Pursuing Heat-resistant and Insensitive Energetic Materials by Constructing Imino Bridged Conjugated Planar Structures

Developing insensitive heat-resistant energetic materials is currently a significant challenge in the research of energetic materials. In this study, two heat-resistant energetic materials (compounds 3 and 4) were designed and prepared by incorporating imino bridged (−NH−) the fused ring of pyrazolo[1,5-a]pyrimidine. All the newly synthesized compounds exhibit excellent thermal stabilities (Td: 316.5−343.9 °C) and good detonation performances (D: 8183−8206 m s-1), as well as satisfactory sensitivities (IS > 40 J, FS > 360 N). These remarkable stabilities are attributed to the π-conjugated planar structures and strong weak interactions in crystals. The comprehensive performances of compound 4 (Td: 343.9 °C, D: 8183 m s-1, IS > 40 J, FS > 360 N) are superior to those of the widely used heat-resistant explosive 2,2′,4,4′,6,6′-hexanitrostilbene (HNS) (Td: 318 °C, D: 7612 m s-1, IS: 5 J, FS: 240 N), indicating its great potential to be used as heat-resistant and insensitive energetic materials.