1 Lead Azide Carbonate

There have been many other reports of single-source azido precursors, all aimed at achieving device-quality films using moderate deposition conditions. The azide precursors have the advantages of (i) having preformed Ga—N bonds and (ii) only a limited number of the undesirable Ga—C and N—C bonds which can lead to carbon incorporation into the nitride films.311 A list of azido-based precursors and deposition conditions is given in Table 14. 

By further nitration with more concentrated acid o- and p-nitro-phenols are converted into the same 2 4-dinitrophenol, and finally into picric acid. Polynitro-derivatives of benzene, such as picric acid and trinitrotoluene, can be caused to explode by detonation with mercury fulminate or lead azide. (The formulae of these two compounds should be written.) They are endothermic, i.e. the oxygen of the nitro-group can oxidise carbon and hydrogen within the molecule and heat is liberated. This intramolecular combustion is rather considerable in the case of picric acid, which is decomposed in accordance with the equation ... 

The need for great care to avoid the possibility of detonation of perchloryl compounds by exposure to shock, overheating or sparks is stressed. The compounds are generally more sensitive to impact than mercury fulminate and are of comparable sensitivity to lead azide [1], A range of highly explosive alkyl perchlorates [2] and perchlorylamines [3] have been prepared by interaction of dichlorine heptaoxide with alcohols or amines in carbon tetrachloride solution. The solutions of the products were not sensitive to mechanical shock and could... 

Lead azide explodes on heating at 350°C or on percussion. Its detonation velocity is 5.1 km/sec (Meyer, E. 1989. Chemistry of Hazardous Materials, 2nreaction with carbon disulfide and forms shock-sensitive copper and zinc azides when mixed with the solutions of copper and zinc salts (Patnaik, P. 1999. A Comprehensive Guide to the Hazardous Properties of Chemical Substances, ed. New York John Wdey). 

Service lead azide (SLA) SLA is prepared by double decomposition of lead acetate and sodium azide in the presence of sodium carbonate and acetic acid. 

Lead azide, like hydrazoic acid, is liable to undergo oxidation and reduction reactions. It is partially decomposed by atmospheric oxygen to form free hydrazoic acid, nitrogen and ammonia. This reaction is promoted by the presence of carbon dioxide in the air. When boiled in water, lead azide undergoes slow decomposition with the evolution of hydrazoic acid. 

HaS or HI, so as to form lead carbonate, sulfide or iodide oidy on the surface without penetration into the crystal (Ref 22). This treatment will unquestionably reduce the efficiency of LA because it will be contaminated by inert materials l)Solubiliry of LA in water or in 50% alcohol was detd as described in item VII F tinder Lead Azide Plant Analytical Procedures In addn to above listed tests, the various LA s were loaded in M47 caps as intermediate chges together with NOLNo 130 as a primary chge and RDX as a base chge and subjected to the following tests given in the Purchase Description PA-PD-202, with Rev 1 dated 30 Sept 1952 and Amend 1 dated 27 Jan 1953 ... 

Uses of Sodium Azide. The principal use of NaN, in the expl ind is in the prepn of alkali alkaline earth and other azides (Refs 37,38, 42,96,113,201,% others) (See Lead Azide, Plant Manufacture, etc). Meissner (Ref 44) used equiv quants of NaN, and a heavy metal salt, such as Pb acetate, for the continuous prepn of LA. Matter (Ref 33) found that NaN, was freed from carbonates by the addn of aq... 

Many other ignition compns have been patented such as bis-triethyl lead styphnate, triethyl lead -basic lead styphnate, triethyl lead azide, mono -triethyl lead azo-aminotetrazole, bis-triethyl lead azoaminotetrazole, triethyl lead azidodithio-carbonate, diethyl lead diazide bis-basic diethyl lead styphnate, etc. The ignition compns mentioned above have an "overall lag of less than 0.0009 secs when fired at 12 amps, but in some cases this lag is even smaller, viz, 0.0002, 0.0003, 0.0004, 0.0005 or 0.0006secs... 

DNAN forms colorless crystals with a melting point of 120 Celsius. It is fairly soluble in hot water, hot ethanol, methanol, and acetone. It is less soluble in cold water, cold ethanol, and insoluble in chloroform, benzene, ether, and petroleum ether. DNAN is somewhat hygroscopic, and moisture slowly decomposes it—should be stored in a desiccator. A small sample bums leaving a residue of carbon when ignited—a small sample can be detonated by the blow of a hammer. DNAN can be used in explosive compositions when alloyed with TNT, or other low melting secondary explosives, gun propellants with nitrocellulose, nitro starch, or nitroglycerine, and rocket propellants when mixed with ammonium perchlorate. DNAN also demonstrates usefulness for priming mixtures with lead azide, lead styphnate, or diazodinitrophenol, and for use in fireworks. ... 

Some substances, including impurities, enhance the decomposition of azides. The impurities can be present in the course of preparation of azides or formed during their storage. It is known that the presence of carbon dioxide in air may produce a decomposition of lead azide. Also water vapour in air even at rcoin temperature may accelerate (he decompr>sition. fhis problent was tackled by. Reitzner (115]. He found that the induction period was the result of the re-laction of water vapour with lead. 

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