Silver azide

Last updated
Silver azide
Silver-azide-high-T-single-layer-3D-vdW.png
Names
IUPAC name
Silver(I) azide
Other names
Argentous azide
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.034.173 OOjs UI icon edit-ltr-progressive.svg
PubChem CID
UNII
  • InChI=1S/Ag.N3/c;1-3-2/q+1;-1 Yes check.svgY
    Key: QBFXQJXHEPIJKW-UHFFFAOYSA-N Yes check.svgY
  • InChI=1/Ag.N3/c;1-3-2/q+1;-1
    Key: QBFXQJXHEPIJKW-UHFFFAOYAJ
  • InChI=1S/Ag.N3/c;1-3-2/q+1;-1
    Key: QBFXQJXHEPIJKW-UHFFFAOYSA-N
  • [Ag+].[N-]=[N+]=[N-]
Properties
AgN3
Molar mass 149.888 g/mol
Appearancecolorless crystals
Density 4.42 g/cm3
Melting point 250 °C (482 °F; 523 K) explosive
Boiling point decomposes
Solubility in other solvents2.0×10−8 g/L
Structure
Orthorhombic oI16 [1]
Ibam, No 72
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
Very toxic, explosive
NFPA 704 (fire diamond)
NFPA 704.svgHealth 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasFlammability 0: Will not burn. E.g. waterInstability 4: Readily capable of detonation or explosive decomposition at normal temperatures and pressures. E.g. nitroglycerinSpecial hazards (white): no code
3
0
4
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Silver azide is the chemical compound with the formula AgN3. It is a silver(I) salt of hydrazoic acid. It forms a colorless crystals. Like most azides, it is a primary explosive.

Contents

Structure and chemistry

Silver azide can be prepared by treating an aqueous solution of silver nitrate with sodium azide. [2] The silver azide precipitates as a white solid, leaving sodium nitrate in solution.

AgNO3(aq) + NaN3(aq) → AgN3(s) + NaNO3(aq)

X-ray crystallography shows that AgN3 is a coordination polymer with square planar Ag+ coordinated by four azide ligands. Correspondingly, each end of each azide ligand is connected to a pair of Ag+ centers. The structure consists of two-dimensional AgN3 layers stacked one on top of the other, with weaker Ag–N bonds between layers. The coordination of Ag+ can alternatively be described as highly distorted 4 + 2 octahedral, the two more distant nitrogen atoms being part of the layers above and below. [3]

Silver-azide-high-T-single-layer-3D-balls.png Silver-azide-high-T-layer-stacking-3D-balls.png Silver-azide-high-T-Ag-coordination-3D-balls-A.png Silver-azide-high-T-N-coordination-3D-balls-B.png
Part of a layerLayer stacking4 + 2 coordination of Ag+2 + 1 coordination of N in N3

In its most characteristic reaction, the solid decomposes explosively, releasing nitrogen gas:

2 AgN3(s) → 3 N2(g) + 2 Ag(s)

The first step in this decomposition is the production of free electrons and azide radicals; thus the reaction rate is increased by the addition of semiconducting oxides. [4] Pure silver azide explodes at 340  °C, but the presence of impurities lowers this down to 270 °C. [5] This reaction has a lower activation energy and initial delay than the corresponding decomposition of lead azide. [6]

Safety

AgN3, like most heavy metal azides, is a dangerous primary explosive. Decomposition can be triggered by exposure to ultraviolet light or by impact. [2] Ceric ammonium nitrate [NH4]2[Ce(NO3)6] is used as an oxidising agent to destroy AgN3 in spills. [5]

See also

Related Research Articles

<span class="mw-page-title-main">Nitrogen</span> Chemical element, symbol N and atomic number 7

Nitrogen is a chemical element; it has symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at seventh in total abundance in the Milky Way and the Solar System. At standard temperature and pressure, two atoms of the element bond to form N2, a colorless and odorless diatomic gas. N2 forms about 78% of Earth's atmosphere, making it the most abundant uncombined element in air. Because of the volatility of nitrogen compounds, nitrogen is relatively rare in the solid parts of the Earth.

<span class="mw-page-title-main">Silver nitrate</span> Chemical compound

Silver nitrate is an inorganic compound with chemical formula AgNO
3
. It is a versatile precursor to many other silver compounds, such as those used in photography. It is far less sensitive to light than the halides. It was once called lunar caustic because silver was called luna by ancient alchemists who associated silver with the moon. In solid silver nitrate, the silver ions are three-coordinated in a trigonal planar arrangement.

In chemistry, azide is a linear, polyatomic anion with the formula N−3 and structure N=N+=N. It is the conjugate base of hydrazoic acid HN3. Organic azides are organic compounds with the formula RN3, containing the azide functional group. The dominant application of azides is as a propellant in air bags.

<span class="mw-page-title-main">Silver chloride</span> Chemical compound with the formula AgCl

Silver chloride is a chemical compound with the chemical formula AgCl. This white crystalline solid is well known for its low solubility in water and its sensitivity to light. Upon illumination or heating, silver chloride converts to silver, which is signaled by grey to black or purplish coloration in some samples. AgCl occurs naturally as a mineral chlorargyrite.

<span class="mw-page-title-main">Sodium azide</span> Chemical compound

Sodium azide is an inorganic compound with the formula NaN3. This colorless salt is the gas-forming component in some car airbag systems. It is used for the preparation of other azide compounds. It is an ionic substance, is highly soluble in water, and is very acutely poisonous.

<span class="mw-page-title-main">Hydrazoic acid</span> Unstable and toxic chemical compound

Hydrazoic acid, also known as hydrogen azide, azic acid or azoimide, is a compound with the chemical formula HN3. It is a colorless, volatile, and explosive liquid at room temperature and pressure. It is a compound of nitrogen and hydrogen, and is therefore a pnictogen hydride. The oxidation state of the nitrogen atoms in hydrazoic acid is fractional and is -1/3. It was first isolated in 1890 by Theodor Curtius. The acid has few applications, but its conjugate base, the azide ion, is useful in specialized processes.

<span class="mw-page-title-main">1,3,5-Triazido-2,4,6-trinitrobenzene</span> Chemical compound

1,3,5-Triazido-2,4,6-trinitrobenzene, also known as TATNB (triazidotrinitrobenzene) and TNTAZB (trinitrotriazidobenzene), is an aromatic high explosive composed of a benzene ring with three azido groups (-N3) and three nitro groups (-NO2) alternating around the ring, giving the chemical formula C6(N3)3(NO2)3. Its detonation velocity is 7,350 meters per second, which is comparable to TATB (triaminotrinitrobenzene).

<span class="mw-page-title-main">Silver carbonate</span> Chemical compound

Silver carbonate is the chemical compound with the formula Ag2CO3. This salt is yellow but typical samples are grayish due to the presence of elemental silver. It is poorly soluble in water, like most transition metal carbonates.

<span class="mw-page-title-main">Zinc nitrate</span> Chemical compound

Zinc nitrate is an inorganic chemical compound with the formula Zn(NO3)2. This colorless, crystalline salt is highly deliquescent. It is typically encountered as a hexahydrate Zn(NO3)2·6H2O. It is soluble in both water and alcohol.

The chemical element nitrogen is one of the most abundant elements in the universe and can form many compounds. It can take several oxidation states; but the most common oxidation states are -3 and +3. Nitrogen can form nitride and nitrate ions. It also forms a part of nitric acid and nitrate salts. Nitrogen compounds also have an important role in organic chemistry, as nitrogen is part of proteins, amino acids and adenosine triphosphate.

<span class="mw-page-title-main">Silver compounds</span> Chemical compounds containing silver

Silver is a relatively unreactive metal, although it can form several compounds. The common oxidation states of silver are (in order of commonness): +1 (the most stable state; for example, silver nitrate, AgNO3); +2 (highly oxidising; for example, silver(II) fluoride, AgF2); and even very rarely +3 (extreme oxidising; for example, potassium tetrafluoroargentate(III), KAgF4). The +3 state requires very strong oxidising agents to attain, such as fluorine or peroxodisulfate, and some silver(III) compounds react with atmospheric moisture and attack glass. Indeed, silver(III) fluoride is usually obtained by reacting silver or silver monofluoride with the strongest known oxidizing agent, krypton difluoride.

<span class="mw-page-title-main">Lithium azide</span> Chemical compound

Lithium azide is the lithium salt of hydrazoic acid. It is an unstable and toxic compound that decomposes into lithium and nitrogen when heated.

<span class="mw-page-title-main">Silicon tetraazide</span> Chemical compound

Silicon tetraazide is a thermally unstable binary compound of silicon and nitrogen with a nitrogen content of 85.7%. This high-energy compound combusts spontaneously and can only be studied in a solution. A further coordination to a six-fold coordinated structure such as a hexaazidosilicate ion [Si(N3)6]2− or as an adduct with bicationic ligands Si(N3)4·L2 will result in relatively stable, crystalline solids that can be handled at room temperature.

<span class="mw-page-title-main">Bromine azide</span> Chemical compound

Bromine azide is an explosive inorganic compound with the formula BrN3. It has been described as a crystal or a red liquid at room temperature. It is extremely sensitive to small variations in temperature and pressure, with explosions occurring at Δp ≥ 0.05 Torr and also upon crystallization, thus extreme caution must be observed when working with this chemical.

Silver hyponitrite is an ionic compound with formula Ag2N2O2 or (Ag+
)2[ON=NO]2−, containing monovalent silver cations and hyponitrite anions. It is a bright canary yellow solid practically insoluble in water and most organic solvents, including DMF and DMSO.

<span class="mw-page-title-main">Iodine azide</span> Chemical compound

Iodine azide is an explosive inorganic compound, which in ordinary conditions is a yellow solid. Formally, it is an inter-pseudohalogen.

<span class="mw-page-title-main">Boron triazide</span> Chemical compound

Boron triazide, also known as triazidoborane, is a thermally unstable compound of boron and nitrogen with a nitrogen content of 92.1 %. Formally, it is the triazido derivative of borane and is a covalent inorganic azide. The high-energy compound, which has the propensity to undergo spontaneous explosive decomposition, was first described in 1954 by Egon Wiberg and Horst Michaud of the University of Munich.

Silver chlorite is a chemical compound with the formula AgClO2. This slightly yellow solid is shock sensitive and has an orthorhombic crystal structure.

Cobalt compounds are chemical compounds formed by cobalt with other elements.

Homoleptic azido compounds are chemical compounds in which the only anion or ligand is the azide group, -N3. The breadth of homoleptic azide compounds spans nearly the entire periodic table. With rare exceptions azido compounds are highly shock sensitive and need to be handled with the upmost caution. Binary azide compounds can take on several different structures including discrete compounds, or one- two, and three-dimensional nets, leading some to dub them as "polyazides". Reactivity studies of azide compounds are relatively limited due to how sensitive they can be. The sensitivity of these compounds tends to be correlated with the amount of ionic or covalent character the azide-element bond has, with ionic character being far more stable than covalent character. Therefore, compounds such as silver or sodium azide – which have strong ionic character – tend to possess more synthetic utility than their covalent counterparts. A few other notable exceptions include polymeric networks which possess unique magnetic properties, group 13 azides which unlike most other azides decompose to nitride compounds (important materials for semiconductors), other limited uses as synthetic reagents for the transfer for azide groups, or interest in high energy density materials.

References

  1. Marr H.E. III.; Stanford R.H. Jr. (1962). "The unit-cell dimensions of silver azide". Acta Crystallographica. 15 (12): 1313–1314. Bibcode:1962AcCry..15.1313M. doi:10.1107/S0365110X62003497.
  2. 1 2 Robert Matyas, Jiri Pachman (2013). Primary Explosives (1st ed.). Springer. p. 93. ISBN   978-3-642-28435-9.
  3. Schmidt, C. L. Dinnebier, R.; Wedig, U.; Jansen, M. (2007). "Crystal Structure and Chemical Bonding of the High-Temperature Phase of AgN3". Inorganic Chemistry. 46 (3): 907–916. doi:10.1021/ic061963n. PMID   17257034.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  4. Andrew Knox Galwey; Michael E. Brown (1999). Thermal decomposition of ionic solids (vol.86 of Studies in physical and theoretical chemistry. Elsevier. p. 335. ISBN   978-0-444-82437-0.
  5. 1 2 Margaret-Ann Armour (2003). Hazardous laboratory chemicals disposal guide, Environmental Chemistry and Toxicology (3rd ed.). CRC Press. p. 452. ISBN   978-1-56670-567-7.
  6. Jehuda Yinon; Shmuel Zitrin (1996). Modern Methods and Applications in Analysis of Explosives. John Wiley and Sons. pp. 15–16. ISBN   978-0-471-96562-6.