Distinguishing the Packing Modes of Planar Energetic Molecules with Two “H₂N–C–C–NO₂” Groups Based on π-Holes

Abstract

Energetic materials (EMs) with layered packing structures exhibit good balances between high energy and low sensitivity, while it is a challenge to create them due to unclear correlations between planar molecules and packing modes. In this work, a systematic investigation on 10 geometrically similar planar EMs was performed with the help of computational methods, aiming to dig out the dominant factors responsible for layered and non-layered packing modes. After a comprehensive analysis, including packing structures, Hirshfeld surfaces, energy frameworks, the "Atoms in Molecules" theory, molecular electrostatic potential, and so on, we found that π-holes around C−NO 2 bonds can act as indicators to distinguish layered and non-layered packing modes. The π-holes with a positive electrostatic potential and a large region can form directional interactions with electron-rich nitro groups, resulting in non-layered packing structures. Thus, it is reasonable that no obvious π-holes are observed in the layered energetic crystals. The present contribution is hopefully to accelerate the development of advanced layered EMs.

Synthesis of Heat-Resistant and Low-Sensitivity Energetic Materials Based on Hydrazine Bridge Linkage

“…The insensitive energetic compound TATB has vicinal amino−nitro structural characteristics, while compound 2 and compound 4 have similar structural characteristics. 28 As shown in Table 1, compound 2 and compound 4 both have an FS of >360 N and an IS of >40 J, which are comparable to that of TATB (IS = 50 J and FS = 360 N). Therefore, compound 2 and compound 4 both are insensitive energetic materials.…”

“…Additionally, using the conventional BAM technology, the friction sensitivity (FS) and impact sensitivity (IS) of each energetic compound were assessed in order to assess their safety further. The insensitive energetic compound TATB has vicinal amino–nitro structural characteristics, while compound 2 and compound 4 have similar structural characteristics . As shown in Table , compound 2 and compound 4 both have an FS of >360 N and an IS of >40 J, which are comparable to that of TATB (IS = 50 J and FS = 360 N).…”

Manipulating sensitivities of planar oxadiazole‐based high performing energetic materials

“…Organic and inorganic analogues with planar geometries hold promise of many interesting properties and have attracted extensive attention in many fields of chemistry, physics, and materials (Figure 1A) [6]. In energetic materials, the planar packing of molecules may result in better sensitivity properties because of their ability to transform mechanical energy into relative motion between layers [7][8][9][10]. 1,3,5-Triamino 2,4,6-trinitrobenzene (TATB) is a well-known energetic material with high thermal and shock stability due to its planar structure and strong H-bond interactions (Figure 1B).…”