Structural Evolution and Electronic Properties of VSi ( = 7-14) Clusters: Anion Photoelectron Spectroscopy and Theoretical Calculations.

A systematic study of the structures and electronic properties of V-doped silicon clusters, VSi ( = 7-14), was carried out by anion photoelectron spectroscopic experiments combined with theoretical calculations. According to the experimental spectra of VSi ( = 7-14) clusters, the VSi cluster has the highest vertical detachment energy (VDE) of 3.66 eV, while VSi and VSi clusters have lower VDEs of 2.81 and 2.84 eV, respectively. The most stable structure searches find that two V atoms in the VSi clusters with size = 7 and 8 are located at the surface, while VSi clusters with ≥ 9 prefer cage-like structures. Based on the analysis of the structural evolution of VSi ( = 9-14) clusters, it can be clearly seen how the antihexagonal prism with one V encapsulated in the cage is gradually built from = 9 to 12 and further developed from = 12 to 14 with the extra silicon atoms located at the surface of the Si cage. The molecular orbital and the atoms in molecule analysis of the VSi ( = 7-14) anions demonstrate that the strong V-V bond and the delocalized interaction between the V moiety and the Si ligand play a significant role in stabilizing the cluster structures. A strong linear correlation has been found between the Wiberg bond order of the V-V bond and the electron density at the V-V bond critical points.