[5,5]‐Fused Heterocycle‐Bridged Bistetrazoles Enable High‐Energy and Insensitive Nitrogen‐Rich Materials

Constructing bridged bistetrazole frameworks is an established strategy for tuning the performance and safety of nitrogen‐rich energetic materials. Here, we introduce a rigid [5,5]‐fused heterocycle as a structural bridge to access a family of bistetrazole‐based energetic compounds ( 2 , 5 , 6 , and 2a–2d ) through a concise and efficient synthetic route. These compounds exhibit high density ( ρ = 1.79–1.90 g cm −3 ), excellent thermal stability ( T d = 181–354°C), and favorable mechanical insensitivity ( IS = 16–30 J; FS = 240–360 N). Notably, the energetic salts 2c ( D v = 9285 m s −1 ) and 2d ( D v = 9551 m s −1 ) outperform the benchmark explosive RDX ( D v = 8814 m s −1 ). These results demonstrate that [5,5]‐fused‐ring bridging provides an effective design principle for achieving synergistic enhancement of energy density and safety, offering a powerful platform for the development of next‐generation energetic materials.