Environmental Engineering Reference
In-Depth Information
C and under low
pressure, the products are collected on the surface cooled by liquid helium. The
decomposition reaction is below:
If the decomposition of hydrogen azide is below 1,000
°
6HN 3 !
7N 2 +H 2 + (NH) 4
Alkali metal azides do not explode. They decompose slowly.
2NaN 3 !
2Na + 3N 2 "
The decomposition of heavy metal azides is from the excitation of azide ion,
which produces an azido group. The decomposition of ground state azido group
into ground state N and N 2 is forbidden by the selected rules; while the decom-
position of ground state azido group into excited state N and N 2 is allowed by the
selected rules, but it needs 259 kJ/mol energy. This decomposition reaction is not
obvious at room temperature. The interaction of two azide groups is allowed by the
selected rules, and it is an exothermic process. The interaction of azide groups is
one important step of ionic azido solid compounds.
Silver azide, lead azide, etc., heavy metal azides are highly explosive. Lead azide
is very sensitive for impact, so it is used as a detonator. Generally, other azides are
nonexplosive. Sodium azide is most widely used. It is water decomposable, and the
hydrolysis product is diazoimide (HN 3 ). Aryl azides are colorful and relatively
stable solids. They explode when being impacted, and decompose when being
melted and release HN 3 . Sodium azide easily combines with lead or copper to
produce metal azides, which are highly explosive.
Azido compounds can inhibit the activity of cytochrome oxidase and other
enzymes, and cause phosphorylation and respiratory abnormality of cells. The main
acute toxicity of hydrazoic acid and its salts extremely lowers angiotasis by directly
impacting vascular smooth muscle. The effect is similar but stronger than nitrites.
The only difference is that azido alkane does not produce methemoglobin. Azido
compounds can stimulate breathing and enhance cardiac force. Large-dose azido
compounds elevate the blood pressure and cause convulsions, followed by sup-
pression and shock. In organic azido compounds, azidoethane and azidopentane are
effective antivascular tone agents. But several aryl azido compounds do not have
this effect.
6.1.2 Application of Azido Compound Liquids
6.1.2.1 Application of Azido Compounds in Cycloaddition Reaction
Organic azido compounds react with alkene, ketone, X
Y triple bonds, X=Y
double bonds, and alkyne to generate cycloaddition products
ve-membered
nitrogen-containing heterocyclic compounds. Under heating or catalysts, organic
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