Doping effect on a two-electron silver nanocluster

Abstract

This study investigates the effects of metal addition and doping of a 2-electron silver superatom, [Ag₁₀{S₂P(OⁱPr)₂}₈] (Ag₁₀). When Ag⁺ is added to Ag₁₀ in THF solution, [Ag₁₁{S₂P(OⁱPr)₂}₈(OTf)] (Ag₁₁) is rapidly formed almost quantitatively. When the same method is used with Cu⁺, a mixture of alloys, [Cu_xAg_11−x{S₂P(OⁱPr)₂}₈]⁺ (x = 1–3, Cu_xAg_11−x), is obtained. In contrast, introducing Au⁺ to Ag₁₀ leads to decomposition. The structural and compositional analysis of Ag₁₁ was characterized by single-crystal X-ray diffraction (SCXRD), ESI-MS, NMR spectroscopy, and DFT calculations. While no crystal structure was obtained for Cu_xAg_11−x, DFT calculations provide insights into potential sites for copper location. The absorption spectrum exhibits a notable blue shift in the low-energy band after copper doping, contrasting with that of the slight shift observed in 8-electron Cu-doped Ag nanoclusters. Ag₁₁ and Cu_xAg_11−x are strongly emissive at room temperature, and solvatochromism across different organic solvents is highlighted. This study underscores the profound influence of metal addition and doping on the structural and optical properties of silver nanoclusters, providing important contributions to understanding the nanoclusters and their photophysical behaviors.