Revealing Solid Properties of High-energy-density Molecular Cocrystals from the Cooperation of Hydrogen Bonding and...

In the domain of high-energy-density materials, the understanding to physico-chemical properties has long been primarily based on molecular structures whereas the crystal packing effect that significantly affects solid properties has been seldom involved. Herewith we predict the solid properties of six novel energetic cocrystals by taking into account of the crystal packing effect using a quantum chemistry method. We discover that the hydrogen bonding causes an increase in the molecular polarizability and their cooperation significantly changes the solid-state nature of the cocrystals compared to the pristine crystal and the gas counterparts. For example, stabilizing the multi-component molecular association by increasing the binding energy by 19-41% over the pristine crystals, improving the detonation performance by 5-10% and reducing the sensitivity to external stimuli compared to their pure crystal or gas counterparts. Therefore, the solid nature of the cocrystal is not a simple combination of the pure crystalline properties of its components and the heterogeneous molecular coupling effects must be considered to design improved functional cocrystals.