Zero-oxygen balanced fused 1,2,3,4-tetrazine (TNF) as a high-performance energetic material

Abstract

Oxygen balance is a crucial index of energetic materials that indicates the efficiency of the redox process during energy release. In this work, a straightforward synthesis, including N-amination and azo-coupling oxidative cyclization, gave rise to 2,9-bis(trinitromethyl)bis([1,2,4]triazolo)[1,5-d:5′,1′-f][1,2,3,4]tetrazine (TNF), achieving an ideal zero oxygen balance in the tetrazine–triazole framework. With a high crystal density of 1.94 g cm⁻³ at 296 K (1.995 g cm⁻³ at 150 K), TNF features an excellent detonation performance (P = 39.7 GPa, V_D = 9470 m s⁻¹), which remarkably surpasses those of RDX (P = 34.9 GPa; V_D = 8795 m s⁻¹) and HMX (P = 39.2 GPa; V_D = 9144 m s⁻¹). Furthermore, the excellent heat of detonation (Q = 7154 kJ kg⁻¹) of TNF significantly exceeds the state-of-the-art explosive CL-20 (Q = 6534 kJ kg⁻¹). Additionally, the evaluation of specific impulse values of two new compounds, TBTD and TNF, reveals notably high values of 272 s and 269 s, respectively. It possesses the application potential as a high-energy oxidizer, especially in the formulation of solid rocket propellants.