Heterocyclic-based nitrodicyanomethanide and dinitrocyanomethanide salts: a family of new energetic ionic liquids

Twelve novel energetic salts 1a-f and 2a-f with nitrodicyanomethanide and dinitrocyanomethanide anions paired with 1,5-diamino-4-methyltetrazolium, 1,4-dimethyl-5-aminotetrazolium 1,4,5-trimethyltetrazolium, 1-methyl-4-amino-1,2,4-triazolium, 1,4-dimethyltriazolium, and 1,3-dimethylimidazolium have been prepared through metathesis reactions of equivalent silver(I) salts with corresponding iodide salts in acetonitrile. Key physical properties, such as melting point, thermal stability and density, were measured. The relationship between their structures and these properties was determined. The structures of 1,5-diamino-4-methyltetrazolium-based salts 1a and 2a were further confirmed by single-crystal X-ray analysis. The densities and standard enthalpies of formation for these energetic salts were calculated. All of the salts possess higher enthalpies of formation than the nitrate analogues.