Synthesis and Characterization of 2,2'-Dinitramino-5,5'-bi(1-oxa-3,4-diazole) and Derivatives as Economic and Highly Dense Energetic Materials.

2,2'-Dinitramino-5,5'-bi(1-oxa-3,4-diazole) (2) is a new highly energetic material with superior calculated detonation performance in comparison to cyclo-1,3,5-trimethylene-2,4,6-trinitramine (RDX) and penta-erythritoltetranitrate (PETN) and can be prepared by an economical and practical two-step synthesis. The starting material 2,2'-diamino-5,5'-bi(1-oxa-3,4-diazole) (1) is synthesized by the reaction of oxalyl dihydrazide with cyanogen bromide. Nitration of 1 yields the title compound in perfect yield and purity. The combination of its high density of 1.986 g cm-3 , the positive heat of formation (+190 kJ mol-1 ), and a slightly positive oxygen balance (+6.2 %) results in ideal calculated detonation parameters (e.g. detonation velocity 9296 m s-1 ). The sensitivities toward impact and friction can be adjusted by deprotonation and formation of corresponding nitrogen-rich salts, for example, ammonium (3), hydroxylammonium (4), and guanidinium (5) salts.