Fast Synthesis of Thiolated Au25 Nanoclusters via Protection-Deprotection Method

This letter reports a new synthesis strategy for atomically precise Au nanoclusters (NCs) by using a protection-deprotection method. The key in our synthesis strategy is to introduce a surfactant molecule to protect thiolate-Au(I) complexes during their reduction. The protecting layer provides a good steric hindrance and controls the formation rate of thiolated Au NCs, which leads to the direct formation of atomically precise Au NCs inside the protecting layer. The protecting layer was then removed from the surface of thiolated Au NCs to bring back the original functional groups on the NCs. The protection-deprotection method is simple and facile and can synthesize high-purity thiolated Au25 NCs within 10 min. Our synthesis protocol is fairly generic and can be easily extended to prepare Au25 NCs protected by other thiolate ligands.