Magic Silica Clusters as Nanoscale Building Units for Super-(Tris)tetrahedral Materials

Abstract

For bridging between the building block and the bulk, we consider the assembly of highly stable (SiO2)8 “magic” clusters into inorganic framework materials. Our cluster building blocks are predicted to be strongly energetically preferred while also having the propensity to form intercluster siloxane (Si−O−Si) bridges. Silicate framework materials are thus proposed with their viability judged via state-of-the-art density functional calculations. All frameworks differ from known synthesized materials with the most stable frameworks lying in a thermodynamically accessible window shared by mesoporous silicas. A few frameworks also correspond to hypothetical frameworks discovered through top-down mathematical approaches providing a link between high-level searches and our bottom-up constructive approach. We predict that the gas-phase deposition of magic clusters will potentially allow the fabrication of new framework materials not readily achievable through traditional hydrothermal syntheses.