Photoelectron Spectroscopy and Density Functional Calculations of TiGe_n^- (n=7-12) Clusters

The growth pattern and electronic properties of TiGe_n^- (n=7-12) clusters were investigated using anion photoelectron spectroscopy and density functional theory calculations. For both anionic and neutral TiGe_n clusters, a half-encapsulated boat-shaped structure appears at n=8, and the boat-shaped structure is gradually covered by the additional Ge atoms to form Ge_n cage at n=9-11. TiGe₁₂^- cluster has a distorted hexagonal prism cage structure. According to the natural population analysis, the electron transfers from the Ge_n framework to the Ti atom for TiGe_n^-/0 clusters at n=8-12, implying that the electron transfer pattern is related to the structural evolution.