N-Acetimidamide Functionalized 4-Amino-3,5-dinitropyrazole as an Oxygen-Containing Cation for Thermally Stable...

The formation of ionic energetic materials (IEMs) is one of the effective strategies to balance energetic performance and stability in energetic materials. Although IEM formation has been shown to improve stability, issues such as decreased oxygen balance, density, and energetic performance have not been addressed. Oxygen-containing cations can resolve this energy-stability conflict by diminishing the decrease in density and oxygen balance; however, they are comparatively marginalized and less explored, resulting from their complicated synthetic procedures. In this work, a novel oxygen-containing cationic precursor 2 was synthesized by connecting 4-amino-3,5-dinitropyrazole (ADNP) with acetimidamide via the N-functionalization approach. Further, various energetic salts are synthesized by combining this cation with different N, O-rich anions. The synthesized IEMs using ADNP-based oxygen-rich cation showed significant improvement in energetic (like density, OB) and stability (thermal and physical) properties compared to commonly used N-rich cations and corresponding neutral acidic analogues. All of the compounds are thoroughly characterized through NMR, IR, and elemental analysis, whereas compounds 4, 5, 12, and 14 were further confirmed through single-crystal XRD analysis. This work represents an innovative advancement in the ionic energetic materials (IEMs) field and is expected to accelerate further research and development in this challenging area.