Unsymmetrical Functionalization of Bis-1,2,4-triazoles Skeleton: Exploring for Promising Energetic Materials

Unsymmetrical functionalization of bis-1,2,4-triazoles was attempted, and a series of nitrogen/oxygen-rich energetic materials were designed and synthesized in this study. Compared with previously reported symmetrical bis-1,2,4-triazole derivatives (iv and v), both unsymmetrically functionalized bis-1,2,4-triazole derivatives (3 and 7) in this work possess improved safety properties (impact sensitivities: 22 J (3) and 11 J (7); friction sensitivities: >360 N (3) and 250 N (7)). Meanwhile, the detonation performance of 3 was apparently improved compared with the C-nitrated compound iv. These features indicate that unsymmetrical functionalization would be a favorable strategy to construct energetic materials with both high energy and safety. Moreover, N-trinitromethyl-functionalized compound 5 possesses high density (1.92 g cm–3), positive oxygen balance (+25.1%), and desirable detonation performance similar to HMX, with higher specific impulse (Isp = 265.1 s) than ADN, suggesting its superiority as a highly energetic oxidizer.