Synthesis and properties of novel 1,2,5-oxadiazole-based nitramide salts with fluorodinitromethyl as an energetic moiety

To develop oxidizers with superior energy density, this study presents the design and synthesis of three energetic salts based on N-(4-fluorodinitromethyl-1,2,5-oxadiazol-3-yl)nitramide. The structures of these compounds were comprehensively characterized by Fourier-transform infrared spectroscopy (FT-IR), high-resolution mass spectrometry (HRMS), single-crystal X-ray diffraction (SC-XRD), and multinuclear NMR spectroscopy (13C, 19F). Their thermal behaviors were evaluated using simultaneous thermogravimetric-differential scanning calorimetry (TG-DSC). The results indicate that the thermal decomposition temperatures for the potassium salt, ammonium salt, and hydroxyammonium salt are 143.2°C, 165.4°C, and 140.5°C, respectively. The ammonium salt exhibits a density of 1.75 g/cm3, an enthalpy of formation of 37.6 kJ/mol, a detonation velocity of 8712 m/s, and a detonation pressure of 32.1 GPa. In comparison, the hydroxyammonium salt has a higher density (1.89 g/cm3) and enthalpy of formation (65.0 kJ/mol), along with superior detonation performance (detonation velocity: 9252 m/s, detonation pressure: 38.1 GPa). Notably, the energetic characteristics of the hydroxyammonium salt are comparable to those of HMX, underscoring its high energetic potential as novel oxidizer.

为开发具备优异能量密度的氧化剂，本研究设计并合成了三种基于N-(4-氟二硝甲基-1,2,5-噁二唑-3-基)硝酰胺的含能盐。上述化合物的结构通过傅里叶变换红外光谱（Fourier-transform infrared spectroscopy, FT-IR）、高分辨质谱（high-resolution mass spectrometry, HRMS）、单晶X射线衍射（single-crystal X-ray diffraction, SC-XRD）以及多核核磁共振波谱（multinuclear NMR spectroscopy, 13C、19F）进行了全面表征。采用同步热重-差示扫描量热法（simultaneous thermogravimetric-differential scanning calorimetry, TG-DSC）对其热行为展开评估。结果显示，钾盐、铵盐与羟胺盐的热分解温度分别为143.2℃、165.4℃与140.5℃。其中铵盐的密度为1.75 g/cm³，生成焓为37.6 kJ/mol，爆速达8712 m/s，爆压为32.1 GPa。相较之下，羟胺盐拥有更高的密度（1.89 g/cm³）与生成焓（65.0 kJ/mol），同时具备更优异的爆轰性能：爆速9252 m/s，爆压38.1 GPa。值得注意的是，羟胺盐的含能特性与奥克托今（HMX）相当，凸显了其作为新型氧化剂的高应用潜力。