Symmetry, Conjugated System, and N-oxides in 2,4,6-Trinitro-1,3,5-triazine-1,3,5-trioxides: A New Design Concept for Energetic Oxidizers

Abstract

ABSTRACTA new strategy for an energetic oxidizer, 2,4,6-trinitro-1,3,5-triazine-1,3,5-trioxides (TNTATO), was designed by keeping symmetry and conjugation and introducing N-oxides into 1,3,5-triazine. Molecular mechanics (MM) and density functional theory (DFT) were employed to study the crystal structure, infrared (IR) spectrum, electronic structure, thermodynamic properties, gas-phase and condensed-phase heats of formation, detonation performance, and burning rate of TNTATO. The pyrolysis mechanism and thermal stability were predicted by evaluating the bond dissociation energy (BDE) and activation energy. The calculated results indicate that TNTATO has a symmetric hyperconjugation structure, which contributes to its stability. The BDE (210.64 kJ/mol−1) and activation energy (27.74 kJ/mol−1) of the weakest bond C3–N8 show that the C–NO2 bond is the trigger bond during thermolysis. The detonation velocity (8.51 km/s−1) and detonation pressure (32.69 GPa) are larger than those of 2,4,6-trinitro-1,3,5-triazine (TNTA). TNTATO exhibits better burning properties than ammonium dinitramide (ADN), indicating that TNTATO may be a potential candidate for a highly energetic oxidizer.