Cocrystal of Configurational/Conformational Isomers in Energetic Materials: Binitroaminofurazan with a 1,2,4,5-Tetrazine Bridge

The design, synthesis, calculated performances, and physical properties of two <i>cis</i>/<i>trans</i> isomers of binitroaminofurazan linked by a 1,2,4,5-tetrazine moiety are described. By modifying the conditions, crystal of <i>trans</i>-<b>5</b> and cocrystal of <i>cis</i>/<i>trans</i>-<b>5</b> were successfully obtained. Both configurations of compound <b>5</b> are stabilized by two hydrogen bonds, which enhances their thermal stability. The cocrystal of <i>cis</i>/<i>trans</i>-<b>5</b> represents the first instance of configurational/conformational isomers in cocrystals within the field of energetic materials. It exhibits superior physical properties, including thermal decomposition temperature, density, impact sensitivity, and friction sensitivity, compared to those of <i>trans</i>-<b>5</b>, and demonstrates certain physical properties, which exceed those of RDX and HMX. This finding underscores the importance of considering configuration, conformation, and cocrystal formation when designing compounds as potential energetic materials.