Heat‐Resistant Energetic Materials Deriving from Benzopyridotetraazapentalene: Halogen Bonding Effects on the Outcome of Crystal Structure, Thermal Stability and Sensitivity

Abstract

AbstractHeat‐resistant energetic material (HREM) has shown its broad applications in petroleum and natural gas exploration, aerospace vehicle as well as solid rocket formulations. Benzopyridotetraazapentalene (BPTAP) (d: 1.84 g cm−3, D: 7670 m s−1, IS: 9 J, Td: 366 °C) is a heat‐resistant energetic material, which is more dense and energetic than those of commercial HREM hexanitrosilbene (HNS) (d: 1.74 g cm−3, D: 7612 m s−1, IS: 5 J, Td: 318 °C). However, low solubility in most of commonly‐used solvents has restricted its applications in detonators as nano‐energetic materials. Meanwhile, recognition on this fused organic backbone is still limited. Herein, we report a chlorine‐inclusion strategy and facile approaches to yield three new derivatives of BPTAP. It is notable that compound 6‐a exhibits its high density (1.92 g cm−3), superior thermal stability (Td: 334 °C), high detonation performance (D: 8084 m s−1), comparable sensitivity (IS: 3 J) to that of HNS, surpassing those of commercially‐used highly‐sensitive primary energetic material lead azide (LA). It is interesting that the chlorine‐inclusion in different position of fused benzopyridotetraazapentalene framework has greatly affected their physical properties such as crystal structure, thermal stability and sensitivity. This investigation offers a unique perspective for deeply exploring the relationship between structure and performance of energetic materials.