One-step amino-to-nitro transformation of carbonyl-containing fused-ring energetic compounds in nitric acid

Backbone construction and ionic modulation are effective strategies for improving energetic material performance. In this work, we report the successful synthesis and detailed characterization of a carbonyl-containing fused triazolotriazine compound (3). Its perchlorate salt (4) features a dense crystal lattice and exhibits a high density (1.90 g cm⁻³) with good detonation performance (D = 8382 m s⁻¹; P = 30.74 GPa) and low mechanical sensitivities [impact sensitivity (IS) > 40 J; friction sensitivity (FS) > 360 N], surpassing those of TNT. Direct oxidation of the amino group in 3 using fuming HNO₃ yields the nitro compound 5, with HNO₃ as the sole oxidant. Among 4, 5, and its ammonium salt 6, the perchlorate salt 4 achieves the most favorable balance between energetic output and structural stability. This work highlights the synthesis and systematic characterization of these novel fused-triazolotriazine derivatives, offering a practical route toward high-energy, low mechanical sensitivity energetic materials.