Mercurous azide

Hydrazoic acid Hydrides, volatile Hydrogen cyanide (unstabilized) Hydrogen (low pressure) Hydrogen peroxide (> 35% water) Magnesium peroxide Mercurous azide Methyl acetylene Methyl lactate Nickel hypophosphite Nitriles > ethyl Nitrogen bromide... 

Methyl mercuric Azide (Mercuric methylazide). CH3HgN3 cry sts from alc mp 130.5° decompn explosively ca 200°. Was prepd by Perret Perrot (Ref 3) by treating methyl mercuric hydroxide, CH3HgOH (Ref 1) with hydrazoic acid... 

It becomes a problem in semantics to set a time limit for "development within which a process can be considered "spontaneous or "instantaneous . These two words seem to apply well to such extremely sensitive compounds as Nitrogen Triodide and Cupric Azide, which explode at the slightest touch when dry and, in addition, explode at a fairly low temperature. Attempts to correlate initiation in such cases with the attainment of a certain temperature seem unrealistic, especially in view of differences between relative sensitivity of different compounds to mechanical and thermal influences. For example, Mercuric Azide is so sensitive to impact that it explodes even under water, hut its heat sensitiveness is about the same as that for Cadmium Azide, which has been reported not to explode by percussion (Ref 5) Information about susceptibility of different explosives to spontaneous detonation is highly important from the viewpoint of safety. In Refs which follow are listed examples of spontaneous detonations of substances, some of them previously considered safe in this respect... 

Mercurous Azide was prepd by T. Curtius (Vol 1 of Encycl, p A591)... 

Hydrazine, Anhydrous was prepd in 1894 by Lobry de Bruyn, but its salts were prepd in 1875 by Emil Fischer, who coined the name hydrazin . Its derivs were investigated during WWII by Col L.F. Audrieth. More information is given in this Volume under Hydrazine and Derivatives 1894. Mercuric Azide was prepd by M. Berthe-lot P. Vieille (Vol 1 of Encycl, p A590)... 

Mercuric Fulminate MF + 10% KClOg MF + 20% KCIO3 Silver Fulminate Lead Azide Silver Azide Mercurous Azide Lead Styphnate Silver Acetylide Lead Picrate... 

Ag Fulminate 5) Lead Azide 6) Cuprous Azide 7) Cuprous Fulminate 8) Mercurous Azide 9) Mercuric Fulminate 10) Tellurium Azide 11) Tellurium Fulminate... 

According to Kaufman [91] spontaneous explosion can also take place during the growth of a-lead azide crystals, e.g. when a supersaturated solution of lead azide in ammonium acetate is seeded with crystals of the a-form. Spontaneous explosions have also been observed with mercuric azide and in some cases with cadmium azide. 

Mercuric azide, Hg(N3)2, occurs in two allotropic modifications a (orthorhombic) and P (monoclinic), like lead azide (Miles [75] Garner and Gomm [37]). The latter is obtained like /Mead azide, by slow diffusion of the solutions. During crystallization spontaneous explosion may occur. Mercuric azide also explodes during crystallization from a hot, aqueous solution. 

The physical properties of mercurous azide — Hg2(N3)2 — were examined by Evans and Yoffe [33] and its photochemical decomposition by Deb and Yoffe [26], The activation energy was found to be 8.4 kcal/mole. 

Ammono-basic Mercuriazid. See under Mercuric Azide... 

Initiating Efficiency. More efficient initiator than MF and slightly less efficient than di-azodinitrophenol(See Table under Mercurous Azide and Refs 16,29,38,46,48,49,59.71,73, 79,81,94,101 116)... 

According to Stettbacher, mercuric azide develops the same vol of gas on deton as MF but it is 20 times more brisant. Wohler Krupko (Ref 3) observed that its sensitivity depended on the cryst size of the azide. Mercuric azide is considered to be more sensitive to impact and friction than MF and is so unstable that it frequently undergoes spontaneous deton at the slightest touch even under w (Refs 5 7). Hitch (Ref 4) noted this sensitivity expecially when the azide was prepd from mercuric nitrate and Na or K azide solns but by careful thermal studies he decompd it quanty into its elements without expln below 300°. Miles (Ref 8) reported that in every case when /3-crysts of Hg(N3)2 were present the material was likely to expl, and in w or more rapidly in mercuric nitrate soln, the /3-type was unstable being transformed to the o-type, as in the parallel case of LA,... 

Ref 6). According to Sax (Ref 22), mercurous azide is highly toxic. When heated it emits fumes of Jig and may expl on exposure to light or heat... 

Initiating Efficiency, see table under Mercurous Azide (or Ref 16)... 

The white powder is soluble in hot water but very sparingly soluble in cold water. On cooling the hot soln., the salt separates in long, white, acicular crystals. The salt is said to be very explosive. A. R. Hitch said that when mercuric azide was heated, gas came off at 212°, and the salt began to boil at 215° and it exploded... 

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