A comparative study of the structures, thermal stabilities and energetic performances of two energetic regioisomers: 3(4)-(4-aminofurazan-3-yl)-4(3)-(4-nitrofurazan-3-yl)furoxan

Abstract

Although energetic regioisomers have attracted intensive attention due to their interesting structure–property correlation, their effective synthesis and accurate identification has remained very difficult. In this paper, we synthesized two energetic regioisomers, namely 3-(4-aminofurazan-3-yl)-4-(4-nitrofurazan-3-yl)furoxan (ANFF-34) and 4-(4-aminofurazan-3-yl)-3-(4-nitrofurazan-3-yl)furoxan (ANFF-43), via a controllable strategy with improved yields of 32% and 38%, respectively. The structures of ANFF-34 and ANFF-43 were unambiguously identified using comparative studies of ¹⁵N NMR and single-crystal X-ray diffraction. Moreover, their thermal behaviours, and non-isothermal thermodynamic parameters were systematically investigated. Both ANFF-34 (T_m: 116.2 °C, T_d: 255.4 °C) and ANFF-43 (T_m: 106.2 °C, T_d: 255.6 °C) have similar thermal decomposition processes to that of DNTF. The superior performances of ANFF-34 (ρ: 1.8 g cm⁻³, D: 8214 m s⁻¹, P: 30.5 GPa, IS > 40 J) and ANFF-43 (ρ: 1.7 g cm⁻³, D: 7868 m s⁻¹, P: 27.0 GPa, IS > 40 J) indicate their great potential to be used as melt-cast carrier explosives. This study provides a solid foundation for the design and synthesis of new energetic compounds through isomer effects.