Nitrogen-Rich 5,5′-Bistetrazolates and their Potential Use in Propellant Systems: A Comprehensive Study

A large variety of twice‐deprotonated nitrogen‐rich 5,5′‐bistetrazolates, that is, the ammonium (1), hydrazinium (2), hydroxylammonium (3), guanidinium (4), aminoguanidinium (5), diaminoguanidinium (6), triaminoguanidinium (7), and diaminouronium (8) salts, have been synthesized. Energetic compounds 1–8 were fully characterized by single‐crystal X‐ray diffraction (except 8), NMR spectroscopy, IR and Raman spectroscopy, and differential scanning calorimetry (DSC) measurements. With respect to their potential use in propellant applications, the sensitivity towards impact, friction, and electrical discharge were determined. Several propulsion and detonation parameters (e.g., heat of explosion, detonation velocity) were computed by using the EXPLO5 computer code based on calculated (CBS‐4M) heats of formation and X‐ray densities. Additionally, the performance of 1–8 in various formulations was investigated by calculating the specific energy and specific impulse of the compounds under isochoric conditions. The thrust generation: The synthesis and complete characterization of a series of nitrogen‐rich salts of 5,5′‐bistetrazole gave promising materials with potential applications in novel propellant systems (see figure). In addition to their good thermal and chemical stability, the high nitrogen content leads to good N2/CO ratios when combusted, which is desirable to avoid environmental and corrosion problems.