Photochemical Synthesis of Atomically Precise Ag Nanoclusters

Photochemical methods are effective for controllablesynthesisof silver nanoparticles with specific sizes and shapes. Whether theyare capable of fabricating Ag nanoclusters (NCs) with atomic precisionis yet to be proved. In this work, we synthesize an atomically precise Ag NC, [Ag-25(4-MePhC C)(20)(Dpppe)(3)](SbF6)(3) (Ag-25), via a process mediated by visiblelight. Its total structure is determined by X-ray crystallography.The investigation of the mechanism reveals that the formation of Ag-25 is triggered by a photoinduced electron-transfer (PET) process. An electron of certain amines isexcited by light with wavelength shorter than 455 nm and transferred to Ag+. The amine is oxidized to the corresponding amine N-oxide. Such a PET process is supported by experimental and density functional theory studies. To expand the application scope of the photochemical method, another three NCs, [Ag-19(4-(BuPhC)-Bu-t C)(14)-(Dpppe)(3)](SbF6)(3) (Ag-19), [Ag-32(4-(BuPhC)-Bu-t C)(22)-(Dppp)(4)](SbF6)(3) (Ag-32), and bimetallic [Ag22Au3(4-(BuPhC)-Bu-t C)(20)-(Dpppe)(3)](SbF6)(3) (Ag-22 Au-3), are produced by replacing certain ingredients. Furthermore,since the formation of Ag-19 can be regarded as a photochromatic process, a facile amine visual detection method is also presented based on this mechanism.

Automated summary

Photochemical methods are used for controllable synthesis of silver nanoparticles with specific sizes and shapes. This work presents the synthesis of an atomically precise Ag nanocluster (NC), [Ag-25(4-MePhC C)(20)(Dpppe)(3)](SbF6)(3) (Ag-25), through a process mediated by visible light. The total structure of Ag-25 is determined by X-ray crystallography. The formation of Ag-25 is triggered by a photoinduced electron-transfer (PET) process. The study also introduces a facile amine visual detection method based on the photochromatic process of Ag-19. Rating: 9/10.