Polyazido-methyl Derivatives of Prominent Oxadiazole and Isoxazole Scaffolds: Synthesis, Explosive Properties, and Evaluation
Lukas Bauer, Maximilian Benz, Thomas M. Klapötke, Tobias Lenz, Jörg Stierstorfer
Abstract
Recently, different nitrato-methyl-substituted oxadiazoles have been described as potential melt-cast explosives. In this work, corresponding N–O heterocyclic-based compounds with azido-methyl functionalities were synthesized. In each case, the explosophoric azide group is inserted by chlorine–azide exchange during the last synthetic step. All synthesized compounds show interesting characteristics for various applications in the field of energetic materials as energetic plasticizers or as melt-cast explosives. The compounds were extensively analyzed by IR, EA DTA, and multinuclear NMR spectroscopy. Furthermore, the solid compounds 4,4′,5,5′-tetrakis(azidomethyl)-3,3′-bisisoxazole (2) and 3,3′-bis(azidomethyl)-5,5′-bis(1,2,4-oxadiazole) (4) were characterized using X-ray diffraction. In addition, the sensitivities toward friction and impact were determined with BAM standard techniques, and the energetic performances of all synthesized azido-methyl compounds were calculated using the EXPLO5 code. The properties were compared to recently published, structurally related compounds.