen gold atoms. Au38 nanoclusters exhibit higher activity than Au25 nanoclusters. This study is an attempt to provide a powerful tool for the catalyst design and to gain a further insight into the correlation of structural properties with catalytic properties.