The photoelectron spectra of Au2Sin (n = 1–7) clusters were measured, and the structural evolution and bonding properties of Au2Si1–7 anions and their corresponding neutral counterparts were investigated by theoretical calculations. The two Au atoms in Au2Si1–7−/0 prefer to occupy low coordinate sites and form fewer Au–Si bonds. The aurophilic interaction is fairly weak in these clusters. The most stable structures of both Au2Sin anions and Au2Sin neutrals can be described as the two Au atoms interacting with the Sin frameworks. The most stable isomers of Au2Sin anions are in spin doublet states, while those of the neutral clusters are in spin singlet states. The lowest-lying isomers of Au2Si1−/0 have C2v symmetric V-shaped structures. The global minimum of the Au2Si2 anion has a D2h symmetric planar rhombus structure, while that of the Au2Si2 neutral adopts a C2v symmetric dibridged structure. In Au2Si3−/0, the two Au atoms independently interact with the different Si–Si bonds of the Si3 triangular structure. The global minima of Au2Si4–7−/0 primarily adopt prismatic based geometries. Interestingly, Au2Si6−/0 have significant 3D aromaticity and possess σ plus π double bonding characters, which play important roles in their structural stability.

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