Design and Performance Evaluation of Nitrogen-Rich Bis-Six-Membered Fused Ring Energetic Materials via Density Functional Theory

Context Density functional theory (DFT) calculations at the M06-2X/def2-TZVP level were employed to design bis-six-membered nitrogen-rich fused ring energetic materials. Six neutral derivatives ( I-2-4 , I-3-4 , I-3-5 , II-2-4 , II-3-4 and II-3-5 ) achieved energy densities exceeding 2.0 g/cm ³ , with energetic salts reaching unprecedented values up to 3.3 g/cm ³ . Non-covalent interaction isosurfaces quantified van der Waals forces in crystal packing, while decomposition pathway simulations for II-3-2 identified a low O-NO ₂ BDE (20.24 kcal/mol) coexisting with high thermal stability ( = 765.3 ^o C), governed by autocatalytic kinetics ( = 24.7 kcal/mol and = 8.44 kcal/mol). The DFT-derived performance matrix ( > 2.02 g/cm ³ , > 600°C, HOFs > 3500 kJ/mol) provides a transferable protocol for balancing energy and safety in molecular modeling of advanced energetics. Method The DFT based geometric optimization and frequency analyses of the designed molecules were determined using M06-2x/def2-TZVP method at Gaussian 09 package suite of programs. The heats of formation (HOF) for all molecules were obtained using an atomization reaction. The kinetic energy (), electrostatic potential (ESP) and other related calculations were computed using Multiwfn_3.8_dev software. The visualization of the weak interaction between dimers was accomplished using VMD 1.9.3 program.