Elucidation of the influence of trinitro-diazinotriazine isomerism on the energetic properties and stability: Insights from DFT approach

• Emphasizing the importance of isomeric energetic materials for tuning energy content and stability. • Reducing trade-off between performance-stability by combining nitrogen-rich framework with nitro groups . • Designed trinitro-diazinotriazines exhibit superior detonation properties (D > 8.7 km/s, P > 34 GPa). • Revealing the significant role of aromatic, planar, conjugated and nitrogen-rich backbone in explosive design. The exploration of isomeric energetic molecules with high nitrogen content and the examination of their structure–property relationships remains compelling areas of interest within the field of energetic materials. Energetic isomers comprising the same molecular composition but distinct molecular structures potentially lead to notable variations in performance and properties. This study focused on designing and evaluating different forms of diazinotriazine using two molecular compositions: C 5 H 3 N 5 and C 5 N 8 O 6 , aiming to generate various isomeric structures and to guide the rational design of new molecules. The electronic configurations, energetic properties, and sensitivity prediction of the optimized structures were investigated using the M06-2X/def2-TZVPP level of theory. The trinitro-diazinotriazine isomers exhibit high heat of formation (>486 kJ/mol), high detonation properties (D > 8.7 km/s, P > 34 GPa), high density (>1.81 g/cm 3 ), and better thermal stability (BDE > 230 kJ/mol) making them promising explosive contenders. Among the designed diazinotriazine backbones, the pyridazine-1,2,3-triazine framework is favourable for the heat of formation and detonation properties. The heats of formation, detonation velocity, pressure, and heats of detonation of A4 and B4 outperform the other trinitro-diazinotriazine isomers.