Picric acid

Structural formula
General
Surname	Picric acid
other names	2-amino-4,6-dinitrophenol PICRAMIC ACID ( INCI )
Molecular formula	C 6 H 5 N 3 O 5
Brief description	red crystals
External identifiers / databases
CAS number 96-91-3 EC number 202-544-6 ECHA InfoCard 100.002.314 PubChem 4921319 Wikidata Q283711
properties
Molar mass	199.12 g mol −1
Physical state	firmly
density	1.75 g cm −3
Melting point	168 ° C
pK s value	4.6
solubility	0.65 g l −1 in water (25 ° C) soluble in benzene , glacial acetic acid , ethanol and aniline
safety instructions
GHS hazard labeling from  Regulation (EC) No. 1272/2008 (CLP) , expanded if necessary danger H and P phrases H: 201-332-312-302-412 P: ?
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

The picramic acid ( 2-amino-4,6-dinitrophenol ) is an explosive organic nitro phenol which differs from the picric acid is derived.

Presentation and extraction

The compound can be obtained by a partial reduction from picric acid using sodium hydrogen sulfide , ammonium sulfide or copper and hydrazine .

properties

Picramic acid is a crystalline solid. The connection is explosive when dry due to impact, friction, heat and other ignition sources and is subject to the Explosives Act . The explosion is very violent, releasing large amounts of gas. A desensitization is possible with 20% water.

Table with important explosion-relevant properties:

Educational energy	−1168.0 kJ kg −1
Enthalpy of formation	−1249.0 kJ kg −1
Oxygen balance	−76.3%
Nitrogen content	21.11%
Normal gas volume	961 l kg −1
Explosion heat	2630 kJ kg −1 (H 2 O (l)) 2509 kJ kg −1 (H 2 O (g))
Specific energy	668 kJ kg −1 (68.1 mt / kg)
Lead block bulge	16.6 cm 3 g −1
Deflagration point	240 ° C
Steel sleeve test	Limit diameter 2.5 mm
Sensitivity to impact	34 Nm
Rubbing sensitivity	no reaction up to 353 N.

use

After diazotization , the initial explosive diazodinitrophenol can be obtained from the compound . The compound also serves as a starting material for azo dyes , as an indicator and as an oxidative hair dye.

Individual evidence

1. ↑ Entry on PICRAMIC ACID in the CosIng database of the EU Commission, accessed on March 21, 2020.
2. ↑ ^{a b c d} Entry on picric acid. In: Römpp Online . Georg Thieme Verlag, accessed on March 10, 2014.
3. ↑ Entry at guidechem.com
4. ↑ ^{a b c d e f g h i j k l m n o} Köhler, J .; Meyer, R .; Homburg, A .: Explosivstoffe , tenth, completely revised edition, Wiley-VCH, Weinheim 2008, p. 233, ISBN 978-3-527-32009-7 .
5. ↑ Springer, A .; Jones, HC: A Study of the Conductivity and Dissociation of Certain Organic Acids in Aqueous Solution at Different Temperatures , in: Amer. Chem. J. 48 (1912) pp. 411-452 ( pdf ).
6. ↑ Rose, AR; Sherwin, CP: Surface Tension as a Factor in Detoxication , in: J. Biol. Chem. 68 (1926) pp. 565-573.
7. ^ Entry on 2-amino-4,6-dinitrophenol in the GESTIS substance database of the IFA , accessed on February 1, 2016(JavaScript required) .
8. ↑ Entry on 2-amino-4,6-dinitrophenol in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on August 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
9. ↑ ^{a b c} Roth, L .; Weller, U .: Hazardous Chemical Reactions , 65th supplement, ecomed-Verlag 2011.
10. ↑ Explosives Act (Germany), Appendix I, List of explosive substances to which the law applies in full.