Regulating the Coordination Environment by Using Isomeric Ligands: Enhancing the Energy and Sensitivity of Energetic Coordination Compounds

Transforming the energy storage structure is an effective approach to achieve a balance between the detonation performance and the sensitivity of energetic compounds, with a goal of high energy and low sensitivity. Building upon previous work, this study employed an isomeric compound 1H-pyrazole-3-carbohydrazide (3-PZCA) as a ligand and creatively designed the energetic coordination compound (ECC) Ag(3-HPZCA)2(ClO4)3 (ECC-1). It is a novel material with a dual structure of ionic salts and coordination compounds, which represents the first report of such a structure in Ag(I)-based ECCs. With its unique structures, ECC-1 exhibits a larger [ClO4-] content, a higher oxygen balance constant (OB = 0%), and superior mechanical sensitivity (IS = 13 J and FS = 40 N). Theoretical calculations indicate that ECC-1 has a higher detonation performance compared to previous work. Furthermore, the explosive experiment testing results demonstrate that it can be ignited by lower-threshold lasers and possesses excellent initiation capability and explosive power, making it suitable not only as a primary explosive but also as a secondary explosive.

Bisnitramide-Bridged N-Substituted Tetrazoles with Balanced Sensitivity and High Performance

In this study, a simple synthetic strategy for bridged bis(nitramide)-based N-substituted tetrazoles is described. All new compounds were isolated and fully characterized by sophisticated analytical techniques. The structures of the intermediate derivative and two final compounds were determined by single-crystal X-ray data. The structures of the intermediate derivative and two final compounds were determined by single crystal X-ray data. Thermostabilities and energetic properties of new bridged bisnitramide-based N-substituted tetrazoles were discussed and compared with known materials.

Alkaline metal and alkaline earth metal salts of di(1H-tetrazol-5-yl)methanone (DTO): energetic catalysts for ammonium perchlorate decomposition

Six new coordination complexes were obtained and fully characterized; complexes 4 and 5 exhibit good catalytic performances on AP.

Nitratoethyl-5H-tetrazoles: improving the oxygen balance through application of organic nitrates in energetic coordination compounds

1- and 2-Nitratoethyl-5H-tetrazole (1-NET and 2-NET) were prepared through nitration of the respective alkyl alcohol using 100% nitric acid. A mixture of 1- and 2-hydroxyethyl-5H-tetrazole was obtained after alkylation of 1,5H-tetrazole. Also, a one-pot synthesis of 1-hydroxyethyl-5H-tetrazole was developed enabling the selective preparation of 1-NET. Both organic nitrates were characterized by ¹H, ¹³C, and ¹H-¹⁵N HMBC NMR spectroscopy. In addition, calculations using the Hirshfeld method and the EXPLO5 code were performed. Principally, 20 energetic coordination compounds involving the d-metals Mn, Cu, Zn, and Ag, each structurally characterized by low temperature single crystal X-ray diffraction, were prepared based on 1-NET and 2-NET. Of these complexes, 18 were obtained as pure bulk materials, and therefore, characterized for impact, friction, and ball drop impact sensitivity, as well as electrostatic discharge and thermal stability using differential thermal analysis. Hot plate and hot needle tests were performed mostly showing strong deflagrations making the complexes candidates for green combustion catalysts. Furthermore, successful PETN initiation experiments were carried out for several complexes and all ECCs were investigated by laser ignition experiments.

A Smart Access to the Dinitramide Anion - The Use of Dinitraminic Acid for the Preparation of Nitrogen-Rich Energetic Copper(II) Complexes

Dinitraminic acid (HN(NO₂)₂, HDN) was prepared by ion exchange chromatography and acid‐base reaction with basic copper(II) carbonate allowed the in  situ preparation of copper(II) dinitramide, which was reacted with twelve nitrogen‐rich ligands, for example, 4‐amino‐1,2,4‐triazole, 1‐methyl‐5H‐tetrazole, di(5H‐tetrazolyl)‐methane/‐ethane/‐propane/‐butane. Nine of the complexes were investigated by low‐temperature X‐ray diffraction. In addition, all compounds were investigated by infrared spectroscopy (IR), differential thermal analysis (DTA), elemental analysis (EA) and thermogravimetric analysis (TGA) for selected compounds. Furthermore, investigations of the materials were carried out regarding their sensitivity toward impact (IS), friction (FS), ball drop impact (BDIS) and electrostatic discharge (ESD). In addition, hot plate and hot needle tests were performed. Complex [Cu(AMT)₄(H₂O)](DN)₂, based on 1‐amino‐5‐methyltetrazole (AMT), is most outstanding for its detonative behavior and thus also capable of initiating PETN in classical initiation experiments. Laser ignition experiments at a wavelength of 915 nm were performed for all substances and solid‐state UV‐Vis spectra were recorded to apprehend the ignition mechanism.

Insensitive energetic compounds: alkaline earth metal salts of 5,5′-dinitramino-3,3′-methylene-1H-1,2,4-bistriazolate

Three insensitive energetic alkaline earth metal salts based on 5,5′-dinitramino-3,3′-methylene-1H-1,2,4-bistriazolate were synthesized. All the salts exhibit explosive properties comparable to TNT, and are suggested as potential energetic materials.