Bismuth Azide

The bismuth-azide bond has received some attention. The synthesis is often surprisingly facile (equation 57).195 The organobismuthine azides are more unstable, but the azide group displaces an alkyl group from trialkylbismuthine (equation 58).196... 

Pure silver azide explodes at 340°C, but presence of below 10% of copper(I) or (II) oxides or sulfides, copper(I) selenide or bismuth(III) sulfide reduces the detonation temperature to 235°C. Concentrations of 10% of copper(II) oxide, copper(I) selenide or sulfide further reduced it to 200, 190 and 170°C, respectively. 

Bismuth Triazide, Bi(Ns)j, mw 335.07, N 37.63%. The prepn of this compd was attempted by Vournazos (Ref 1) who treated Bi iodide with an equimolar part of Na azide. The following reaction occurred 2 Bi I, + 2 NaNj + Ha0 - BiOI + Bil + 2HNa + 2NaI and with twice this amt of Na azide Bila + 2NaNs + HaO - BiOI + 2Nal + 2HN,. It was thought by Vournazos that an unstable bismuth iodo-diazide, Bi I(Ns)a, was formed but immediately hydrolyzed (Ref 2)... 

Quaternary bismuth compounds are generally unstable. When the anionic ligand is chloride or bromide, the compounds decompose spontaneously on standing azides and selenocyanates decompose more rapidly. The perchlorates, tetrafluoroborates, and hexafluorophophates, however, are considerably more stable but eventually decompose. The vibrational spectra of the latter compounds show the presence of the free ion and are consistent with a tetrahedral BiC4 skeleton for the cation. The acetonyltriphenyl compounds, [(C(5H5)3BiCH2COCH3]Y, where Y is C10- 4 or BF- 4, also appear to be true bismuthonium salts. 

Sodium thiatriazole-5-thiolate gives colored precipitates with copper(II) or bismuth salts. This reaction may be used as a test for soluble inorganic azides by way of their reaction with CS2, which yields thiatriazole-5 -thiolates.47... 

Bismuth Triazide, Bi(N,), mw 335.07, N 37.63%. The prepn of this compd was attempted by Vournazos (Ref 1) who treated Bi iodide with an equimolar part of Na azide. The following reaction occurred 2 Bi I, + 2NaN,... 

H20 BiOI + Bil, + 2HN, + 2NaI and with twice this amt of Na azide Bils + 2NaNs + HaO BiOI + 2NaI + 2HNS. It was thought by Vournazos that an unstable bismuth iodo-diazide, Bi I(NS)2, was formed but immediately hydrolyzed (Ref 2)... 

The phosphoms azides P(N3)3, P(N3)4+, P(N3)5, and P(N3)6 have long been known (see Phosphorus-Nitrogen Compounds). More recently, the binary arsenic, antimony, and bismuth M(N3)3, the cations As(N3)4+ and Sb(N3)4+, and the arsenic and antimony M(N3)4 and M(N3)e anions have been synthesized. While the cations and binary azides are very sensitive(the bismuth compound has not been isolated), the anions, in combination with sufficiently large cations such as As(Ph)4+, are less sensitive. Attempts to prepare the As(V) and Sb(V) pentaazides resulted in explosions. 

Triorganoantimony and -bismuth react with chloramine-T or with sulfonyl azides to give the corresponding imines (equations 250 - and 251 ). 

Singh [16] showed that bismuth incorporated in the lead azide lattice sensitized the explosive to thermal initiation Figure 2 shows the explosion-temperature curves obtained. 

---