Expanding the π -conjugate structures: Synthesis of high-energy and insensitive Tricyclic fused energetic material

In order to meet the growing demand for different applications, great efforts have been made to develop new energetic materials with high energy and good safety. Fused cyclic energetic material, a special category of π -conjugate structures containing two or more rings, typically exhibits excellent performance and is currently a key focus of research. In this paper, we have designed and synthesized a new tricyclic, fused energetic material: 5-amino-[1,2,5]oxadiazolo[3,4- e ]tetrazolo[1,5- c ]pyrimidine 1-oxide ( 3 ). The reaction mechanism of the one-step reaction, including nucleophilic substitution and cyclization, has been theoretically investigated. Notably, compound 3 has a high density (1.864 g cm −3 ) at room temperature and good detonation properties ( D v : 8391 m s −1 and P : 28.2 GPa). Compound 3 has a relatively low impact and friction sensitivity ( IS > 40 J, FS > 300 N), and acceptable thermal stability ( T d : 175 °C), demonstrating the great potential of compound 3 as a high-energy, insensitive tricyclic fused energy-containing material.