Synthesis, thermal behaviors, and energetic properties of asymmetrically substituted tetrazine-based energetic materials

Abstract

1,2,4,5-tetrazine ring is a common structure for the construction of energy-containing compounds, and its high nitrogen content and large conjugation effect give it the advantage of a good balance between energy and mechanical stability as a high-nitrogen energy-containing material. However, most of the reported works about tetrazine energetic materials (EMs) are symmetrically substituted tetrazines due to their easy accessibility. A small number of reports show that asymmetrically substituted tetrazines also have good properties, such as high density and generation of enthalpy and energy. Herein, two asymmetrically substituted tetrazines and their five energetic salts were prepared and fully characterized by IR spectroscopy, NMR spectra, elemental analysis, and differential scanning calorimetry (DSC). The structure of the two compounds was further confirmed by single-crystal X-ray diffraction studies. The thermal behaviors and thermodynamic parameters were determined and calculated. In addition, the energetic properties and impact sensitivities of all the compounds were obtained to assess their application potential. The results show that compounds 2–4 and 7–9 show higher detonation velocities than TNT, and the hydrazinium salt 9 possesses the best detonation properties (D = 8,232 m s−1 and p = 23.6 GPa). Except for 4 and 3, all the other compounds are insensitive, which may be applied as insensitive explosives. Noncovalent interaction analysis was further carried out, and the result shows that the strong and high proportion of hydrogen bonds may contribute to the low-impact sensitivity.

A new class of unique quinoidal-like imidazoliumyl tetrazinides: synthesis, structure, and mechanism

“…Tetrazinone has gained increasing attention in recent years, mostly owing to its application in organic synthesis, [1][2][3][4][5][6] energetic materials, [7][8][9] magnetic materials, 10,11 organic electronics, 12 and pharmaceutical chemistry. 13,14 Tetrazinone with a carbonyl group and four nitrogen atoms in the same six-membered ring is classified as 1,2,3,4-tetrazinone, 1,2,3,5-tetrazinone, and 1,2,4, 5-tetrazinone based on the position of nitrogen atoms in the tetrazine ring (Fig.…”

Polyvalent Ionic Energetic Salts Based on 4-Amino-3-hydrazino-5-methyl-1,2,4-triazole

“…Triazole is the representative of high nitrogen-containing compounds and increasingly attracts considerable interest. In energetic skeletons such as those of imidazole [6], triazole [7], tetrazole [8], triazine [9], and tetrazine [10], 1,2,4-triazole shows unique advantages.…”