Oxygen Enrichment of Fused Tricyclic Ring by Incorporating with Trinitromethyl Group

Nitrogen-rich fused heterocycles are promising backbones for high-energy-density materials but often suffer from negative oxygen balance. Herein, the oxygen-rich trinitromethyl group was introduced into a fused pyrazolo[1,5-a][1,2,4]triazolo[1,5-c][1,3,5]triazine framework to improve oxygen balance and energetic performance. The oxygen enrichment of fused tricyclic ring results compound 7 with a high density of 1.86 g cm⁻³ and positive oxygen balance of +7.7%, improved detonation velocity and pressure of 8856 m s⁻¹ and 34.3 GPa, respectively.