Silver azide is the
chemical compound
A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one ele ...
with the
formula . It is a
silver
Silver is a chemical element with the Symbol (chemistry), symbol Ag (from the Latin ', derived from the Proto-Indo-European wikt:Reconstruction:Proto-Indo-European/h₂erǵ-, ''h₂erǵ'': "shiny" or "white") and atomic number 47. A soft, whi ...
(I) salt of
hydrazoic acid. It forms a colorless crystals. It is a well-known
explosive
An explosive (or explosive material) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An exp ...
.
Structure and chemistry
Silver azide can be prepared by treating an
aqueous
An aqueous solution is a solution in which the solvent is water. It is mostly shown in chemical equations by appending (aq) to the relevant chemical formula. For example, a solution of table salt, or sodium chloride (NaCl), in water would ...
solution of
silver nitrate with
sodium azide.
/ref> The silver azide precipitates as a white solid, leaving sodium nitrate in solution.
:
X-ray crystallography
X-ray crystallography is the experimental science determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to diffract into many specific directions. By measuring the angle ...
shows that is a coordination polymer with square planar coordinated by four azide ligand
In coordination chemistry, a ligand is an ion or molecule ( functional group) that binds to a central metal atom to form a coordination complex. The bonding with the metal generally involves formal donation of one or more of the ligand's ele ...
s. Correspondingly, each end of each azide ligand is connected to a pair of centers. The structure consists of two-dimensional layers stacked one on top of the other, with weaker Ag–N bonds between layers. The coordination of can alternatively be described as highly distorted 4 + 2 octahedral, the two more distant nitrogen atoms being part of the layers above and below.
In its most characteristic reaction, the solid decomposes explosively, releasing nitrogen gas:
:
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. Pure silver azide explodes at 340 °C
The degree Celsius is the unit of temperature on the Celsius scale (originally known as the centigrade scale outside Sweden), one of two temperature scales used in the International System of Units (SI), the other being the Kelvin scale. The d ...
, but the presence of impurities lowers this down to 270 °C.
Safety
, like most heavy metal azides, is a dangerous primary explosive. Decomposition can be triggered by exposure to ultraviolet
Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nm (with a corresponding frequency around 30 PHz) to 400 nm (750 THz), shorter than that of visible light, but longer than X-rays. UV radiati ...
light or by impact.
See also
* Silver nitride
References
{{Azides
Silver compounds
Azides
Explosive chemicals