Energetic materials with fluorinated four-membered heterocyclic ring: 3,3′-difluoroazetidine (DFAZ) salts†
Abstract
3,3′-Difluoroazetidinium (DFAZ) possesses a high-tensile four-membered ring and fluorine atoms, which contributes to the specific impulse, detonation pressure and detonation velocity. High-density energetic salts that contain oxygen-rich anions and cations were synthesized. All of the salts were fully characterized by IR spectroscopy, single-crystal X-ray diffraction, elemental analysis, differential scanning calorimetry (DSC) as well as impact and friction sensitivity. Their detonation properties were calculated according to the densities and heats of formation. The results showed that compared to ADN, they all had a relatively high density and low impact sensitivity. The specific impulse of almost all of the salts were higher than that of the propellant component, ammonium dinitramide (ADN, Isp = 202 J). Moreover, the 3,3′-difluoroazetidinium nitroformate salt had the highest specific impulse and was relatively more stable. It is possible to obtain energetic cations with good properties by combining four-membered high-tension rings with fluorine atoms.