Design and synthesis of a RAHBs-stabilized N-amino energetic coordination compound for enhanced detonation and laser initiation

The energy release of energetic materials fundamentally originates from the cleavage and reorganization of high-energy chemical bonds within molecules. Constructing longer and more stable nitrogen chains represents a key strategy for enhancing detonation performance. Based on a isomerization design strategy, this study selected 1-amino-1H-pyrazole-5-carbohydrazide (APCA) as the ligand. By introducing an N-amino group adjacent to the carbohydrazide, a resonance-assisted hydrogen bond (RAHB) was successfully constructed, significantly improving the stability of the nitrogen chain. Using this ligand, a new energetic coordination compound, Cu(HAPCA)₂(ClO₄)₄ (ECC-1), was synthesized via a multicomponent self-assembly approach. ECC-1 combines structural features of both ionic salts and coordination compounds, exhibiting high oxygen balance (OB = +6.4 %) and good thermal stability (T_d = 177 °C). The abundance of N-N bonds within its structure significantly contributes to its high heat of formation and superior detonation performance, with a theoretical detonation velocity of 8.1 km s⁻¹ and detonation pressure of 32.3 GPa. Furthermore, laser ignition tests demonstrated that ECC-1 can be rapidly initiated (delay time = 2.6 ms) by low-energy laser stimulation (26 mJ) and successfully detonate RDX charge. Thus, ECC-1 not only achieves a balance between high energy content and stability through regioisomerization and RAHB strategies, also exhibits excellent laser sensitivity, making it a promising candidate material for laser-initiated explosives.