Imino-bridged N-rich energetic materials: C4H3N17 and their derivatives assembled from the powerful combination of four tetrazoles

Abstract

This study reports the synthesis of a series of novel imino-bridged N-rich energetic compounds, namely C₄H₃N₁₇ (N%: 82.4) and their derivatives, which were formed by four tetrazole (CN4) moieties. C₄N₁₇³⁻ could be acidified by different concentrations of HCl and N-rich anions such as C₄H₂N₁₇⁻ and the neutral compound 3 (C₄H₃N₁₇) could be obtained. The new compounds all exhibit good energetic performance (D: 8023–9668 m s⁻¹; Td: 169–277 °C; IS > 25 J; FS > 252 N). Remarkably, the ammonia oxide adduct compound 8 (C₄H₁₅N₂₁O₄) was exceedingly powerful (D: 9668 m s⁻¹) similar to CL-20 (9706 m s⁻¹) and showed good stability (Td: 168 °C; IS > 40 J; FS > 360 N). Moreover, compound 11 (C₄H₈NaN₁₉) exhibits not only the thermal stability and high density of metallic salts but also the mechanical stability of nonmetallic salts, which provides an important strategy for the design and synthesis of energetic materials. Among them, compounds 3, 4, and 6–11 were characterized via single-crystal diffraction to further confirm their exact molecular structure and arrangement.