Synthesis of a bi-heterocyclic skeleton with high HOF and corresponding energetic salts with high heat of detonation

Abstract

Abstract In this work, we successfully synthesized 3-(5-amino-1H-1,2,3-triazol-4-yl)-1,2,4-oxadiazol-5-amine (4) through four steps from 5-amino-1H-1,2,3-triazole-4-carbonitrile, and then applied different nitrification approaches to achieve its single-nitrated and full-nitrated products, namely N-(4-(5-amino-1,2,4-oxadiazol-3-yl)-1H-1,2,3-triazol-5-yl)nitramid (13) and N-(3-(5-(nitroamino)-1H-1,2,3-triazol-4-yl)-1,2,4-oxadiazol-5-yl) nitramide (14). By treating intermediates 13 and 14 with excess free bases, a serial of energetic salts 5–7 and 9–12 were readily obtained. Among these salts, the hydrazinium salt 9 and hydroxylammonium salt 11 possess the best detonation performances (9: P = 30.5 GPa; vD = 8493 m s−1 and 11: P = 33.6 GPa; vD = 8682 m s−1), which are comparable with RDX. The heat of detonation data (Q) of these salts are distributed from 3077 (6) and 5787 J g−1 (11). Among them, dihydroxylammonium salt (11) has the most outstanding heat of detonation data reaching 5787 J g−1.