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

Abstract

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 (T_d: 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.