Enhancement of Energetic Performance through the Construction of Trinitromethyl Substituted β‑Bis(1,2,4-oxadiazole)

Halogen-free substitutions of ammonium perchlorate (AP), which meet the requirements of high density, high performance,
and acceptable stability, have been a subject of scientific research
for many years. In this work, by regrouping atoms in trinitromethyl
substituted bis­(1,2,4-oxadiazole), a novel oxidizer, trinitromethyl
substituted β-bis­(1,2,4-oxadiazole) (3), was designed
and synthesized. It possesses an improved density (ρ = 2.002
g cm–3 at 170 K, ρ = 1.942 g cm–3 at 298 K) and thermal stability (Td =
142.8 °C) in comparison to its regioisomer 5,5′-bis­(trinitromethyl)-3,3′-bi­(1,2,4-oxadiazole)
(E). The properties for 3 were studied by
both experimental and theoretical methods. The high positive oxygen
balance of +7.3% and high specific impulse of 250 s also make compound 3 a promising candidate for an energetic oxidizer.