Pressure-induced hydrogen bonds reconstruction of energetic material 3,6-dihydrazino-1,2,4,5-tetrazine: A DFT study

Pressure-induced changes in molecular structure can result in the reconstruction of hydrogen bonds. The structure and vibrational properties of hydrogen-bonded material 3,6-dihydrazino-1,2,4,5-tetrazine were calculated to 50 GPa. When compression, the compressibility displays anisotropy. At 37 GPa, the N-H length increases abruptly to 1.51 Å, suggesting that N-H has broken. The discontinuous changes indicate that 37 GPa is a critical point for structural changes. The hydrogen bond network becomes strengthened, resulting in a decrease in the vibrational activity of NH/NH₂. At 37 GPa, the direction of NH correlated vibration modes change. In Hirshfeld analysis, the strengthening of N…H interactions was confirmed.