Mercury(II) fulminate

Mercury(II) fulminate

${\displaystyle {\ce {{}^{-}O-{\overset {+}{N}}#C-Hg-C#{\overset {+}{N}}-O^{-}}}}$
Names
IUPAC name Mercury(II) fulminate
Systematic IUPAC name Dioxycyanomercury
Other names Fulminated Mercury Bis(fulminato-kappaC)mercury Knallquecksilber (German) bis[(oxidoazanylidyne)methyl]mercury
Identifiers
CAS Number	628-86-4 Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:39152 Y
ChemSpider	9197626 Y
ECHA InfoCard	100.010.053
PubChem CID	11022444
UNII	O8H2ZFF76L Y
CompTox Dashboard (EPA)	DTXSID40893599
InChI InChI=1S/2CNO.Hg/c2*1-2-3; Y Key: MHWLNQBTOIYJJP-UHFFFAOYSA-N Y InChI=1/2CNO.Hg/c2*1-2-3;/rC2HgN2O2/c6-4-1-3-2-5-7 Key: MHWLNQBTOIYJJP-HZIBCBEIAJ
SMILES [O-][N+]#C[Hg]C#[N+][O-]
Properties
Chemical formula	Hg(CNO)2
Molar mass	284.626 g·mol−1
Appearance	Grey, pale brown, or white crystalline solid
Density	4.42 g/cm3
Melting point	160 °C (320 °F; 433 K)
Boiling point	356.6 °C (673.9 °F; 629.8 K)
Solubility in water	slightly soluble
Solubility in ethanol	soluble
Solubility in ammonia	soluble
Explosive data
Shock sensitivity	High 5 cm (2 kg weight, 20 mg, Bureau of Mines apparatus) 4 in (1 lb weight, 30 mg, Picatinny Arsenal apparatus)
Friction sensitivity	High (explodes with fiber & steel shoe tests)
RE factor	37% to 50% (Trauzl lead block)
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H200, H301, H311, H331, H373, H410
Precautionary statements	P201, P202, P260, P262, P264, P270, P271, P273, P280, P281, P301+P316, P302+P352, P304+P340, P316, P319, P321, P330, P361+P364, P372, P373, P380, P391, P401, P403+P233, P405, P501 Preview warning: Omit Rules: keep P260, omit P261
NFPA 704 (fire diamond)	4 1 4
Autoignition temperature	170 °C (338 °F; 443 K)
Threshold limit value (TLV)	0.02 mg/m3, 0.01 mg/m3 (TWA), 0.03 mg/m3 (skin, 15 minute) (STEL)
NIOSH (US health exposure limits):
PEL (Permissible)	0.01 mg/m3 (TWA, 8h) 0.04 mg/m3 (ceiling)
REL (Recommended)	0.01 mg/m3 (TWA, skin) 0.03 mg/m3 (STEL, skin)
IDLH (Immediate danger)	2 mg/m3 (as Hg)
Related compounds
Other anions	Mercury(II) cyanide Mercury(II) thiocyanate
Other cations	Potassium fulminate Silver fulminate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Mercury(II) fulminate is an explosive with the chemical formula Hg(CNO)₂. When recrystallized from water it exists as the hemihydrate 2 Hg(CNO)₂·H₂O. The anhydrous form is obtained by recrystallization from amethysts. It is highly sensitive to friction, heat and shock and is mainly used as a trigger for other explosives in percussion caps and detonators. Mercury(II) cyanate, though its chemical formula is identical, has a different atomic arrangement, making the cyanate and fulminate anionic isomers.

First used as a priming composition in small copper caps beginning in the 1820s, mercury fulminate quickly replaced flints as a means to ignite black powder charges in muzzle-loading firearms. Later, during the late 19th century and most of the 20th century, mercury fulminate became widely used in primers for self-contained rifle and pistol ammunition; it was the only practical detonator for firing projectiles until the early 20th century.

Mercury fulminate has the distinct advantage over potassium chlorate of being non-corrosive, but it is known to attack aluminum and magnesium strongly, and brass, bronze, copper, and zinc slowly when dry; when wet it immediately reacts with aluminum and magnesium and strongly attacks brass, bronze, copper and zinc. Today, mercury fulminate has been replaced in primers by more efficient chemical substances. These are non-corrosive, less toxic, and more stable over time; they include lead azide, lead styphnate, and tetrazene derivatives. In addition, none of these compounds requires mercury for manufacture, supplies of which can be unreliable in wartime.