Styphnic acid
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| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 470483322
| Name = Styphnic acid
| ImageFile_Ref = {{chemboximage|correct|??}}
| ImageFile = Styphnic_acid_structure01.svg
| ImageName = Styphnic acid
| ImageSize = 150px
| ImageFileL1 = Styphnic acid Ball and Stick.png
| ImageSizeL1 = 140px
| ImageFileR1 = Styphnic acid Space Fill.png
| ImageSizeR1 = 140px
| PIN = 2,4,6-Trinitrobenzene-1,3-diol
|Section1={{Chembox Identifiers
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 6465
| PubChem = 6721
| InChI = 1/C6H3N3O8/c10-5-2(7(12)13)1-3(8(14)15)6(11)4(5)9(16)17/h1,10-11H
| InChIKey = IXHMHWIBCIYOAZ-UHFFFAOYAQ
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C6H3N3O8/c10-5-2(7(12)13)1-3(8(14)15)6(11)4(5)9(16)17/h1,10-11H
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = IXHMHWIBCIYOAZ-UHFFFAOYSA-N
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo = 82-71-3
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = R4TJB1U00D
| UNNumber = 0219 – Dry or wetted with < 20% water/alcohol
0394 – Wetted with >= 20% water/alcohol
| SMILES = c1c(c(c(c(c1[N+](=O)[O-])O)[N+](=O)[O-])O)[N+](=O)[O-]
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|Section2={{Chembox Properties
| Formula = C6H3N3O8
| MolarMass = 245.11 g/mol
| Density = 1.829 g/cm3
| MeltingPtC = 180
| BoilingPt = decomposes
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Styphnic acid (from Greek stryphnos "astringent"Alexander Senning (2006). {{Google books|Fl4sdCYrq3cC|Elsevier's Dictionary of Chemoetymology: The Whys and Whences of Chemical Nomenclature and Terminology|page=375}}), or 2,4,6-trinitro-1,3-benzenediol, is a yellow astringent acid that forms hexagonal crystals. It is used in the manufacture of dyes, pigments, inks, medicines, and explosives such as lead styphnate. It is itself a low-sensitivity explosive, similar to picric acid, but explodes upon rapid heating.{{cite book |last1=Armarego |first1=W.L.F. |last2=Chai |first2=C.L.L. |title=Purification of Laboratory Chemicals |url=https://books.google.com/books?id=SYzm1tx2z3QC |publisher=Butterworth-Heinemann |date=2003 |page=353 |access-date=2015-05-20 |isbn=9780750675710}}
History
It was discovered in 1808 by Michel Eugène Chevreul who was researching ways of producing colorants from tropical logwoods.{{Cite book |url=https://books.google.com/books?id=L3T_QPcDkX4C&pg=PA246 |title=Annales de chimie |date=1808 |publisher=Masson |language=fr}} Upon boiling Pernambuco wood extract with nitric acid he filtered crystals understood to be styphnic acid in an impure form.{{Cite book |last=Gmelin |first=Leopold |url=https://books.google.com/books?id=rfE4AAAAMAAJ&pg=PA228 |title=Hand Book of Chemistry |date=1848 |publisher=Cavendish society |language=en}} In mid-1840s chemists purified and systematically studied the substance with Rudolf Christian Böttger and Heinrich Will giving its modern name,{{Cite journal |last=Böttger |first=Rudolph |last2=Will |first2=Heinrich |date=January 1846 |title=Ueber eine neue, der Pikrinsäure nahestehende Säure |url=https://chemistry-europe.onlinelibrary.wiley.com/doi/10.1002/jlac.18460580302 |journal=Justus Liebigs Annalen der Chemie |language=en |volume=58 |issue=3 |pages=273–300 |doi=10.1002/jlac.18460580302 |issn=0075-4617}} while in 1871 J. Schreder proved that it is trinitroresorcinol.{{Cite journal |last=Schreder |first=J. |date=January 1871 |title=Ueber die Oxypikrinsäure (Styphninsäure) |url=https://chemistry-europe.onlinelibrary.wiley.com/doi/10.1002/jlac.18711580207 |journal=Justus Liebigs Annalen der Chemie |language=en |volume=158 |issue=2 |pages=244–253 |doi=10.1002/jlac.18711580207 |issn=0075-4617|url-access=subscription }}{{Cite book |last=Roscoe |first=Henry Enfield |url=https://books.google.com/books?id=HnfN90Fi0XgC&pg=PA144 |title=The chemistry of the hydrocarbons and their derivatives, or Organic chemistry. 1882-1892. 6 v |date=1887 |publisher=D. Appleton |language=en}}
Preparation and chemistry
It may be prepared by the nitration of resorcinol with a mixture of nitric and sulfuric acid.{{cite web |last=Barros |first=Sam |title=PowerLabs Styphnic Acid Synthesis! |url=http://www.powerlabs.org/chemlabs/styphnic.htm |publisher=powerlabs.org |access-date=2015-05-20}}
This compound is an example of a trinitrophenol.
Like picric acid, it is a moderately strong acid, capable of displacing carbon dioxide from solutions of sodium carbonate, for example.
It may be reacted with weakly basic oxides, such as those of lead and silver, to form the corresponding salts.
The solubility of picric acid and styphnic acid in water is less than their corresponding mono- and di-nitro compounds, and far less than their non-nitrated precursor phenols, so they may be purified by fractional crystallisation.
References
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