Molecular perovskite high-energetic materials

Abstract

Since the black powder, the first known explosive, was discovered by ancient Chinese in the seventh century, people have been finding powerful, stable, reliable and low-cost energetic materials for military equipment and civil industry. To obtain a better explosive performance, an efficient strategy is to load unstable chemical bonds [1][2][3], as well as to combine fuel with oxidizer components in a proper ratio for achieving sufficient combustion and rapid detonation [4][5][6]. An effective way is to incorporate fuel and oxidizer properties into a single molecule [7], as demonstrated by a series of classical organic nitro group/nitrogen-rich molecules, such as trinitrotoluene (TNT), pentaerythritol tetranitrate (PETN), cyclotrimethylene trinitramine (RDX), cyclotetramethylene tetranitramine (HMX), hexanitrohexaazaisowurtzitane (CL-20) and octanitrocubane (ONC) (Fig. S1). Loading more nitro groups and higher structural tension into a single molecule does improve explosive performance, but usually leads to complicated and not cost-effective synthetic procedures. By a trade-off of detonation performance and cost, HMX is regarded as the best military high-energetic explosives nowadays [7], although it is neither the most powerful one nor the cheapest one.Parallel to the intensive studies on molecule engineering on the backbone of nitrogen-rich organic energetic molecules [8,9], the exploration of advanced energetic materials extends to the crystal engineering on their energetic co-crystals [10-13], energetic salts [14][15][16][17][18][19][20], as well as coordination polymers or metal-organic frameworks [21][22][23][24][25][26][27]. The essential strategy is to control the intermolecular packing/linkage of the energetic organic fuel and oxidizer components in crystals by non-covalent interactions to modify/enhance the explosive performance and/or to reduce the sensitivity to a practicable level. However, for a specific energetic molecular component, it is highly challenging to predict/engineer the crystal structure of its co-crystals, salts, or metal-organic frameworks [10], and the examples with good detonation performance, high stability and low cost are still scarce.Here we present a promising solution, i.e., assembly of both low-cost organic fuel and oxidizer components into a closely packed, high-symmetry ternary compounds (vide infra), to achieve advanced energetic materials with a nice combination of high explosive power, high stability, and low cost. The presented materials belong to the so-called molecular perovskites [28] with a general formula of ABX 3 , which topologically mimic the cubic structure of the very well-known inorganic perovskites, the simplest high-symmetry structure for ternary compounds, but have at least one organic molecular component (usually A component). Recently, molecular perovskites have attracted growing attention, as illustrated by the extensive studies on methyl-ammonium lead iodide for high performance solar cells [29][30][31][32], and the phase transitions together with the ...

Metal‐Free Organic Halide Perovskite: A New Class for Next Optoelectronic Generation Devices

“…Chen et al first reported that DABCONH 4 (ClO 3 ) 4 demonstrated higher decomposition temperature, heat, and pressure compared to common high explosives. [31] Zhou et al, based on thermal analysis, suggested that the decomposition temperature of DABCONH 4 (ClO 3 ) 4 was determined by the inorganic NH 4 (ClO 4 )-based cage structure with the A cation being trapped in this cage. [32] Deng et al mixed DABCONH 4 (ClO 4 ) 3 with graphene as a composite and found that graphene improved the combustion properties of the DABCONH 4 (ClO 4 ) 3 .…”

Room-temperature ferroelectric and ferroelastic orders coexisting in a new tetrafluoroborate-based perovskite

“…[23][24][25][26][27][28][29] For instance, by employing the tetrahedral perchlorate ion (ClO 4 − ), we recently constructed a large family of molecular perovskites being promising practicable high-energetic materials. [30][31][32] Similarly, as another well-known tetrahedral ion, tetrafluoroborate (BF 4 − ) catches increasing attentions with an expectation to serve as bridging ligand for constructing molecular perovskites. Since the first tetrafluoroborate-based perovskite, (H 2 dabco)(NH 4 )(BF 4 ) 3 (H 2 dabco 2+ = 1,4-diazabicyclo[2.2.2]octane-1,4-diium), was reported by Liu et al in 2011, 33 the efforts to date have added five instances.…”

Unique Freezing Dynamics of Flexible Guest Cations in the First Molecular Postperovskite Ferroelectric: (C 5 H 13 NBr)[Mn(N(CN) 2 ) 3 ]

“…[1][2][3][4] By topologically mimicking perovskite structure via diverse molecular components, molecular perovskites (also known as organic-inorganic hybrid perovskites) with a general formula of ABX 3 (where A and B are cations and X is an anion), have exhibited exotic properties that are generally hard to achieve with inorganic materials, such as flexible photovoltaics, 5,6 flexible ferroelectrics, 7,8 and unique energetic properties. 9,10 Moreover, the advantages of mechanical flexibility, environmentally benign synthesis, and easy processing enable molecular perovskites to be promising alternatives for use in next-generation flexible devices, and thus making these materials an important research topic in modern material science. 7,[11][12][13] In view of structural topology (Figure 1), ABX 3 -type perovskites have three typical subclasses that are assigned based on the linkage of the BX 6 octahedra: cubic perovskite, consisting of corner-shaped octahedra; [14][15][16] postperovskite, consisting of both edgeand corner-shared octahedral, and hexagonal perovskite, consisting of face-shared octahedra.…”