7782-79-8

Usage

Uses

Used in Automotive Industry:
Hydrazoic acid is used as a gas-forming agent in airbag systems for enhancing passenger safety during vehicle collisions. It rapidly generates a large volume of gas upon activation, inflating the airbag and providing a cushioning effect to protect the occupants.
Used in Aerospace Industry:
In the aerospace industry, hydrazoic acid serves as a gas-forming agent in escape chute systems, enabling quick and safe evacuation of passengers and crew members during emergencies.
Used in Heavy Metal Azide Preparation:
Hydrazoic acid is utilized in the industrial preparation of heavy metal azides, which are essential components in shell detonators. Hydrazoic acid forms readily when sodium azide reacts with acid or when hydrazine is mixed with nitrous acid, resulting in the production of heavy metal azides that are highly sensitive and effective as detonators.

Preparation

Hydrazoic acid is prepared by reacting sulfuric acid with sodium azide: H2SO4 + NaN3 → HN3 + Na2SO4 or by treating hydrazine with nitrous acid: N2H4 + HNO2 → HN3 + 2H2O or by heating sodium amide with nitrous oxide: NaNH2 + N2O → HN3 + NaOH

Production Methods

Hydrazoic acid is formed (1) by reaction of sodium nitrate with molten sodamide, (2) by reaction of nitrous oxide with molten sodamide, (3) by reaction of nitrous acid and hydrazinium ion (N2H5 + ), (4) by oxidation of hydrazinium salts, (5) by reaction of ethyl nitrite with NaOH solution and acidifying.

Reactions

Hydrazoic acid reacts (1) with metals, e.g., magnesium, aluminum, zinc, iron, to form azides or hydrazoates (or trinitrides), (2) with heavy metal salt solutions to form insoluble azides, e.g., silver azide AgN3, mercury(I) azide HgN3, lead azide PbN6. Silver, mercury(I), and copper(I) azides decompose in the light to form nitrogen plus the metal. (3) It reacts with NH4OH to form ammonium azide NH4·N3, (4) with hydrazine to form hydrazine azide N2H4·HN3, (5) with sodium hypochlorite plus acetic acid to form chlorazide ClN3, explosive, (6) with sodium amalgam to form NH3 with some hydrazine, (7) with potassium permanganate to form nitrogen and H2O.

Hazard

Dangerous explosion risk when shocked or heated. Strong irritant to eyes and mucous membranes.

Health Hazard

The acute toxicity of hydrazoic acidthrough inhalation and other routes of exposurehas been found to be high to very high.The symptoms and the intensity of poisoningare similar to sodium azide. It is, however,less toxic than hydrogen cyanide. Inhumans, inhalation of its vapors can produceirritation of eyes and respiratory tract, bronchitis,headache, dizziness, weakness, anddecreased blood pressure (Matheson 1983).Prolonged exposure to high concentrationscan result in collapse, convulsion, and death.An exposure to 1100 ppm for 1 hour waslethal to rats. Chronic exposure to a lowlevel of Hydrazoic acid in air may producehypotension.Animals given intraperitoneal dosages ofhydrazoic acid showed the symptoms ofheavy breathing, convulsions, depression,and fall in blood pressure. It affected thecentral nervous system, but no damage wasobserved in the liver or kidney.LD50 value, intraperitoneal (mice): 22 mg/kg.

Fire Hazard

In pure form or highly concentrated solution, hydrazoic acid is a dangerous explosive compound. It is unstable and sensitive to heat and shock. The explosion hazard decreases significantly with more dilute solutions. It forms shock-sensitive metal azides when react with metal salts, and fluorine azide with fluorine (Lawless and Smith 1968) and susceptible to form chlorine azide and bromine azide with chlorine gas and bromine vapor. All these products can explode violently on impact. With carbon disulfide it forms a violently explosive salt (Mellor 1946; NFPA 1997).

Waste Disposal

Hydrazoic acid may be destroyed by convertingit to sodium azide. The latter isdecomposed with nitrous acid in a hood(National Research Council 1995). The followingmethod is used. It is diluted in waterto a strength below 5%; or its solution inorganic solvents that is immiscible in wateris shaken vigorously with water in a separatoryfunnel. The aqueous solution containinghydrazoic acid is neutralized with sodiumhydroxide and separated from any organiclayer. Sodium azide, so formed, is destroyedby reacting the aqueous solution with anexcess of sodium nitrite followed by 20%sulfuric acid until the solution is acidic. Thereaction is carried out in a three-necked flaskequipped with a stirrer, a dropping funnel,and a gas outlet line to vent out nitric oxide.The reaction mixture is flushed down thedrain.

InChI:InChI=1/N3/c1-3-2/q-1/p+1

Upstream product

• 7732-18-5 water 
• 7697-37-2 nitric acid 
• 7664-39-3 hydrogen fluoride 
• 7705-08-0 iron(III) chloride 
• 12653-71-3 mercury(II) oxide 
• 302-01-2 hydrazine 
• 7440-66-6 zinc 
• 7440-09-7 potassium 
• 10024-97-2 dinitrogen monoxide 
• 7440-23-5 sodium 
• 7601-90-3 perchloric acid 
• 7632-00-0 sodium nitrite 
• 7722-64-7 potassium permanganate 
• 13863-88-2 silver(I) azide 

Downstream Products

• 12596-60-0 azide radical 
• 12190-75-9 nitrene chloride 
• 83438-07-7 azidochromium(III) meso-tetraphenylporphyrinate 
• 14215-30-6 copper(II) azide 
• 13776-62-0 trans-1,2-difluorodiazine 
• 12190-75-9 chloroamine 
• 13774-92-0 imino radical 
• 17778-88-0 NH₂ radical 
• 7727-37-9 nitrogen 
• 1418316-99-0 Ge(C₆H₃-2,6-(C₆H₂-2,4,6-(CH₃)₃)₂)₂(H)(N₃) 
• 14343-69-2 azide^(1-) 

Relevant academic research and scientific papers

New topology in azide-bridged cobalt(11) complexes: The weak ferromagnet [Co2(N3)4(HexamethylenetetramineKH 2O)]n

A new polynuclear azido-bridged Co(11) compound with formula [Co 2(N3)4(HMTA)(H2O)]n (1) (HMTA = hexamethyl-enetetramine) has been structurally and magnetically characterized. The compound 1 crystalli

The rates of the elementary reactions of NH(a1 Δ) with NH3(X) and HN3(X). The temperature dependences

The reactions NH(a) + HN3(X) → prod. (1) and NH(a) + NH3(X) → prod. (2) were studied in a quasi-static reaction cell in the temperature range 293 ≤ T/K ≤ 501 at a pressure of 10 mbar and 20 mbar, respectively, with He as the main carrier gas. The electronically excited reactant NH(a) was generated by laser-flash photolysis of HN 3, at λ = 308 nm and detected by laser-induced fluorescence (LIF). Also the ground state species NH(X) was detected by LIF. From the measured concentration-time profiles of NH(a) under pseudo-first order conditions, the rate coefficients k1(T) and k2(T) were obtained. For the rate coefficient k1 a positive temperature dependence was observed: k1(T) = (8.1 ± 0.5) × 10 13 exp[(-0.76 ± 0.05)/RT] cm3/mol s with a small activation energy of EA = 0.76 kJ/mol. For reaction (2) the rate coefficient k2(T) = (8.6 ± 0.6) × 1013 (T/298)-(0.6±0.1) cm3/mol s with a negative temperature dependence was measured indicating that the intermediate N 2H4, which decomposes to 2NH2, is formed without a barrier. The rate of the quenching channel NH(a) + NH3 → NH(X) + NH3 (2q) has the same temperature dependence as the rate of the overall reaction (2). The contribution k2q/k2 = 0.008 over the temperature range 293 ≤ T/K ≤ 501.

Mechanism of the Reaction of NH(1Δ) with NO in Argon Matrix

Matrix-isolated hydrazoic acid HN3 admixed with NO was photolyzed by a low-pressure mercury discharge lamp.Product analysis based on the FTIR spectroscopy has revealed the formations of NH, N2O, OH, HNO, and HONO as photoproducts.From the comparisons of the amount of HN3 consumed with that of N2O produced, we conclude that the reaction of NH(1Δ) with NO proceeds mainly through the process NH(1Δ)+NON2O+H.The quantum yield of N2O is found to be Φ1=0.7+/-0.1.The conclusion is in line with our previous results of the gas phase experiments at room temperature.

Collision-Induced Intersystem Crossing of NH(a1Δ, v''= 0.1) by N2 and Xe: Temperature Dependence (N2) and Product States (N2, Xe)

The elementary reactions of NM(a1Δ,v''=0) with N2 and Xe have been studied in the gas phase.NH(a,v'') was produced by laser photolysis of HN3 at λl = 248 nm and λL = 308 nm and detected directly by laser-induced fluorescence (LIF) via the c1Π-a1Δ) transition.Time resolution is based on the delay between the photolysis and the probe laser.The reaction rates were determined under pseudo-first-order conditions ( >>a,v'')>0), at different temperatures in the range 290 a,v''=0) + N2 -> products (1), k1 = (3.9 +/- 1.2) * 1011 exp(-(5.4 +/- 1.2) kJ mol-1/RT)cm3/(mol s); NH(a,v''=1) + N2 -> products (2), k2 = (8.6 +/- 2.7) * 1011 exp(-(4.4+/- 2.3) kJ mol-1/RT) cm3/(mol s); ND(a,v''=0) + N2 -> products (3), k3 = (4.7 +/- 1.7) * 1011 exp(-(5.2 +/- 1.1) kJ mol-1/RT) cm3/(mol s).The NH(X,v), which appeared as the product of physical quenching, was detected by LIF with the transition (A3Π-X3Σ-).In the reaction 1, 2, and 3 NH(X) and ND(X), respectively, were formed only in the vibrational ground state.The rate constant for the process NH(a,v''=1) + Xe -> products (5) was determined to be k5 = (7.7 +/- 0.9) * 1012 cm3/(mol s).In the physical quenching of NH(a,v'') (produced at λL = 248 nm) by Xe vibrationally vibrationally excited NH in the electronic ground sate NH(X,v=0,1,2) was detected NH(a,v''=0) (produced at λL = 308 nm) was quenched to NH(X,v=0).The different quenching dynamics of NH(a,v'') by N2 and Xe are discussed.

Phenylborylene: Direct spectroscopic characterization in inert gas matrices

The photolysis of bisazidophenylborane isolated in cryogenic matrices results in phenylborylene, a subvalent boron(I) species with a singlet ground state. Broad band irradiation of phenylborylene causes formation of benzoborirene by insertion into an ortho-CH bond. Copyright

Epitaxial growth of inn films by molecular-beam epitaxy using hydrazoic acid (HN3) as an efficient nitrogen source

Epitaxial InN films have been successfully grown on c-plane GaN template by gas-source molecular-beam epitaxy with hydrazoic acid (HN3) as an efficient nitrogen source. Results in residual-gas analyzer show that the HN3 is highly dissociated to produce nitrogen radicals and can be controlled in the amounts of active nitrogen species by tuning HN3 pressure. A flat and high-purity InN epifilm has been realized at the temperature near 550 °C, and a growth rate of 200 nm/hr is also achieved. Moreover, the epitaxial relationship of the InN(002) on the GaN(002) is reflected in the X-ray diffraction, and the full-width at half-maximum of the InN(002) peak as narrow as 0.05° is related to a high-quality crystallinity. An infrared photoluminescence (PL) emission peak at 0.705 eV and the integrated intensity increasing linearly with excitation power suggest that the observed PL can be attributed to a free-to-bound recombination.

3D azido-bridged cobalt(II) complexes with diazines as coligands

Two new three-dimensional azido-bridged Co(II) compounds with formula [Co(N3)2(2,5-Me2pyz)]n (1) and [Co(N3)2(2-ampym)]n (2) have been structurally and magnetically characterized

A new energy transfer chemical laser at 1.315 μm

CW laser action has been demonstrated on the electronic I*(2P1/2)→I(2P 3/2) transition of atomic iodine at 1.315 μm from the NCl (a1Δ)+I(2P 3/2) energy transfer reaction. The stimulated emission was generated in a transverse subsonic flow device when hydrogen azide, HN3, was injected into a flow of iodine and chlorine atoms. The measured laser output power was 180 mW.

Temperature dependence of the UPS and HREELS of HN3 and DN3 on Si(110)

HN3 was used for the first time as a nitrogen source for nitridation of Si surfaces. Its interaction with Si(110) was studied with HREELS and UPS at temperatures between 120 and 1350 K. HN3 was found to adsorb molecularly on the Si surface at 120 K, as all molecular vibrational peaks, such as HN-NN stretching at 150 meV, HNN=N stretching at 265 meV and H-NNN stretching at 414 meV, were clearly observed in HREEL spectra. A similar HREELS study of DN3 was carried out to confirm some of the EELS assignments. Upon warming up to 220 K, HN3 started to dissociate into N2 and NH, which further dissociated to give N and H as the surface was annealed from 580 to 800 K, H adatoms were observed to desorb at T > 800 K, while N remained on the surface, forming Si3N4 at T ? 1350 K.

Binary Zinc Azides

Pure, solvent-free Zn(N3)2 was prepared by reaction of diethyl zinc and hydrazoic acid in aprotic solvents. The single-crystal structure determination, along with the comprehensive characterization of α-Zn(N3)2 and two metastable polymorphs, could be achieved for the first time. Since these data disagree in large parts with the known, previously reported values, all previous syntheses of Zn(N3)2, and for comparison Zn(N3)2×2.5 H2O and Zn(OH)N3 were reinvestigated, indicating that some of the earlier work has to be revised.