Synthesis and Unexpected Reactivity of a 1,2,4-Triazine derived Azidoxime

The design and synthesis of energetic materials is crucial for the development of new propellants and explosives that have better performance, lower sensitivities, and higher thermal stabilities compared to current materials. To meet these goals, high-nitrogen compounds are commonly targeted as they possess high heats of formation, large densities, and are thermally stable. A class of underexplored high-nitrogen materials are azidoximes. Azidoximes are unique as they contain an energetic azide group, while possessing an improved oxygen balance, yet these species are typically generated in situ and not isolated due to their high sensitivities. This presentation will present the synthesis of a 1,2,4-triazine derived azidoxime. This material was formed in 64% yield over three steps, has a calculated density of 1.746 g•cm^–1, and is less sensitive to impact, spark, and friction, as compared to PETN and RDX. We subjected this azidoxime to acid catalyzed cyclization conditions in an attempt to form its 1-hydroxytetrazole isomer; however, this azidoxime failed to react even after prolonged reaction times with heating. This observation led us to probe the reactivity of this material via electronic structure calculations, electrostatic potential mapping and Hirshfeld surface analyses.