Ralf Haiges - Metal Fluorides as Precursors for Environmental Friendly Energetic Materials: Replacements for Lead Diazide.

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      Publication Details (including relevant citation   information): Haiges, Ralf, Christe, Karl O., Boatz,   Jerry A., Dixon, David A., 20th Winter Fluorine Conference,   American Chemical Society, Division of Fluorine Chemistry, St.   Pete Beach, FL, United States, January 9-14,   2011, pp FLUO-30

      Abstract: Metal fluorides are excellent starting   materials for the synthesis of polyazido compds. The reaction of   a fluoride with an excess of trimethylsilyl azide in a suitable   solvent results in complete fluoride-azide exchange and the   formation of the corresponding azido compd. The most widely used   compd. as primer and initiation charge for propellants and   secondary explosives is lead diazide. There is a high interest in   new environmentally benign and non-toxic energetic materials   because of the environmental hazards and human toxicity issues   assocd. with the prodn., use, and disposal of lead diazide. The   fluoride-azide exchange reaction was utilized to synthesize new   polyazido compds., which could serve as drop in replacement for   lead diazide. The reaction of easily accessible BiF3 with   trimethylsilyl azide results in the formation of Bi(N3)3. This   neutral triazide was converted into the novel polyazido anions   [Bi(N3)4]-, [Bi(N3)5]2- and [Bi(N3)6]3-. While the crystal   structure of [PPh4][Bi(N3)4] contains polymeric anion chains made   of [Bi(N3)4]- units linked by two end-on azide-bridges, those of   [PNP]2[Bi(N3)5] and [PPh4]3[Bi(N3)6] contain well sepd.   [Bi(N3)5]2- and [Bi(N3)6]3- units, resp. Furthermore, the novel   vanadium azides V(N3)4 and [V(N3)6]2- have been prepd. by   fluoride-azide exchange. While the reaction of VF5 with Me3SiN3   proceeded in redn. of the metal to vanadium(IV), the first   vanadium(V) azide was prepd. from [VF6]-. The predicted   structures of free [V(N3)6]2- and [V(N3)6]- show significant   differences. While the VN6 skeleton of [V(N3)6]2- exhibits almost   perfect S6 symmetry, that of [V(N3)6]- is significantly distorted   from octahedral symmetry. [on SciFinder(R)]

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