Exploring the highly dense energetic materials via regiochemical modulation: A comparative study of two fluorodinitromethyl-functionalized herringbone trifuroxans

[Display omitted] •Two novel high-energy regioisomers are synthesized via ingenious construction strategy.•A regioisomer exhibits the highest crystal density among CHNOF compounds reported thus far.•The structure analysis shows how the N-oxide position affects their densities.•This study demonstrates regiochemical modulation could be a powerful tool to enhance the energetic properties. Maximization of the energy capability of energetic materials by organizing energetic moieties into dense arrangements is of great significance. In this study, two novel high-energy regioisomers, 3,4–bis(3–fluorodinitromethylfuroxan-4-yl) furoxan (BFTF-1) and 3,4–bis(4–fluorodinitromethylfuroxan-3-yl) furoxan (BFTF-2), were synthesized by employing controllable synthetic strategy. The constitutional isomers were thoroughly characterized using multinuclear NMR and IR spectroscopy, elemental analysis as well as single-crystal X-ray diffraction. Notably, BFTF-1 shows the highest crystal density (ρ: 2.00 g cm−3, 296 K) among fluorodinitromethyl-functionalized CHNOF compounds reported thus far and outstanding detonation performances (D: 9509 m s−1, P: 42.6 GPa), which are significantly higher than that of BFTF-2 (ρ: 1.91 g cm−3, D: 9196 m s−1). The remarkable differences in inter- and intra-molecular interactions of BFTF-1 and BFTF-2 provide unequivocal evidence that the synergistic actions between fluorodinitromethyl and furoxan play a key role in crystal stacking, eventually causing a significant difference in density. This research demonstrates that regiochemical modulation via reasonable design could be a powerful tool to enhance the density and detonation property in the development of new energetic materials.