Fascinating 3D energetic [Ag2(N5)2(EDA)]n: filling the ethylenediamine molecules into a [Ag(N5)]n framework

Abstract

An interesting 3D energetic motif based on Ag(I) ion, cyclo-pentazolate anion (cyclo-N₅⁻) and ethylenediamine (EDA), namely, [Ag₂(N₅)₂(EDA)]_n, was prepared by embedding the ethylenediamine molecules into the [Ag(N₅)]_n structure. The architecture was determined by single-crystal X-ray diffraction. The onset decomposition temperature of [Ag₂(N₅)₂(EDA)]_n was 6.4 °C higher than that of [Ag(N₅)]_n and 14.6 °C higher than that of [Ag₃(N₅)₄]_n·n[Ag(NH₃)₂]. The detonation performance (D = 6.272 km s⁻¹, P = 23.51 GPa) of [Ag₂(N₅)₂(EDA)]_n was between that of [Ag(N₅)]_n and [Ag₃(N₅)₄]_n·n[Ag(NH₃)₂]. The insertion of EDA molecules resulted in a significant reduction of the mechanical sensitivity compared with extremely sensitive [Ag(N₅)]_n. It is an effective way to improve the stability of pentazolate complexes using amino-containing small molecules with cyclo-N₅⁻ to form bi-ligand energetic metal–inorganic frameworks.