The new role of 1,1-diamino-2,2-dinitroethylene (FOX-7): two unexpected reactions

Abstract

Two novel derivatives of FOX-7, 2-methyl-5-nitro-1,2,3-triazole-4-amine (MNTzA) and 1,5-bis(1-amino-2,2-dinitrovinyl)carbonohydrazide (BADCh), were synthesized by two unexpected reactions of FOX-7 and hydrazino compounds, and the two reaction processes were analyzed. The reaction to form MNTzA is unusual among the syntheses of 2,4,5-trisubstituted 1,2,3-triazole compounds. The structures of the two compounds were studied by NMR, single crystal X-ray crystallography and theoretical calculations. MNTzA crystallizes in the monoclinic P2(1)/n space group with four molecules per unit cell, and each molecule exhibits good coplanarity. However BADCh shows serious structural distortion giving it a ‘W’ shape and possesses two highly polarized C–C double bonds. The DSC analyses and detonation properties of the two compounds were compared with those of FOX-7 and RDX, and the results indicate that MNTzA is an available intermediate for the synthesis of other complicated 2,4,5-trisubstituted 1,2,3-triazole compounds, and BADCh is an excellent energetic material and exhibits good thermal stability (thermal decomposition peak temperature >250 °C), with lower sensitivity (impact sensitivity >19.6 J and friction sensitivity 16%) and similar detonation properties (detonation pressure 32.1 GPa and detonation velocity 8.6 km s⁻¹) when compared to FOX-7 and RDX.