Jin-Ting Wu

A novel cocrystal explosive NTO/TZTN with good comprehensive properties

In order to decrease the acidity of the highly explosive 3-nitro-1,2,4-triazol-5-one (NTO), we cocrystallized NTO with a nitrogen-rich weak base compound 5,6,7,8-tetrahydrotetrazolo[1,5-b] [1,2,4]-triazine (TZTN) in a molar ratio 1 : 1 to form a novel cocrystal explosive. Structure determination showed that the cocrystal is formed by strong intermolecular hydrogen bond interaction. Optical microscopy demonstrated that the crystal morphology of the cocrystal was significantly improved in contrast to the crystal of NTO and TZTN. The differential scanning calorimetry (DSC) showed that the cocrystal exhibited the enhancement of thermal stability and became less sensitive to impact, compared with the TZTN. Moreover, the results suggested that the NTO/TZTN cocrystal not only has unique performance itself, but also effectively alters the properties of NTO and TZTN.

3,4-Diamino-1,2,4-triazole based energetic salts: synthesis, characterization, and energetic properties

The protonation or metathesis synthesis and energetic properties of a new class of energetic materials, energetic salts of 3,4-diamino-triazole (DATr), are described. They were characterized by Fourier transform infrared spectroscopy (FT-IR), elemental analysis (EA), differential scanning calorimetry (DSC), and X-ray single-crystal diffraction. The DSC results showed that these salts had acceptable thermal stabilities; the decomposition temperatures of these salts, except compound 4, were over 200 °C. The density of the series of salts ranged from 1.704 g cm−3 (2 and 6) to 1.82 g cm−3 (7), placing them in a class of relatively dense compounds, and the heats of formation were calculated with the Gaussian 03 suite of programs. All the salts except 5 exhibited promising detonation performances (detonation pressure: 21.5–32.8 GPa, detonation velocity: 7017–8620 m s−1), which were much higher than both those of TNT, and salt 4 was even comparable to RDX. Impact sensitivities were also determined by hammer tests and the results ranged from 8 J (sensitive) to >40 J (insensitive).

Energetic Salts Based on Tetrazole N-Oxide

Energetic materials (explosives, propellants, and pyrotechnics) are used extensively for both civilian and military applications and the development of such materials, particularly in the case of energetic salts, is subject to continuous research efforts all over the world. This Review concerns recent advances in the syntheses, properties, and potential applications of ionic salts based on tetrazole N-oxide. Most of these salts exhibit excellent characteristics and can be classified as a new family of highly energetic materials with increased density and performance, alongside decreased mechanical sensitivity. Additionally, novel tetrazole N-oxide salts are proposed based on a diverse array of functional groups and ions pairs, which may be promising candidates for new energetic materials.

Energetic salts based on 3-hydrazino-4-amino-1,2,4-triazole (HATr): synthesis and properties

Several novel nitrogen-rich salts of 3-hydrazino-4-amino-1,2,4-triazole (HATr) were synthesized by means of metathesis reactions or Bronsted acid–base reactions in this work. These nitrogen-rich salts were fully characterized by means of single-crystal X-ray diffraction, elemental analysis, and infrared. Their structures showed that the extensive hydrogen bonding interactions between the cations and anions formed a complex 3D network, which contributes to the high density of the salts. Some of these salts exhibited reasonable thermal stability (Td = 168–266 °C) and good impact sensitivities (IS = 4–40 J). In addition, the detonation pressures and velocities of the energetic salts were calculated, ranging from 23.1 GPa to 32.3 GPa and 7421 m s−1 to 8455 m s−1, respectively.

Energetic oxygen-containing tetrazole salts based on 3,4-diaminotriazole.

Energetic mono- and dicationic 3,4-diaminotriazolium salts have been prepared by combining stoichiometric amounts (1:1 or 2:1 molar ratio) of 3,4-diaminotriazole with various oxygen-containing tetrazoles, and the structures have been confirmed by single-crystal XRD for the first time. All structures are dominated by a strong hydrogen-bond network owing to both amino groups and oxygen in the molecule. All salts, except 7, exhibit excellent thermal stabilities with decomposition temperatures over 200 °C. Based on experimental densities and theoretical calculations carried out by using the Gaussian 03 suite of programs, all salts have calculated detonation pressures (20.3-33.9 GPa) and velocities (7095-8642 m s(-1)).

Nitrogen-rich salts of 1-aminotetrazol-5-one: oxygen-containing insensitive energetic materials with high thermal stability

1-Aminotetrazol-5-one (ATO) is a new insensitive nitrogen-rich energetic compound with quite attractive detonation properties (D = 8.88 km s−1, P = 35.0 GPa), but its formation always requires harsh conditions to facilitate the process. In this contribution we presented an improved synthesis route of ATO in excellent yields and high purity. A large variety of nitrogen-rich salts of ATO were synthesized by means of Bronsted acid–base or metathesis reactions, and confirmed by single-crystal X-ray diffraction for the first time. These compounds were fully characterized by FT-IR and multinuclear NMR spectroscopy, elemental analysis (EA) and differential scanning calorimetry (DSC). All the salts except 7a decompose at temperatures over 220 °C; in particular, the aminoguanidinium salt and 3,4-diamino-1,2,4-triazolium salt are fairly stable with a decomposition temperature of 259 °C and 261.5 °C, respectively. Based on heats of formation calculated with Gaussian 09 and combined with experimentally determined densities, detonation properties of the energetic salts were obtained. They exhibit good thermal stability, excellent impact sensitivities (>40 J), reasonable detonation pressures (23.6–31.0 GPa) and velocities (7.53–8.72 km s−1) and might be potentially insensitive energetic materials.

Syntheses, crystal structures and thermal analyses of two new ionic complexes based on 3,4-diamino-1,2,4-triazole

Abstract Two new ionic complexes, (DATr)2[Li2(TNR)2·2H2O]·2H2O (1) and (DATr)[Zn(DATr)Cl3] (2), were synthesized by using 3,4-diamino-1,2,4-triazole (DATr) as outer cation. X-ray single-crystal diffraction analysis revealed that the two complexes crystallize in triclinic and orthorhombic crystal systems, respectively. Differential scanning calorimetry was applied to assess the thermal decomposition behavior and kinetic parameters of decomposition were studied by using Kissinger’s and Ozawa–Doyle’s methods. Furthermore, the critical temperature of thermal explosion and parameters of thermodynamics were obtained.