Stabilizing Role of Halide Ions in Endohedral [20]Silafulleranes: Insights from DFT Calculations toward Silicon Nanocages

Abstract

As miniaturization of electronic devices is rapidly approaching the nanoscale, a deeper understanding of the electronic and structural properties of silicon nanoclusters, called to be the next-generation materials for circuit design, becomes of paramount importance. Herein, a detailed density functional theory study of the binding forces between [20]silafullerenes frameworks and their central halide ions is conducted, prompted by the recent synthesis of the first discrete Si20 dodecahedra stabilized by an endohedral chloride and valence saturation, [Cl@Si32Cl44]−, as well as the fabrication of the first electron transistor device based on a single silicon cluster. Although more intense stabilizing forces are obtained in the chloride-containing system, a small energetic difference with respect to bromide-centered one is found (4.76 kcal mol–1) suggesting the synthetic accessibility of the latter. An energy decomposition analysis is conducted revealing that in all cases (representing about 71%) the electros...