The pentazolate anion, as a polynitrogen species, holds great promise as a high-energy density material for explosive or propulsion applications. Designing pentazole complexes that contain minimal non-energetic components is desirable in order to increase the material’s energy density. Here, we report a solvent-free pentazolate complex, AgN₅, and a 3D energetic-framework, [Ag(NH₃)₂]⁺[Ag₃(N₅)₄]ˉ, constructed from silver and cyclo-N₅ˉ. The complexes are stable up to 90 °C and only Ag and N₂ are observed as the final decomposition products. Efforts to isolate pure AgN₅ were unsuccessful due to partial photolytical and/or thermal-decomposition to AgN₃. Convincing evidence for the formation of AgN₅ as the original reaction product is presented. The isolation of a cyclo-N₅ˉ complex, devoid of stabilizing molecules and ions, such as H₂O, H₃O⁺, and NH₄⁺, constitutes a major advance in pentazole chemistry.

23 nitrogens and only one phosphorus: The N₅⁺ ion is combined with energetic anions in the form of N₅⁺ [P(N₃)₆]⁻ and N₅⁺ [B(N₃)₄]⁻ (see scheme), containing 91 and 96 wt %, respectively, of nitrogen. Also, the thermally unstable compound N₅HF₂⋅n HF is prepared by metathesis from N₅SbF₆ and CsHF₂. Its usefulness as a reagent for the synthesis of new N₅⁺ salts is demonstrated with the preparation of N₅PF₆, N₅BF₄, and N₅SO₃F.

A cyclo -N ₅ ⁻ anion has been synthesized as a stable salt and characterized

Bang on target: The highly explosive Group 6 azides Mo(N₃)₆ and W(N₃)₆ are prepared by the reaction of Me₃SiN₃ with MoF₆ and WF₆, respectively. The structure of W(N₃)₆ has perfect rhombohedral C₃ symmetry (see picture). The reaction of Mo(N₃)₆ and W(N₃)₆ with ionic azides leads to the formation of [Mo(N₃)₇]⁻ and [W(N₃)₇]⁻, respectively, the first binary heptaazides. Controlled decomposition of these anions produces [NMo(N₃)₄]⁻ and [NW(N₃)₄]⁻. <!--EMPTY SOURCE-->

Highly explosive Te(N₃)₄ was prepared by the fluoride-ion-catalyzed reaction of TeF₆ and Me₃SiN₃, and converted to the more stable [P(C₆H₅)₄]₂[Te(N₃)₆] salt by reaction with [P(C₆H₅)₄]N₃. The sterically active free valence-electron pair at the Te center strongly distorts the structure of the [Te(N₃)₆]²⁻ ion from the predicted ideal S₆ symmetry (see picture). Evidence for the formation of the [Te(N₃)₅]⁻ ion is also presented. <!--EMPTY SOURCE-->