Thallium -azide

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]. 

Kabanov, A. A. etal., Russ. Chem. Rev., 1975, 44, 538-551 Application of electric fields to various explosive heavy metal derivatives (silver oxalate, barium, copper, lead, silver or thallium azides, or silver acetylide) accelerates the rate of thermal decomposition. Possible mechanisms are discussed. 

Thallium Azide (Formerly called Thallous Trinitride or Thallium Azoimide), T1N3, mw 246.41, N17.05%, pal yel tetrag crysts which form as wh ppt mp 330-40° (Refs 1 6), explodes 430° (Ref 6) Qexpln 232 cal/g or... 

TIN3 (c). Wohler and Martin1 found the heat of decomposition of thallium azide to be 54.7. 

Thallium Azide (Formerly called Thallous Trinitride or Thallium Azoiroide), TIN, mw... 

Figure 22. Relation between the spark energy necessary for initiation and the ambient temperature for thallium azide, 1, and silver azide, 2 [97 J.

It has long been assumed that since lead azide, for example, is more sensitive than sodium azide when impacted, the reactivity of the former is greater than that of the latter. That this is not so was demonstrated by Walker [58] and Fox [59], who compared the rates of slow thermal decomposition under identical experimental conditions for the azides of sodium, thallium, and lead. The results, summarized in Figure 7, show that over most of the temperature range studied lead azide is the least reactive, and that above about 560°K sodium azide reacts more rapidly than either lead or thallium azides. Moreover, above 590 K the rate of evolution of heat is greater in sodium than in lead azide. Alternatively, the application of data for the energetics of decomposition derived from slow reactions is not applicable to fast reactions, since in the latter thermodynamic equilibrium is not attained and the mechanism for slow decomposition discussed in Chapter 6 may not apply. There is some evidence that this is so [60]. 

The results indicate that, on the basis of the ductile-brittle temperatures, lead azide should be most susceptible to the fracture method of initiation. The ductile-brittle temperatures of sodium azide and thallium azide are the same, implying similar shock sensitivities this is contrary to experience. (See, however, the discussion in Sections C.2.a and C.3.a of Chapter 5 relating to stability, in the energetic sense, against conversion to the end products colloidal metal and nitrogen gas. These bear on the magnitude of the exothermicity parameter Q appearing in the heat-transfer equation and can qualitatively explain the discrepancy. Sensitivity and stability are concepts not independently defined or operable). 

Thallium is found in significant amounts. One unit at the Experiment Station developed explosives and fuses. Thallium azide, thallium nitride, and thallium fulminate are shock sensitive explosives and emit poisonous fumes. It would have been an ideal subject of experimentation. Thallium as high as 58.52 ppm was found. The oral LDjg for rats is 16 mg/kg, and the LDjo for children is 8 mg/kg. LDjg is the lethal dose at which 50 percent of the population dies. 

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