A promising hydrogen peroxide adduct of ammonium cyclopentazolate as a green propellant component

Abstract

A novel H₂O₂ adduct of ammonium cyclopentazolate, NH₄N₅·½H₂O₂, was readily synthesized by a simple and effective method. This adduct, as determined by single-crystal X-ray diffraction, has a cyclo-N₅⁻ anion, an ammonium ion and ½H₂O₂ molecule in the asymmetric unit. In this structure, H₂O₂ molecules are incorporated into the crystal lattices of NH₄N₅, forming an interesting three-dimensional (3D) network structure in which cyclo-N₅⁻ ions are stacked layer by layer and NH₄⁺ ions are intercalated into the layers and connected the layers through hydrogen bonds. This novel solvate, NH₄N₅·½H₂O₂, has a high oxygen balance (−22.86% based on CO₂), high calculated detonation velocity and pressure (8938 m s⁻¹ and 26.37 GPa) and an impressive specific impulse (259.97 s) much higher than that of anhydrous NH₄N₅. Moreover, the combustion products of this solvate mainly include nontoxic N₂, H₂ and H₂O. This simple and effective strategy of combining NH₄N₅ with H₂O₂ is highly desirable for future studies on the development of disruptive energetic materials.