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High-energy density materials represent a significant class of advanced materials and have been the focus of energetic materials community. The main challenge in this field is to design and synthesize energetic compounds with a highest possible density and a maximum possible chemical stability. Here we show an energetic compound, [2,2′-bi(1,3,4-oxadiazole)]-5,5′-dinitramide, is synthesized through a two-step reaction from commercially available reagents. It exhibits a surprisingly high density (1.99 g cm−3 at 298 K), poor solubility in water and most organic solvents, decent thermal stability, a positive heat of formation and excellent detonation properties. The solid-state structural features of the synthesized compound are also investigated via X-ray diffraction and several theoretical techniques. The energetic and sensitivity properties of the explosive compound are similar to those of 2, 4, 6, 8, 10, 12-(hexanitrohexaaza)cyclododecane (CL-20), and the developed compound shows a great promise for potential applications as a high-energy density material.

Over the past century, the search for lead-free, environmentally friendly initiating substances has been a highly challenging task in the field of energetic materials. Here, an organic primary explosive featuring a fused-ring structure, 6-nitro-7-azido-pyrazol[3,4-d][1,2,3]triazine-2-oxide, was designed and synthesized through a facile two-step reaction from commercially available reagents. This organic initiating substance meets nearly all of the stringent criteria of environmentally friendly primary explosives for commercial applications: it is free of toxic metals and perchlorate, has a high density, high priming ability, unusual sensitivities towards non-explosive stimuli, excellent environmental resistance, decent thermal stability, high detonation performance, satisfactory flowability and pressure durability, and is low-cost and easy to scale-up. These combined properties and performance measures surpass the current and widely used organic primary explosive, DDNP. The fused-ring organic primary explosive reported herein may find real-world application as an initiating explosive device in the near future.

The experimental detection and synthesis of pentazole (HN ) and its anion (cyclo-N ) have been actively pursued for the past hundred years. The synthesis of an aesthetic three-dimensional metal-pentazolate framework (denoted as MPF-1) is presented. It consists of sodium ions and cyclo-N anions in which the isolated cyclo-N anions are preternaturally stabilized in this inorganic open framework featuring two types of nanocages (Na N and Na N ) through strong metal coordination bonds. The compound MPF-1 is indefinitely stable at room temperature and exhibits high thermal stability relative to the reported cyclo-N salts. This finding offers a new approach to create metal-pentazolate frameworks (MPFs) and enables the future exploration of interesting pentazole chemistry and also related functional materials.

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