Detonation performance enhancement through a positional isomerism modification strategy

Abstract

The design, synthesis, physical properties, and calculated detonation performances of two skeleton isomeric energetic compounds containing tetrazole were introduced. By changing the chemical modification sites of the original fused-pyrimidine skeleton,...

Regulating the Thermal Stability and Energy of Fused-Ring Energetic Materials by Hydrazo Bridging and Hydrogen-Bonding Networks

“…In order to better understand the property difference of compounds 1 , 2 , and III , their electrostatic potentials (ESPs) were calculated and analyzed by using Multiwfn v3.5 software . The electrostatic potentials (ESPs) of III , 1 , and 2 were calculated to understand their intermolecular interactions, which closely affect the densities and impact sensitivities. ,, A larger electrostatic potential difference is more beneficial to form strong intermolecular hydrogen bonds as the driving force of hydrogen bonds is electrostatic attraction. , The electrostatic potential (ESP) surfaces of compounds III , 1 , and 2 are shown in Figure d–f. The electrostatic potential difference of 2 (87.57 kcal·mol –1 ) is smaller than those of 1 (90.01 kcal·mol –1 ) and III (91.15 kcal·mol –1 ), which means that 2 has weaker intermolecular hydrogen bonds than 1 and III .…”

“…54 The electrostatic potentials (ESPs) of III, 1, and 2 were calculated to understand their intermolecular interactions, which closely affect the densities and impact sensitivities. 22,59,60 A larger electrostatic potential difference is more beneficial to form strong intermolecular hydrogen bonds as the driving force of hydrogen bonds is electrostatic attraction. 60,61 The electrostatic potential (ESP) surfaces of compounds III, 1, and 2 are shown in Figure 5d−f.…”

“…The discovery of new energetic materials (EMs) is one of the growing topics in the field of materials science. − One of the long-term objectives in this field is how to design and synthesize new energetic compounds with high energy, good safety, and high thermal stability. − Recent advances have shown that conjugated skeletons, strong intramolecular hydrogen bonds, and π–π interactions, which are structural features of traditional heat-resistant and insensitive EMs such as 1,3,5-triamino-2,4,6-trinitro-benzene (TATB) and 2,6-diamino-3,5-dinitro-pyrazine-1-oxide (LLM-105), contribute to the low sensitivity and high thermal stability of EMs. − Besides, NN/N–N bonds and nitro groups can increase the density and positive heat of formation (Δ H f ) and lead to the high energy density of EMs such as 1,3,5-trinitro-2,4,6-trinitroaminobenzene (TNTNB), 1,5-diaminotetrazole-4N-oxide (SYX-9), and 2,2′-azo-bis­(5-azidotetrazole) . The group of Prof. Ganapathy Vaitheeswaran made some constructive investigations by using calculation methods based on well-known EMs such as ammonium dinitramide (ADN), potassium dinitramide (KDN), 5-aminotetrazole (5-AT), 3,3′-dinitro-5,5′-bis-1,2,4-triazole-1,1′-diolate (DNBTO), 4,4′-bis­(nitramino)­azofurazan (DNAF), and octanitrocubane (ONC), which also support the above rules. − Bicyclic azolo azines constitute a family of nitrogen-rich conjugated 5/6-fused rings that allow all of the above structural features in one molecule, making them popular building blocks to construct new low-sensitivity and high-energy materials.…”