Customization of the molecular structure to modulate the crystal packing style of energetic materials†
The crystal packing style of energetic compounds has a significant impact on their safety. Herein, using Multiwfn, the interactions of ANPZ (2,6-diamino-3,5-dinitropyrazine) and DMDNP (2,6-dimethoxyl-3,5-dinitropyrazine), having the same dinitro-pyrazine ring with different crystal packing styles, were visualized to investigate the assembly of the corresponding crystal packing styles. Via the customization of the molecular structure, A1 and A2 compounds were synthesized to regulate the interactions to achieve the other two crystal packing styles. To further utilize this strategy and balance the contradiction between the energy content and safety of the energetic materials, the compound A3 was customized by the addition of an N–O group into the structure of A1. The crystal was modulated into a more impact-insensitive packing style while maintaining similar energy content as that in A1. All these results confirm that this strategy can be utilized to design and synthesize novel insensitive energetic materials.