Increasing the limits of energy and safety in tetrazoles: dioximes as unusual precursors to very thermostable and insensitive energetic materials

Abstract

Donor–acceptor hydrogen (H)-bonding contributes to good temperature resistance for energetic compounds. Now we report a strategy which maximizes donor–acceptor H-bonding sites in the construction of new energetic compounds. The straightforward synthesis of 1,2-di(1H-tetrazol-5-yl) ethane-1,2-dione dioxime (2), as an unusual energetic precursor to highly thermostable and insensitive energetic materials was achieved in four steps from glyoxal (40% in water). The oxime group in compound 2 acts as a H-bond donor and acceptor and its salt formation reaction with hydroxylamine maximizes H-bonding interactions. Dihydroxylammonium 1,2-di(1H-tetrazol-5-yl) ethane-1,2-dione, 3, exhibits high thermal stability (285 °C) and insensitivity to impact (>60 J) and friction (>360 N) owing to the presence of donor–acceptor H-bonds and wave-like crystal packing. It has high heat of formation (524.3 kJ mol⁻¹) and high detonation velocity of 9114 ms⁻¹. Compound 3 exhibits high safety, ultrahigh power and good compatibility, which make it a potential high-energy-density material for practical use.