Structural Evolution and Bonding Properties of Cr2Sin- (n=1-12) Clusters: Mass-Selected Anion Photoelectron Spectroscopy and Theoretical Calculations

We investigated the structural characteristics and bonding properties of Cr2Sin- (n = 1-12) clusters by using anion photoelectron spectroscopy combined with density functional theory calculations. The experimental and theoretical results reveal that Cr atoms of the most stable structures of Cr2Sin- clusters with n < 8 are located at the surface, while the most stable structures of Cr2Sin- clusters with n >= 8 have one Cr encapsulated in the cage consisting of the other Cr atom and the Si atoms. The Cr-Cr interaction in the most stable structures of Cr2Sin- clusters is strong, except that the Cr-Cr interaction in the lowest lying isomer of the Cr2Si5- cluster is weak. The structure of Cr2Si6- can be viewed as the Cr-2 surrounded by a chair-shaped silicon six-membered ring with the C-2h symmetry. Cr2Si12- has a C-6v symmetric antihexagonal prism structure with two Cr atoms located at the center and the surface of the Si-12 cage, respectively. The magnetic moments of Cr2Sin- are 1 mu B except that the magnetic moment of Cr2Si5- is 9 mu B.

Automated summary

In this study, we investigated the structural characteristics and bonding properties of Cr2Sin- clusters using experimental and theoretical methods. It was found that for n < 8, the most stable structures have surface Cr atoms, while for n >= 8, the most stable structures have one Cr atom encapsulated in a cage formed by other Cr atoms and Si atoms.