Host–guest energetic materials: a promising strategy of incorporating small insensitive molecule into the lattice cavities of 2,4,6,8,10,12-hexanitrohexaazaisowurtzitane to enhance the safety on the premise of maintaining the excellent energy density

A novel HNIW-MA host–guest explosive was constructed by embedding the mall molecules into the lattice cavities of HNIW, and it enhances the safety on the premise of maintaining its energy density.

Smart Host-Guest Energetic Material Constructed by Stabilizing Energetic Fuel Hydroxylamine in Lattice Cavity of 2,4,6,8,10,12-Hexanitrohexaazaisowurtzitane Significantly Enhanced the Detonation, Safety, Propulsion, and Combustion Performances

The host-guest inclusion strategy has become a promising method for developing novel high-energy density materials (HEDMs). The selection of functional guest molecules was a strategic project, as it can not only enhance the detonation performance of host explosives but can also modify some of their suboptimal performances. Here, to improve the propulsion and combustion performances of 2,4,6,8,10,12-hexanitrohexaazaisowurtzitane (HNIW), a novel energetic-energetic host-guest inclusion explosive was obtained by incorporating energetic rocket fuel, hydroxylamine (HA), into the lattice cavities of HNIW. Based on their perfect space matching, the crystallographic density of HNIW-HA was determined to be 2.00 g/cm³ at 296 K, which has reached the gold standard regarding the density of HEDMs. HNIW-HA also showed higher thermal stability (T_d = 245.9 °C) and safety (H₅₀ = 16.8 cm) and superior detonation velocity (D_V = 9674 m/s) than the ε-HNIW. Additionally, because of the excellent combustion performance of HA, HNIW-HA possessed higher propulsion performances, including combustion speed (S_C = 39.5 mg/s), combustion heat (Q_C = 8661 J/g), and specific impulse (I_sp = 276.4 s), than ε-HNIW. Thus, the host-guest inclusion strategy has potential to surpass the limitations of energy density and suboptimal performances of single explosives and become a strategy for developing multipurpose intermolecular explosives.

Electronic structure, reactivity, and Hirshfeld surface analysis of carvone

The density functional theory (at the B3LYP level using 6-311++G(2d,2p) basis set) was used for the investigation of the geometry and electronic properties of the carvone. The electronic properties and chemical activity of the titled compound were investigated by means of several theoretical approaches, molecular electrostatic potential surface, natural bond orbital, and frontier molecular orbital analyses. It was established that the oxygen atom in the structure characterized the electrophilic reactivity; the positive regions are localized on the hydrogen atoms, which can be considered as possible sites for nucleophilic attack. A detailed analysis of the intermolecular interactions via Hirshfeld surface analysis and fingerprint plots revealed that the carvone structure is stabilized mainly by the formation of O. . .H/H. . .O hydrogen bonds. However, close contacts were established between C. . .H/H. . .C and H. . .H contacts.

Energetic materials with fluorinated four-membered heterocyclic ring: 3,3′-difluoroazetidine (DFAZ) salts

Fluorine atoms and four-membered rings form 3,3′-difluoroazetidinium (DFAZ) salts, which have a better detonation property than ammonium dinitramide (ADN).