Gallic acid

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Gallic acid
Gallic acid
General
Systematic name 3,4,5-hydroxybenzoic acid
Other names Gallic acid
Molecular formula C7H6O5
SMILES Oc1cc(cc(O)c1O)C(O)=O
Molar mass 170.12 g/mol
Appearance White, yellowish-white, or
pale fawn-colored crystals.
CAS number [149-91-7] (Anhydrous)
[5995-86-8] (Monohydrate)
Properties
Density and phase 1.7 g/cm3 (anhydrous)
Solubility in water 1.1g/100ml water @ 20C (anhydrous)
Melting point 250°C (523 K)
Boiling point ?°C (? K)
Acidity (pKa) COOH: 4.5, OH: 10.
Chiral rotation [α]D
Structure
Crystal structure ?
Dipole moment ? D
Hazards
MSDS External MSDS]
Main hazards Irritant
NFPA 704
NFPA 704
fire diamond
NFPA 704 four-colored diamondHealth 1: Exposure would cause irritation but only minor residual injury. E.g. turpentineFlammability 0: Will not burn. E.g. waterInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
1
0
0
Flash point ?°C
R/S statement R: ?
S: ?
RTECS number ?
Supplementary data page
Structure and
properties
n, εr, etc.
Thermodynamic
data
Phase behaviour
Solid, liquid, gas
Spectral data UV, IR, NMR, MS
Related compounds
Related phenols,
carboxylic acids
?
Related compounds Benzoic acid, Phenol
Except where noted otherwise, data are given for
materials in their standard state (at 25 °C, 100 kPa)
Infobox disclaimer and references

Gallic acid is an organic acid, also known as 3,4,5-trihydroxybenzoic acid, found in gallnuts, sumac, witch hazel, tea leaves, oak bark, and other plants. The chemical formula is C6H2(OH)3CO2H. Gallic acid is found both free and as part of tannins. It is commonly used in the pharmaceutical industry. Gallic acid can also be used to synthesize the hallucinogenic alkaloid, mescaline, also known as 3,4,5-trimethoxyphenethylamine.

Salts and esters of gallic acid are termed gallates.

Gallic acid was one of the substances used by Angelo Mai among other early investigators of palimpsests to clear the top layer of text off and reveal hidden manuscripts underneath. Mai was the first to employ it, but did so "with a heavy hand," often damanging manuscripts for future study.

See also

External link

References

  • LD Reynolds and NG Wilson, “Scribes and Scholars” 3rd Ed. Oxford: 1991. pp193–4.

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