# Fulminate

 ${\displaystyle {\ce {^{-}\!C{\equiv }{\overset {+}{N}}-O^{-}}}}$ Structural formula of the fulminate ion

Fulminates are chemical compounds which include the fulminate ion. The fulminate ion, CNO
is a pseudohalic ion, acting like a halogen with its charge and reactivity. Due to the instability of the ion, fulminate salts are friction-sensitive explosives. The best known is mercury(II) fulminate, which has been used as a primary explosive in detonators. Fulminates can be formed from metals, such as silver and mercury, dissolved in nitric acid and reacted with ethanol. The weak single nitrogen-oxygen bond is responsible for their instability. Nitrogen very easily forms a stable triple bond to another nitrogen atom, forming nitrogen gas.

## Historical notes

Fulminates were discovered by Edward Charles Howard in 1800.[1][2][3] The use of fulminates for firearms was first demonstrated by a Scottish minister, A. J. Forsyth, who patented his scent-bottle lock in 1807; this was a small container filled with fulminate of mercury.[4][5] Joshua Shaw determined how to encapsulate them in metal to form a percussion cap, but did not patent his invention until 1822.

In the 1820s, the organic chemist Justus Liebig discovered silver fulminate (Ag-CNO) and Friedrich Wöhler discovered silver cyanate (Ag-OCN). They have different properties but the same chemical composition, which led to an acrid dispute finally resolved by Jöns Jakob Berzelius concept of isomers.[6]