Noncovalent modification induced 2D planar stacking: A promising strategy for high-energy insensitive materials

Abstract

Exploring new energetic materials with high energy and high stability is a long-term goal in the field of energetic materials. Crystal engineering is recognized to be a promising strategy for balancing energy capability and safety. In this study, newly designed 1:1 energetic salt (compound 2) constructed by pairing 3-amino-4-(4,5-diamino-1,2,4-triazole-3-yl)-furazan with 4-amino-1,2,5-oxadiazole-3-carboxylic acid was achieved by the simple acid−base reaction method. The structure of target compound was determined and characterized by nuclear magnetic resonance (NMR) spectrometers, Infrared (IR) spectroscopy, differential scanning calorimetry (DSC), simultaneous thermal analyzer (TGA-DSC) and single-crystal X-ray diffraction. It was found that compound 2 possesses desirable face-to-face π-stacking, which promote molecular stability. The structure-property relationship was investigated from experimental results and quantum chemical calculations. The ideal structure gives rise to high energetic performances (D = 8545 m s−1; P = 30.4 GPa), good thermal stability (Td = 236.6 ℃) and low sensitivity (IS = 34 J, FS = 350 N). These fascinating results suggesting that two dimension (2D) planar stacking could effectively modulate energy and safety.