Computational Investigation on the Structure and Performance of Novel 4,7-Dinitro-furazano-[3,4-d]-pyridazine Derivatives

Seven novel energetic 4,7-dinitro-furazano-[3,4-d]-pyridazine derivatives were designed, and their optimized structures and performances were studied by density functional theory (DFT) at B3LYP/6-311g(d,p) level. The detonation performances were estimated by the Kamlet-Jacobs equations. The results show that these compounds have high crystal densities (1.8181.925 g·cm−3), detonation velocities (8.51-9.56 km·s−1) and detonation pressures (32.28-41.70 GPa). The bond dissociation energies (BDEs) of the weakest bond (N–O bond) vary from 70.889 kJ·mol−1 to 173.283 kJ·mol−1, and some of them exhibit higher BDEs than that of RDX (N–NO2 bond, 149.654 kJ·mol−1) and HMX (N–NO2 bond, 154.905 kJ·mol−1). M4 and M5 exhibit similar and higher detonation performance than RDX (8.81 km·s−1, 34.47 GPa). The detonation performance of M7 (9.56 km·s−1, 41.70 GPa) even surpasses that of HMX (9.10 km·s−1, 39.00 GPa). Otherwise, the specific impulse values of M1-M7 (266-279 s) outperform HMX (266 s) by 0-13 s, which indicates that M1-M7 may show better performance as monopropellants. It is concluded that density, heat of formation, stability, detonation performance and specific impulse of the designed compounds depend on the position and number of the N→O oxidation bonds.