Synthesis and Structure–Property Relationships of 5/8/5 Fused Tricyclic Energetic Materials Via Triazinane-to-Tetrazocane Skeleton Transformation

A 5/8/5 fused tricyclic energetic skeleton was constructed via triazinane-to-tetrazocane transformation under a rigidity-flexibility design strategy. Compound 4 shows balanced energetic behaviors, while nitramine-functionalized compound 5 achieves superior detonation velocity beyond 1,3,5-trinitro-1,3,5-triazinane with increased sensitivity. Crystal analysis reveals conformational conversion and packing regulation. Hirshfeld surface analysis clarifies intermolecular interactions related to mechanical sensitivity. This work provides a route for fused polycyclic skeletons and guides functional modification of energetic materials.