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

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 (Tm: 116.2 °C, Td: 255.4 °C) and ANFF-43 (Tm: 106.2 °C, Td: 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.