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

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 (rho: 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 (rho: 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.