Decomposition hydrazoic acid

The decomposition of hydrazoic acid in a low pressure electrical discharge seems to give a similar intermediate.88... 

The slow, thermal decomposition of hydrazoic acid in a static system has been studied by Meyer and Schumacher58. It turned out to be completely governed by heterogeneous catalysis. There are no studies on the kinetics of the homogeneous decomposition of this substance save for the investigation of its decomposition flame59. From the variation of flame properties with pressure it can be deduced that second-order reactions control the over-all rate. The unimolecular reaction... 

Sodium azide is a toxic as well as an explosive substance (Patnaik, P. 1999. A Comprehensive Guide to the Hazardous Properties of Chemical Substances, 2nd e(j New York John Wdey Sons). Although inert to shock, violent decomposition can occur when heated at 275°C. Contact of solid or solution with lead and copper must be avoided. Reactions with halogens, carbon disulfide, or chromyl chloride can be explosive. Dissolution in water produces toxic vapors of hydrazoic acid. The salt is an acute poison causing headache, hypotension, hypothermia, and convulsion. 

Hydrazinofluorophosphines, 13 393 Hydrazoic acid, 9 134 reaction mechanisms, 22 131-135 of coordinated azide ion, 22 133-135 oxidation by metals, 22 131, 132 by nonmetals, 22 132, 133 thermal decomposition of, 14 121 Hydrides... 

Lead azide [Pb(N3)2] (LA) is a salt of hydrazoic acid (N3H, highly poisonous) and is prepared by reacting solutions of sodium azide and lead acetate or nitrate. This exists in two forms the a form (orthorhombic and stable) and P form (monoclinic) which has a tendency to revert back to the a form. The P form is much more sensitive. The two forms differ in their rate of decomposition when heated. Crystalline LA is stored in dry conditions because it becomes more sensitive when... 

Gaseous hydrazoic acid is liable to non-explosive decomposition at a temperature above 250°C. At 33°C the half-life is 12 min. 

Hydrazoic acid is decomposed by ultra-violet radiation. In all probability the decomposition proceeds gradually with the formation of free radicals (Beckman and Dickinson [48]) ... 

A number of investigations have been devoted to the thermal decomposition of hydrazoic acid or to decomposition produced by electric discharge. Thus Rice and Freamo [50] established that its thermal decomposition at 77°K leads to the formation of a blue-coloured sediment. At a higher temperature, 148°K, it changes colour, forming a white substance which has been identified as ammonium azide. They suggested that the blue colour is caused by the presence of the free imino radical NH. 

Using Norrish s flash photolysis method [54], Thrush [55] examined the decomposition of hydrogen azide in the presence of an excess of inert gas. The absorption spectra characteristic of the radicals NH and NH2 were observed. He therefore suggested an alternative scheme for the decomposition of hydrazoic acid, different from that proposed by Beckmann and Dickinson [56] ... 

Becker, Pimentel and Van Thiel s [58] equally interesting study of the photolysis of solid hydrazoic acid led to the assumption that the radicals NH, NH2 and N3 are formed during decomposition. 

The formation of hydrazoic acid and its derivatives together with ammonia from diazo compounds under the influence of hydrazine or its derivatives was explained by Thiele [68]. At an intermediate stage a diazohydrazine, e.g. C6H5N2NHNH2, is formed which then undergoes decomposition according to two parallel reactions ... 

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. 

The decomposition of other salts of hydrazoic acid takes a similar course. 

In the first stage of the reaction an alkoxyl anion and the nitrohydrazine cation are formed which afterwards react together to give the corresponding alcohol and nitrohydrazine. Nitrohydrazine reacts with excess hydrazine to produce tetrazene, nitrous acid and di-imid. Then the tetrazene decomposes to form ammonia and nitrogen from di-imid on the other hand tetrazene, hydrazine and nitrogen are formed. Hydrazoic acid and ammonia are then formed as decomposition products of tetrazene. 

This substance forms salts with acids, and was first isolated in the form of its nitrate. The nitrate is not detonated by shock but undergoes a rapid decomposition with the production of light when it is heated. The picrate and the perchlorate explode violently from heat and from shock. Guanyl azide is not decomposed by boiling water. On hydrolysis with strong alkali, it yields the alkali metal salt of hydrazoic acid. It is hydrolyzed by am-moniacal silver nitrate in the cold with the formation of silver azide which remains in solution and of silver cyanamide which appears as a yellow precipitate. By treatment with acids or weak bases it is converted into 5-aminotetrazole. 

This reaction works well for simple alkenes and cycloalkenes. Attempts to add hydrazoic acid to di-arylalkenes in the presence of sulfuric acid, however, leads to considerable decomposition due to Schmidt rearrangement.260... 

The decomposition of a compound containing a chain of three or more nitrogen atoms.—For example, M. Freund and A. Schander prepared hydrazoic acid by the action of alkalies on amidothionitrazole ... 

Quantum-chemical calculation of the decomposition of methylpentazole has shown that methylpentazole is as stable as aromatic pentazole derivatives <2003CEJ5511>. In the reaction of 1SN-Iabeled diazomethane with hydrazoic acid at — 80 °C, which leads to methyl azide, no methylpentazole intermediate has been detected <1932G716, 1958HCA1823>. Therefore, methylpentazole can only be synthesized by using a different route. Other substituents like CN, F, or NH2 lead to pentazoles with lower activation barriers (Table 5) than the known arylpentazoles. 

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