Triazolo-triazine derivatives outperforming CL-20: computational discovery and substituent engineering for superior energetic materials.

CONTEXT: Triazolo[4,5-d]triazine fused-ring energetic materials exhibit excellent thermal stability and low mechanical sensitivity, but their detonation performance is generally inferior to CL-20. To overcome this limitation, this study utilizes the nitrogen-rich triazolo[4,5-d]triazine fused-ring system as a parent scaffold. By incorporating energetic functional groups-including azido, trinitromethyl, hydrazino, nitro, nitramino, cyano, nitrate ester, and dinitromethyl moieties-we designed 64 novel energetic derivatives across four distinct series (A-D). Furthermore, we systematically investigated the substituent effects on molecular energy, crystal packing, detonation performance, impact sensitivity, and electronic structure, aiming to screen for high-performance energetic candidates. Of the 64 derivatives designed, compounds D6, B8, B6, and D14 demonstrate superior performance with detonation velocities over 9.5 km/s and detonation pressures exceeding 43 GPa, surpassing RDX and HMX and nearing the performance of the benchmark explosive CL-20. D6 (D = 9.68 km/s, P = 43.82 GPa) stands out with superior detonation performance, whereas B6 exhibits the greatest crystal density at 2.0021 g·cm⁻3. These four candidates warrant priority for future experimental synthesis and evaluation. METHODS: Quantum chemical, crystal prediction, and detonation simulations were carried out at the M06-2X/6-311G(d,p) level using Gaussian 16, Materials Studio, and Multiwfn.