Molecular Design of Amorphous Porous Organic Cages for Enhanced Gas Storage

Porous molecular solids are garnering increasing attention with examples of high surface areas and applications in molecular separations. Recently, amorphous networks of molecular cages have shown increased porosity with respect to their crystalline counterparts. However, the structures of amorphous materials cannot be precisely elucidated by X-ray diffraction techniques, thus molecular simulations are vital to understanding their pore structures and the origin of porosity. Here, we use GPU-accelerated molecular dynamics simulations as an efficient methodology to construct representative amorphous network structures. We employ Voronoi network analysis of amorphous networks of seven previously reported cage molecules to provide insight into structure-property relationships. Accordingly, we apply this understanding to delineate synthetic design features that give rise to highly porous analogues of chemically robust cages constructed from carbon-carbon bonds.