Explosion boron nitride

Mixtures of boron or carbon with this peroxide are explosive. Boron nitride becomes incandescent. 

Boron nitride exists in many different structures due to the special bonding behaviors of boron and nitrogen. Although the most well-defined crystallographic structures are hexagonal BN (h-BN), cubic BN (c-BN), and wurtzitic BN (w-BN), other crystalline structures, such as explosion boron nitride (e-BN) and ion beam-deposited boron nitride (i-BN) [124—135] and amorphous BN (a-BN) [136,137] also exist. 

With boron there is immediate ignition with fluorine sometimes followed by an explosion. Boron oxide becomes incandescent and so does boron nitride. 

Interaction of I2 with concentrated NH3 solution at room temperature gives black crystals of (NI3-NH3) , n = 1, 3, 5, that are explosive when dry. The crystals have zigzag chains of NI4 tetrahedra sharing comers with NH3 molecules linking the chains together. Pure NI3 has been made as red-black explosive, volatile crystals by interaction of boron nitride with IF in CFC13.73... 

Fig. 9.1 An example of reconstructive phase transition transformation of hexagontil boron nitride (h-BN) into cubic boron nitride (c-BN) is impossible without complete atomization of the parent solid (here achieved by detonating a mixture of BN and an explosive). The coordination number changes from 3 to 4...

The above-mentioned phase transitions conform to the Le Chatelier principle, the sample volume decreasing under high pressure. They are not basically different Irom those observed in the static method, under conditions of thermodynamic equilibrium. There is, however, a class of anomalous phase transitions, which occur only in dynamic experiments and in which the shock compression gives rise to lower densities. The first of such phases was obtained in 1965 by shock treatment of the turbostratic BN [224] the new phase differed from both the graphite-Uke (/i-BN) like (c-BN) polymorphs of boron nitride and was named E-BN (E standing for the explosion phase ). Later, it appeared that the lattice parameters of E-BN are nearly identical to one of the phases of fullerene Ceo [225, 226], viz. a = 11.14, ft = 8.06, c = 7.40 A for E-BN, cf. a= 11.16, = 8.17, c = 7.58 A for Qo, with similar densities of 2.50 g/cm. Thus, the BN-fullerene was obtained by explosion (though not recognized as such) some 25 years before the carbon fuUerene was identified. Later on. 

Sato, T., Ishii, T., and Setaka, N. (1982) Formation of cubic boron nitride from rhombohedral boron nitride by explosive shock compression, f Am. Ceram. Soc.,... 

The use of reductive (Wurtz) coupling of borazine rings by combination of B-haloborazines with Group 1 metals has also been explored. This approach has recently been reexamined by Shore who reported tiiat trichloroborazine and Cs metal react explosively at 125°C with formation of a insoluble, perhaps polymeric, solid some of which has a tubular morphology. Most significantly, the tubular structure is retained in the final boron nitride pyrolysis product... 

The B-N system is accepted ITom [2003Rec]. Only one intermediate phase BN exists in this system. Boron nitride has four crystalline stractural modifications cubic (cBN), wurtzite (wBN), hexagonal (ABN) and rhombohedral (rBN). Except for that, there are two other ordered BN phases EBN, obtained by explosion (E) of a mixture of ABN and aBN, compressed ABN attributable to a monoclinic lattice distortion of ABN and two disordered BN phases turbostratic BN (tBN) and amorphous BN (uBN). 

Ignition or explosive reaction with metals (e.g., aluminum, antimony powder, bismuth powder, brass, calcium powder, copper, germanium, iron, manganese, potassium, tin, vanadium powder). Reaction with some metals requires moist CI2 or heat. Ignites with diethyl zinc (on contact), polyisobutylene (at 130°), metal acetylides, metal carbides, metal hydrides (e.g., potassium hydride, sodium hydride, copper hydride), metal phosphides (e.g., copper(II) phosphide), methane + oxygen, hydrazine, hydroxylamine, calcium nitride, nonmetals (e.g., boron, active carbon, silicon, phosphoms), nonmetal hydrides (e.g., arsine, phosphine, silane), steel (above 200° or as low as 50° when impurities are present), sulfides (e.g., arsenic disulfide, boron trisulfide, mercuric sulfide), trialkyl boranes. 

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