Cupric azide

Lead azide tends to hydrolyze at high humidities or in the presence of materials evolving moisture. The hydrazoic acid formed reacts with copper and its alloys to produce the sensitive cupric azide [14215-30-6] Cu(N2)2- Appropriate protection must be provided by hermetic sealing and the use of noncopper or coated-copper metal. 

Methylamine Hydrobromide Cupric Azide Complex, (MeNHa+)Cu(N3)2-Br-, CHgBrCuN , mw 259.61, N 37.77%. Dark violet crysts, mp 116°. It detonates with a hammer blow... 

Methyl Ammonium Chloride Complex with Cupric Azide, MeNH3Cl.Cu(N3)2, CH6C1CuN7, mw 215.15, N 45.58% dark violet crysts, mp 150° with decompn... 

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... 

Hexazidocuprate-Lithium Salt. L [Cu(N3)6] mw 343.49, N 73.42% crysts with 3H20 which is lost above 120°. The anhydrous compound explodes at 224-5°. Prepd by dissolving Cupric Azide in aq or ale soln of Lithium Azide Refs 1) Gmelin, Syst No 60, Teil B, 150 (1958)... 

Black Powder 225 to 300, NC (13%N) 185, smokeless powder 185, NG 160, Nitrostarch 170, NH4N03 225, Tetryl 190, Mercury Azide 200, Silver Azide 200, Lead Azide 340 to 350, Cuprous Azide 210 to 350, Cupric Azide 245, Mercuric Fulminate 160 to 200, Silver Fulminate 200, Chedaite 200, blasting gelatin 207 to 211 and Picric Acid 225 to 350°... 

Silver Azide, Cadmium Azide, Cupric Azide, Triazidotrinitrobenzene, Chloratotrimercuraldehyde, Nitrogen Suifide Hexamethylenetriperoxidediamine Until WWI, Mercuric Fulminate was the principle initiating agent used, but Lead Azide has now replaced it. Lead azide is not the most powerful azide, but is more stable and less dangerous to handle than some of the other ones. Cadmium Azide, for example, is more powerful than Lead Azide but is unsuitable as an initiating agent because it is difficult to prepare and is soluble in water... 

Figure A.49 Cupric azide primary high explosive.

Long experience in the storage of blasting caps filled with lead azide has shown that this substance reacts with copper or brass to form cupric azide, which is highly sensitive to friction and impact. For this reason lead azide is compressed only into aluminium and zinc cases. 

Cupric azide, Cu(N3)2, is of great practical significance since it can be formed in addition to cuprous azide by long term action of lead azide on copper or its alloys. 

Curtius and Rissom [41] prepared cupric azide by the action of an aqueous solution of sodium azide on an aqueous solution of cupric sulphate, obtaining the salt in a hydrated form. The anhydrous salt was prepared by Straumanis and Ciru-lis [125] in the form of dark brown, reddish sediment by reaction of lithium azide on cupric nitrate in an alcohol solution. Another method described by Curtius consists of reacting hydrazoic acid with metallic copper in an aqueous medium. 

Green cupric azide has also been described (Dennis and Isham [44]). It is formed by the action of hydrazoic acid on cupric hydroxide or (according to Straumanis and Cirulis) on cupric oxide. It is sometimes grey in colour. 

Cupric azide is insoluble in water, but is soluble in dilute acids and in acetic acid. It is decomposed by concentrated sulphuric acid, evolving nitrogen. It dissolves in an aqueous solution of ammonia and aliphatic amines to form a complex compound. 

Boiling in water (Wohler and Krupko [80]) leads to hydrolysis with the formation of basic cupric azide. Long-continued boiling causes complete hydrolysis to cupric oxide and free acid. Black cupric azide, Cu(N3)2, when exposed to the action of air for 2 months, is completely converted into a yellow basic salt. This is discussed later. 

The ignition temperature of cupric azide is 202-205°C. The dry substance is exceptionally sensitive to friction, especially the green modification, and is often exploded by contact. It is also very sensitive to impact the green modification is exploded by a 2 kg weight falling from a height of less than 1 cm, the black one from a drop of about 1 cm. 

Basic cupric azide, Cu(OH)N3, prepared by Wohler and Krupko, is yellow coloured. According to Straumanis and Cirulis it is less sensitive to friction and impact. It is exploded by a 1 kg weight falling from a height of 7-8 cm. Its ignition temperature is the same as that of the neutral salt (203-205°C). 

Complex salts of cupric azide are also explosive. The salt Cu(NH3)4(N3)2 is much less sensitive to impact than cupric azide itself. The complex lithium-cupric salt Li4[Cu(N3)6] has exceptionally strong initiating properties. 

The explosive properties of sodium, calcium, strontium and barium azides have been investigated at the Chemisch-Technische Reichsanstalt [135]. These azides differ markedly from lead, silver and cupric azides in that they show none of the properties of primary explosives. All three may be ignited by a spark, a glowing wire or the flame of blackpowder. Calcium azide bums most rapidly and has distinctly marked explosive properties. Larger quantities of it may explode when ignited in a closed tin, while strontium and barium merely bum violently. Calcium azide detonates under the influence of a detonating cap. The sodium azide does not decompose in these conditions. The other azides show weak decomposition under the influence of a standard (No. 3) detonator. Their most important properties are tabulated below. 

Aminoefnanui-bii[cu)ipcf(i]/ diulidt], Ethan d-amine di (cupric azide) or Monoethanol ami no-tetrazido-copper. [(N.) Cu — H. N CH.-CHa OH-Cu(Ns)2], dk grn crysrs explg ca 186° or when thrown on a preheated metal block. It was obtained in a impure state and in small yield from Cu diazide and amino-... 

Cupric Azide (formerly called Cupric Azoimide or Copper Trinitride) CufNj, mw 147.59,... 

The use of polyvinyl ale or gelatin for the desensitization of cupric azide, its decompn in moist air or high temp and its use in detonators were described recently (Ref 20a)... 

Ref 11). Other reactions involving cupric azide are described below ... 

Cupric Amminoazide (Ammoniate of Copper Azide), Diammine copper azide, [Cu(NHj)a] (Nj)a, mw 181.65, N 61.69% green crysrs, expl when heated or struck. Obtained by Dennis Isham (Ref 2) by shaking freshly pptd black cupric hydroxide, while still moist, with ao excess of hydrazoic acid, and washing and dissolving the ppt in aq ammonia. This compd was also prepd by Browne et al (Ref 6) and studied by Strecker Schwinn (Ref 8) and by Straumanis Cirulis (Ref 11) (See also Ref 21, p 149 and Table D under Ammines in this dictionary). Tetrammine copper azide, [Cu(NHs),](N3)a, mw 215.72, N 64.90%, blue crysts, expl at 202° and on impact. Prepd by Strecker Schwinn (Ref 8) and by Straumanis Cirulis (Ref 11) from cupric azide and NHS, (either liq or the dry gas). Only the di- and tetrammino- compds were prepd, (See also Ref 21, p 149 and Table D under Ammines)... 

Cupric Azide, Basic (Anhydrous Cupric Oxyazide), CuO-Cu(Ns)a, mw 227.13, N 37.00% yel solid, expl 203-5° (Ref 11), ignites 245° (Ref 3). Cirulis Straumanis (Ref 11) assigned to it the formula Cu(0H)Ns. Basic cupric azide was first prepd by Wohler ... 

Krupko (Ref 3) on heating cupric azide in w at 70-80°, followed by drying in air free from C0lt until hydrazoic acid is evolved. This compd expl at 7 to 8 cm under 1 kg impact... 

Cupric Azide Complexes. Cupric azide forms numerous complex compds, such as [Cu (C8H,N)a](N,)a and [Cu(CaHl(NHa)J)a](Ns)a, wherein the azide group is analogous to the corresponding halides (Ref 8). The cupric pyridine azide, Cu(Ns)a 2Cs Hg N, mw 305.78,... 

N 36.65% brn ndls insol in water but readily sol in dil acids. Was first prepd by Dennis Isham (Ref 2) by the action of pyridine on cupric azide. It was studied by Srrecker Schwinn (Ref 8) and by Cirulis Straumanis (Ref 11, p 341). This compd expl at 205° and under a 1 kg impact at 20 cm. It is an expl weaker than Cu(N3)a 2NH3 (Refs 7 21)... 

According to Stewart (Ref 11) moist LA is not affected by contact with steel or Fe whereas MF changes under storage in contact with these metals. Also Cu, brass and A1 had considerably less effect on LA than on MF (Ref 28). LA does corrode Cu with the formation of the extremely sensitive Cupric Azide (qv) (Ref 99). Eschback LUbbecke (Ref 39) avoided the reaction of LA with Cu or brass parts by coating them with Cd. 

Since LA reacts with Cu or brass detonator capsules to form extremely dangerous Cupric Azide(qv), this difficulty has been overcome by the use of Al, A1 alloy, iron or paper containers for example Al detonator shells were patented by Eschbach (Ref 15), Biazzi (Ref 49), Lewis (Ref 53), duPont (Ref 58), Noddin (Ref 59), Rubenstein Imperial Chem Inds... 

BASF see Badische aniline-und sodafabrik 2 B4 Bashforth chronograph see Chronographs 3 C308 Basic cupric azide 1 A533 Basic lead acetate 1 A28 Basic lead azide 1 A555... 

Cupric azide 1 A532-A533 expl properties 1 A532-A533 preparation and properties 1 A532... 

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