Embellishing bis-1,2,4-triazole with four nitroamino groups: Advanced high-energy-density materials with remarkable performance and good stability

Preparing high-energy-density materials (HEDMs) with performance comparable or superior to CL-20 has been at the forefront of energetic material research. In response to this challenge, four nitroamino groups were successfully introduced into a bis-1,2,4-triazole backbone to pursue the higher energetic performance. The neutral compound (NT-00) and high-energy salts, including the divalent (D1-D5) and tetravalent (T1-T5) salts were structurally confirmed by single crystal X-ray diffractions. The structural variances among the parent molecule, divalent anion and tetravalent anion were carefully studied to investigate the potential structure-performance relationship. According to experimental and theoretical evaluations, all the prepared materials exhibit excellent physicochemical properties. In particular, NT-00 exhibits the highest density (1.91 g cm-3) and prominent detonation performance (D: 9421 m s-1; P: 40.34 GPa), and two divalent salts D2, D3 feature comparable performance with CL-20 (D: 9597 and 9609 m s-1; P: 40.35 and 42.42 GPa). Moreover, salt formation greatly improves the thermal and mechanical stability of these high-performance salts (Td: 164-248 °C; IS: 9-15 J; FS: 80-180 N), owing to the extensive hydrogen-bonding interactions between cations and anions. As a result, the tetranitroamino materials reported in this work can be promising candidates for advanced HEDMs.