Cocrystal Engineering of a Prototype Energetic Material: Supramolecular Chemistry of 2,4,6-Trinitrotoluene

A unique approach to alter the properties of existing energetic materials through cocrystallization is presented. The structure and properties of 17 new cocrystals of the benchmark energetic material 2,4,6-trinitrotoluene (TNT) are elucidated. The donor−acceptor π−π interaction represents a reliable supramolecular synthon for the formation of cocrystals with this aromatic energetic material. When present, amine−nitro interactions direct secondary packing in these crystals. A detailed study of the cocrystals formed reveals an alteration of key properties including density, packing coefficient, melting point, and decomposition temperature. Cocrystallization provides the opportunity to tune properties of existing energetics to create superior materials and provides a complementary alternative to traditional methods that focus primarily on the synthesis of new compounds and/or the discovery of polymorphs with the most attractive properties.