Catechol

Catechol
Skeletal formula
Pyrocatechol
Ball-and-stick model
Ball-and-stick model
Names
Preferred IUPAC name
Benzene-1,2-diol[1]
Other names
Pyrocatechol[1]
1,2-Benzenediol
2-Hydroxyphenol
1,2-Dihydroxybenzene
o-Benzenediol
o-Dihydroxybenzene
Identifiers
3D model (JSmol)
471401
ChEBI
ChEMBL
ChemSpider
DrugBank
ECHA InfoCard 100.004.025 Edit this at Wikidata
EC Number
  • 204-427-5
2936
KEGG
RTECS number
  • UX1050000
UNII
  • Oc1c(O)cccc1
Properties
C6H6O2
Molar mass 110.112 g·mol−1
Appearance white to brown feathery crystals
Odor faint, phenolic odor
Density 1.344 g/cm3, solid
Melting point 105 °C (221 °F; 378 K)
Boiling point 245.5 °C (473.9 °F; 518.6 K) (sublimes)
312 g/L at 20 °C[2]
Solubility very soluble in pyridine
soluble in chloroform, benzene, CCl4, ether, ethyl acetate
log P 0.88
Vapor pressure 20 Pa (20 °C)
Acidity (pKa) 9.45, 12.8
−6.876×10−5 cm3/mol
1.604
2.62±0.03 D [3]
Structure
monoclinic
Thermochemistry
−354.1 kJ·mol−1
Enthalpy of fusion fHfus)
22.8 kJ·mol−1 (at melting point)
Hazards
GHS labelling:
GHS06: ToxicGHS08: Health hazardGHS05: Corrosive
Danger
H301, H311, H315, H317, H318, H332, H341
P261, P301, P302, P305, P310, P312, P330, P331, P338, P351, P352
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasFlammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
3
1
0
Flash point 127 °C (261 °F; 400 K)
510 °C (950 °F; 783 K)
Explosive limits 1.4%–?[4]
Lethal dose or concentration (LD, LC):
300 mg/kg (rat, oral)
NIOSH (US health exposure limits):
PEL (Permissible)
none[4]
REL (Recommended)
TWA 5 ppm (20 mg/m3) [skin][4]
IDLH (Immediate danger)
N.D.[4]
Safety data sheet (SDS) Sigma-Aldrich
Related compounds
Related benzenediols
Resorcinol
Hydroquinone
Related compounds
1,2-benzoquinone
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Catechol (/ˈkætɪɒl/ or /ˈkætɪkɒl/), also known as pyrocatechol or 1,2-dihydroxybenzene, is an organic compound with the molecular formula C6H4(OH)2. It is the ortho isomer of the three isomeric benzenediols. This colorless compound occurs naturally in trace amounts. It was first discovered by destructive distillation of the plant extract catechin. About 20,000 tonnes of catechol are now synthetically produced annually as a commodity organic chemical, mainly as a precursor to pesticides, flavors, and fragrances. Small amounts of catechol occur in fruits and vegetables.[2]

  1. ^ a b "Front Matter". Nomenclature of Organic Chemistry: IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. p. 691. doi:10.1039/9781849733069-FP001. ISBN 978-0-85404-182-4.
  2. ^ a b Cite error: The named reference Ullmann was invoked but never defined (see the help page).
  3. ^ Lander, John J.; Svirbely, W. J. (1945). "The Dipole Moments of Catechol, Resorcinol and Hydroquinone". Journal of the American Chemical Society. 67 (2): 322–324. doi:10.1021/ja01218a051.
  4. ^ a b c d NIOSH Pocket Guide to Chemical Hazards. "#0109". National Institute for Occupational Safety and Health (NIOSH).