Silver azide

Chembox new
ImageFile = Silver-azide-high-T-single-layer-3D-vdW.png Name = Silver azide
OtherNames =
Section1 = Chembox Identifiers
CASNo = 13863-88-2
Section2 = Chembox Properties
Formula = AgN₃
MolarMass = 149.888 g/mol
Appearance = colourless solid
Density = 4.42 g/cm³, solid
MeltingPt = 250 °C, explosive
BoilingPt = decomp.
Solvent = other solvents
SolubleOther = 2.0x10^-8 g/L

Silver azide is the chemical compound with the formula AgN₃. This colourless solid is a well known explosive.

Preparation, structure, decomposition

Silver azide can be prepared by treating an aqueous solution of silver nitrate with sodium azide. The silver azide precipitates as a white solid.: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. [ cite journal | author = Schmidt, C. L. Dinnebier, R.; Wedig, U.; Jansen, M. | title = Crystal Structure and Chemical Bonding of the High-Temperature Phase of AgN₃ | journal = Inorganic Chemistry | year = 2007 | volume = 46 | pages = 907-916 | doi = 10.1021/ic061963n ] .

In its most characteristic reaction, the solid decomposes explosively, releasing nitrogen gas:: 2 AgN₃(s) → 3 N₂(g) + 2 Ag(s)

afety

AgN₃, like most heavy metal azides, can be dangerously explosive.

References