Lead styphnate

Lead styphnate

200px
Names
IUPAC name Lead 2,4,6-trinitrobenzene-1,3-diolate
Other names Lead 2,4,6-trinitro-m-phenylene dioxide 1,3-Benzenediol, 2,4,6-trinitro-, lead(2+) salt (1:1) Lead tricinate Lead trinitroresorcinate Tricinat
Identifiers
CAS Number	15245-44-0 Y
ChemSpider	55674 N
EC Number	239-290-0
Jmol 3D model	Interactive image
PubChem	61789
UN number	0130
InChI InChI=1S/C6H3N3O8.Pb/c10-5-2(7(12)13)1-3(8(14)15)6(11)4(5)9(16)17;/h1,10-11H;/q;+2/p-2 N Key: WETZJIOEDGMBMA-UHFFFAOYSA-L N InChI=1/C6H3N3O8.Pb/c10-5-2(7(12)13)1-3(8(14)15)6(11)4(5)9(16)17;/h1,10-11H;/q;+2/p-2 Key: WETZJIOEDGMBMA-NUQVWONBAY
SMILES c1c(c(c(c(c1[N+](=O)[O-])[O-])[N+](=O)[O-])[O-])[N+](=O)[O-].[Pb+2]
Properties
Chemical formula	C6HN3O8Pb
Molar mass	450.288 g/mol
Density	3.06 to 3.1 g cm−3
Explosive data
Shock sensitivity	High
Friction sensitivity	High
Detonation velocity	5200 m/s
Vapor pressure	{{{value}}}
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

Lead styphnate (lead 2,4,6-trinitroresorcinate, C₆HN₃O₈Pb ), whose name is derived from styphnic acid, is an explosive used as a component in primer and detonator mixtures for less sensitive secondary explosives. Lead styphnate is only slightly soluble in water and methyl alcohol Samples of lead styphnate vary in color from yellow to gold, orange, reddish-brown, to brown. Lead styphnate is known in various polymorphs, hydrates, and basic salts. Normal lead styphnate monohydrate, monobasic lead styphnate, tribasic lead styphnate dihydrate, and pentabasic lead styphnate dehydrate as well as α, β polymorphs of lead styphnate exist.

Two forms of lead styphnate are six-sided monohydrate crystals and small rectangular crystals. Lead styphnate is particularly sensitive to fire and the discharge of static electricity. When dry, it can readily detonate by static discharges from the human body. The longer and narrower the crystals, the more susceptible lead styphnate is to static electricity. Lead styphnate does not react with metals and is less sensitive to shock and friction than mercury fulminate or lead azide. . It is stable in storage, even at elevated temperatures. As with other lead-containing compounds, lead styphnate is toxic owing to heavy metal poisoning.

Preparation

Although never substantiated, lead styphnate may have been discovered by Peter Griess (of Griess test fame) in 1874. In 1919, Edmund Herz first established a preparation of anhydrous normal lead styphnate by the reaction of magnesium styphnate with lead acetate in the presence of nitric acid.

{C₆N₃O₈}MgH₂O + Pb(CH₃CO₂)₂ → {C₆N₃O₈}PbH₂O + Mg(CH₃CO₂)₂

Structure

Normal lead styphnate exists as α and β polymorphs, both being monoclinic crystals. The lead centres are seven-coordinate and are bridged via oxygen bridges. The water molecule is coordinated to the metal and is also hydrogen-bonded to the anion. Many of the Pb-O distances are short, indicating some degree of covalency. The styphnate ions lie in approximately parallel planes linked by Pb atoms.

Properties

Its heat of formation is -835 kJ mol-1. The loss of water leads to the formation of a sensitive anhydrous material with a density of 2.9 g cm⁻³. The variation of colors remains unexplained. Lead Styphnate has a detonation velocity of 5.2 km/s and an explosion temperature of 265-280 °C after five seconds.

Applications

Lead styphnate is mainly used in small arm ammunition for military and commercial applications. It serves as a primary explosive with gunpowder, which will not ignite upon a simple impact. Lead styphnate is also used as primer in microthrusters for small satellite stationkeeping.

External links

• National Pollutant Inventory - Lead and Lead Compounds Fact Sheet