Study on the synthesis of 2-fluoro-2,2-dinitroethyl esters as a potential melt cast matrix in explosive charges

Abstract

Herein, a series of esteryl-bridged energetic compounds were prepared using a simple and efficient esterification approach. All the compounds were fully characterized by IR spectroscopy, multinuclear NMR spectroscopy, mass spectrometry, elemental analysis, thermogravimetric analysis (TG), and differential scanning calorimetry (DSC). Structures of 1 and 4 were further confirmed by single crystal X-ray diffraction. Energetic performance was evaluated by EXPLO5 based on the measured densities and calculated heats of formation (Gaussian 09). These fluorodinitroethyl esters have good thermal stabilities (190.7–208.3 °C) and high densities (1.81–1.90 g cm⁻³). Detonation pressures and velocities of 1–5 fall in the range of 27.4–36.6 GPa and 7870–8459 m s⁻¹, respectively. Sensitivity data based on impact and friction tests show that these compounds are insensitive (IS = 27.6–40 J; FS > 360 N). Moreover, two of the representative compounds 1 and 4 exhibit the desired melting points (1: 85.0 °C; 4: 94.7 °C) as the ideal melt cast explosives, relatively high detonation properties (D = 8459, 8196 m s⁻¹; P = 36.6, 29.8 GPa), as well as relatively low sensitivities (IS = 30.5, 27.6 J; FS > 360 N).