Constructing a framework with 1,3,4-oxadiazole and pyrazole for new high energy insensitive salts

A novel neutral tricyclic energetic compound 5,5' -(4-nitro-1H-pyrazole-3,5-diyl) bis (1,3,4-oxadiazol-2-amine) and a series of corresponding energetic ionic salts <bold>7</bold>-<bold>9</bold> were synthesized. Differential scanning calorimetry (DSC), nuclear magnetic resonance (NMR), elemental analysis, and infrared spectroscopy (IR) were used to analyze the newly synthesized compounds. Single-crystal X-ray diffraction was also used to validate the precise structure of ammonium salt <bold>7</bold>. These energetic salts exhibit positive heat of formation (401.17 kJ<middle dot>mol(-1) to 690.66 kJ<middle dot>mol(-1)), moderate detonation performance (8517 m<middle dot>s(-1) to 8803 m<middle dot>s(-1)) and low mechanical sensitivity (IS > 40 J; FS > 360 N). It is worth noting that, in comparison to previously reported energetic salts containing nitramino 1,3,4-oxadiazole with poor thermal stability, the beginning decomposition temperatures of hydroxylamine salt <bold>9</bold> is greater than 180 degrees C. The newly synthesized hydroxylamine salt <bold>9</bold> has promise to be used as new high energy insensitive material based on the aforementioned characteristics.