Synthesis and thermochemical properties of NF2-containing energetic salts

Ammonium, 1,5-diamino-4-methyl-tetrazolium and 4-amino-1-methyl-triazolium salts of 5-difluoroaminodifluoromethyl-tetrazolate (TA-CF₂NF₂) were prepared by metathesis reactions of silver 5-difluoroaminodifluoromethyl-tetrazolate and the corresponding iodides. All are thermally stable to ∼150 °C. The ammonium salt has a density of 1.88 g cm⁻³. The combination of the CBS-4 method and isodesmic bond separation reactions was found to be an economical and reliable method to estimate heats of formation for polyfluorinated molecules. The standard heats of formation () of ammonium 5-difluoroaminodifluoromethyl-tetrazolate was calculated to be −53.13 kcal mol⁻¹ using the CBS-4 method. While its detonation pressures (P) and velocities (D) were estimated using Cheetah 4.0: P = 28.78 GPa; D = 8490 m s⁻¹; detonation properties for 1,5-diamino-4-methyl-tetrazolium salts of 5-difluoroaminomethyltetrazolate (TA-CH₂NF₂), 5-difluoroaminotetrazolate (TA-NF₂) and 5-difluoroaminodinitromethyl-tetrazolate (TA-C(NO₂)₂NF₂) are also compared based on predicted densities and computed heats of formation.