Dunnite

Not to be confused with dunite.

Dunnite, also known as Explosive D or systematically as ammonium picrate, is an explosive developed in 1906 by US Army Major Beverly W. Dunn, who later served as chief inspector of the Bureau of Transportation Explosives.^[2][3] Ammonium picrate is a salt formed by reacting picric acid and ammonia. It is chemically related to the more stable explosive trinitrotoluene (TNT).

Dunnite

Names
IUPAC name Ammonium 2,4,6-trinitrophenolate
Other names Ammonium picrate; Picratol; 2,4,6-Trinitrophenol ammonium salt; Ammonium picronitrate; Explosive D
Identifiers
CAS Number	131-74-8 Y
3D model (JSmol)	Interactive image
ChemSpider	8259 N
ECHA InfoCard	100.004.582
EC Number	205-038-3
PubChem CID	8577
UNII	4N99515C3Z Y
CompTox Dashboard (EPA)	DTXSID50872815
InChI InChI=1S/C6H3N3O7.H3N/c10-6-4(8(13)14)1-3(7(11)12)2-5(6)9(15)16;/h1-2,10H;1H3 N Key: PADMMUFPGNGRGI-UHFFFAOYSA-N N InChI=1/C6H3N3O7.H3N/c10-6-4(8(13)14)1-3(7(11)12)2-5(6)9(15)16;/h1-2,10H;1H3 Key: PADMMUFPGNGRGI-UHFFFAOYAZ
SMILES C1=C(C=C(C(=C1[N+](=O)[O-])[O-])[N+](=O)[O-])[N+](=O)[O-].[NH4+]
Properties
Chemical formula	C6H6N4O7
Molar mass	246.135 g·mol−1
Density	1.719 g/cm3[1]
Melting point	265 °C (509 °F; 538 K)[1]
Solubility in water	10 g/L (20 °C)
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H201, H315, H317, H319
Precautionary statements	P210, P230, P240, P250, P261, P264, P272, P280, P302+P352, P305+P351+P338, P321, P332+P313, P333+P313, P337+P313, P362, P363, P370+P380, P372, P373, P401, P501
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

History

Ammonium picrate was proposed for use as a component in gunpowder by Brugère and Abel as early as 1869: the former proposed to mix 54% of it with 46% of saltpetre while the latter, 60% with 40%.^[4] Their compositions gave less smoke and were more energetic than black powder but neither was adopted by any military, even though in the 1890s "semi-smokeless" powder compositions featuring ammonium picrates were sold commercially in the US.^[5] It also was a minor component of the Peyton powder made by the California Powder Works which was procured by the US military in the same period.^[5]

It was the first explosive used in an aerial bombing operation in military history, performed by Italian pilots in Libya in 1911.^[6] It was used extensively by the United States Navy during World War I.^[7]

Though Dunnite was generally considered an insensitive substance, by 1911 the United States Army had abandoned its use in favor of other alternatives.^[8] The Navy, however, used it in armor-piercing artillery shells and projectiles, and in coastal defense.

By the end of WWI a pound of ammonium picrate cost US government 64 cents, while TNT cost 26.5 c/lb, ammonium nitrate used in amatol only 17.5 c/lb and black powder about 25 c/lb.^[9]

Dunnite typically did not detonate on striking heavy armor. Rather, the encasing shell would penetrate the armor, after which the charge would be triggered by a base fuze.

During WWII, it was gradually replaced by RDX-based Composition A-3.^[10]

In 2008 caches of discarded Dunnite in remote locations were mistaken for rusty rocks at Cape Porcupine, Newfoundland and Labrador, Canada.^[11][12]

Dunnite can be used as a precursor to the highly stable explosive TATB (1,3,5-triamino-2,4,6-trinitrobenzene), by first dehydrating it to form picramide (attaching the ammonia as an amine group instead of an ion) and then further aminating it, using 1,1,1-trimethylhydrazinium iodide (TMHI) made from unsymmetrical dimethylhydrazine rocket fuel and methyl iodide. Thus, surplus materials that would have to be destroyed when no longer needed are converted into a high value explosive.^[13][14]