X-Ray crystal structure, and optical and electrochemical properties of the Au15Ag3(SC6H11)(14) nanocluster with a core-shell structure

We report the X-ray crystallographic structure of an 18-metal atom Au-Ag bimetallic nanocluster (NC) formulated as [Au15Ag3(SC15H11)(14)]. This NC consists of a Au6Ag3 bi-octahedral kernel, which is built up by two octahedral Au3Ag3 units through sharing one Ag3 triangular face. The [Au15Ag3(SC6H11)(14) can be viewed as a core shell structure with the doped Ag atoms as the core and Au atoms as the shell. Detailed analyses by UV-vis spectroscopy, X-ray photoelectron spectroscopy (XPS), and electrochemical measurements clearly show distinct differences in the electronic structure between [Au15Ag3(SC6H11)(14) and the homometal [Au-18(SC6H11)(14)] NC. This study contributes to the deep understanding on bimetallic nanoclusters.