Nitroaminofurazans with Azo and Azoxy Linkages: A Comparative Study of Structural, Electronic, Physicochemical, and Energetic Properties

The
structural, electronic, and physicochemical properties of 4,4′-bis­(nitramino)­azofurazan
and 4,4′-bis­(nitramino)­azoxyfurazan as high-energy density
materials were compared. In addition, a new family of nitrogen-rich
energetic salts based on these two nitroaminofurazans were synthesized
and fully characterized. On the basis of experimental evidence and
theoretical calculations, 4,4′-bis­(nitramino)­azoxyfurazan and
its ionic derivatives were found to exhibit higher detonation velocities
and pressures, and higher densities than their azofurazan analogues
which supports the added value of introduction of the N-oxide moiety
into energetic materials. The solid state features for the two nitroaminofurazans
were studied in detail by X-ray diffraction and noncovalent interaction
index which identify additional hydrogen-bonding and extensive edge-to-face
π–π stacking interactions arising from the presence
of the azoxy N-oxide.