Re-engineering of the FOX-7 structure: computational assessment of structural modifications on explosive performance and safety

Abstract

The demand for energetic materials with high-performance and adequate safety standards has led to the exploration and modification of conventional explosives. In this work, we computationally investigated the structural modification of the 1,1-diamino-2,2-dinitroethene (FOX-7) core by introducing two tetrazole rings on the geminal amino groups, intended to improve the performance and heat of explosion while maintaining lower sensitiveness toward mechanical stimuli. The computed results indicated that the incorporation of tetrazole rings significantly increased the nitrogen content (59%), heat of formation (624 kJ mol⁻¹), detonation velocity (8.9 km s⁻¹), detonation pressure (33.97 GPa), and heat of explosion (4852 kJ kg⁻¹) compared to FOX-7, confirming the effectiveness of structural changes. Additionally, the structure modification of FOX-7 brings a favourable balance between increased energetic output and moderate sensitivity, making it a safer and more efficient candidate for high-performance explosive applications. The computed results underscore the potential of tetrazole-functionalized FOX-7 as a high-density energetic material.