Solid crystalline explosives

In spite of intensive research for many decades, the theory of combustion and explosion has not been able to explain the phenomenom of sensitivity of solid crystalline explosives to shock and fiiction. The phenomena is well known, and in practice often used (for the ignition of solid explosives by shock or by a short dynamical action), but is still waiting for a theoretical explanation. The thermal approach was used to address the problem mechanical action (shock, fiiction) is transformed into... 

Saalfrank, R. W. etal., Angew. Chem. (Intern. Ed.), 1987, 26, 1161 (footnote 14) The crystalline solid decomposes explosively around 70°C, so working scale was limited to 0.5 g. 

Tetramminecopper(II) azide, [(NH3)4Cu ] (N3)2, the azide salt of the well-known tetramminecopper cation, is a blue, crystalline solid with explosive properties. It decomposes within a few days by losing two NH3, to form diazidodiamminecopper (see below). In contact with water the same reaction occurs rapidly. The salt is made either by dissolving the normal copper azide in liquid ammonia and evaporating the blue solution [183], or by exposing Cu(N3)2 to dry ammonia gas [189]. 

Hydroxylamine is a white crystalline explosive solid and thermally unstable. 

The pure tribromide and triodide are unknown but their ammoniates have been prepared by the action of the appropriate halogen on ammonia. The tribromide, NBr bNUj, is a purple solid which decomposes explosively above 200K. The iodide, Nl3. NH3, is a black explosive crystalline solid, readily hydrolysed by water. 

Mechanical treatment alone may be sufficient to induce significant decomposition such processes are termed mechanochemical or tribo-chemical reactions and the topic has been reviewed [385,386]. In some brittle crystalline solids, for example sodium and lead azides [387], fracture can result in some chemical change of the substance. An extreme case of such behaviour is detonation by impact [232,388]. Fox [389] has provided evidence of a fracture initiation mechanism in the explosions of lead and thallium azide crystals, rather than the participation of a liquid or gas phase intermediate. The processes occurring in solids during the action of powerful shock waves have been reviewed by Dremin and Breusov [390]. 

An unstable and explosive crystalline solid, formally a nitro-oxime. 

Decomposes in solution at 0°C but can be handled, with caution even sublimed, as an explosive crystalline solid, m.p. 66°C. 

Schel, S. A. etal., J. Mol. Struct., 1986, 147(3 -4), 203 -215 Although it is highly explosive, like other polyunsaturated azides, it was possible to record spectral data under the following conditions gaseous electron diffraction IR spectra of matrix-isolated species in argon at 15°K of amorphous and crystalline solids at 90°K and Raman spectra of the liquid at 240°K. 

Severe explosions occurred when the cold crystalline solid was allowed to warm to ambient temperature. Normal manipulation of dilute solutions appears feasible, but the solid must be handled at lowest possible temperatures with full safety precautions. The 4-isomer appears much more stable. 

Hafner, K. etal., Org. Synth., 1964, 44, 102 The crystalline solid is an impact- and friction-sensitive explosive and must be handled with precautions. These include use of solvent-moist material and storage in a corked rather than glass-stoppered vessel. 

In view of the ready commercial availability and apparent stability of the hexahy-drate, it is probable that the earlier report of explosion on impact, and deflagration on rapid heating [1] referred to the material produced by partial dehydration at 100°C, rather than the hexahydrate [2], The caked crystalline hydrated salt, prepared from aqueous perchloric acid and excess cobalt carbonate with subsequent heated evaporation, exploded violently when placed in a mortar and tapped gently to break up the crystalline mass, when a nearby dish of the salt also exploded [3]. Subsequent investigation revealed the probable cause as heating the solid stable hexahydrate to a temperature ( 150°C) at which partial loss of water produced a lower and endothermic hydrate (possibly a trihydrate) capable of explosive decomposition. This hazard may also exist for other hydrated metal perchlorates, and general caution is urged [4,5],... 

Colorless crystalline solid with an odor like garlic or bitter almonds detectable at 0.001-0.0005 ppm. Undergoes considerable decomposition when explosively disseminated. 

Tetryl (C7H5N508) is a pale yellow crystalline solid. It is moderately sensitive to initiation by friction and percussion and is used in the form of pressed pellets as primers for explosive compositions that are less sensitive to initiation. It is slightly more sensitive than picric acid and considerably more sensitive than TNT. In the early 1900s, tetryl was used as base charges for blasting caps but now has been replaced by PETN and RDX. During World War II, tetryl was used as a component of explosive mixtures. 

Cyclotetramethylenetetranitramine or HMX (C4H8N808) is a white crystalline solid with a melting point of 285°C. HMX is superior to RDX in that its ignition temperature is higher and its chemical stability is greater. However, its explosive power is... 

TATB or 1,3,5-triamino-2,4,6-trinitrobenzene (C6H6N6Oe) is a yellow-brown crystalline solid that has excellent thermal stability and is known as a heat-resistant explosive. TATB has a decomposition point of 325°C. Its molecular arrangement provides lubricating and elastic properties. 

Pentaerythritol tetranitrate (PETN) is a colorless crystalline solid that is very sensitive to initiation by a primary explosive. It is a powerful secondary explosive that has a great shattering effect. It is used in commercial blasting caps, detonation cords, and boosters. PETN is not used in its pure form because it is too sensitive to friction and impact. It is usually mixed with plasticized nitrocellulose or with synthetic rubbers to form PBXs. The most common form of explosive composition containing PETN is Pentolite, a mixture of 20 to 50% PETN and TNT. PETN can be incorporated into gelatinous industrial explosives. The military has in most cases replaced PETN with RDX because RDX is more thermally stable and has a longer shelf life. PETN is insoluble in water, sparingly soluble in alcohol, ether, and benzene, and soluble in acetone and methyl acetate. 

Hexanitrostilbene or HNS (C14H6N6012) is a heat-resistant yellow crystalline solid explosive. HNS is also resistant to radiation, insensitive to electric sparks, and less sensitive to impact than tetryl. It is used in heat-resistant booster explosives and has been used in stage separations in space rockets and for seismic experiments on the moon. Its melting temperature is 316 °C.12... 

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