1,4-Benzoquinone

1,4-Benzoquinone
Skeletal formula
Skeletal formula
Space-filling model
Space-filling model
Names
Preferred IUPAC name
Cyclohexa-2,5-diene-1,4-dione[1]
Other names
1,4-Benzoquinone[1]
Benzoquinone
p-Benzoquinone
p-Quinone
Identifiers
3D model (JSmol)
3DMet
773967
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.003.097 Edit this at Wikidata
EC Number
  • 203-405-2
2741
KEGG
RTECS number
  • DK2625000
UNII
UN number 2587
  • InChI=1S/C6H4O2/c7-5-1-2-6(8)4-3-5/h1-4H checkY
    Key: AZQWKYJCGOJGHM-UHFFFAOYSA-N checkY
  • InChI=1/C6H4O2/c7-5-1-2-6(8)4-3-5/h1-4H
    Key: AZQWKYJCGOJGHM-UHFFFAOYAR
  • O=C\1\C=C/C(=O)/C=C/1
  • C1=CC(=O)C=CC1=O
Properties
C6H4O2
Molar mass 108.096 g·mol−1
Appearance Yellow solid
Odor Acrid, chlorine-like[2]
Density 1.318 g/cm3 at 20 °C
Melting point 115 °C (239 °F; 388 K)
Boiling point Sublimes
11 g/L (18 °C)
Solubility Slightly soluble in petroleum ether; soluble in acetone; 10% in ethanol, benzene, diethyl ether
Vapor pressure 0.1 mmHg (25 °C)[2]
−38.4·10−6 cm3/mol
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
 Toxic
GHS labelling:
GHS06: ToxicGHS07: Exclamation markGHS09: Environmental hazard
Danger
H301, H315, H319, H331, H335, H400
P261, P264, P270, P271, P273, P280, P301+P310, P302+P352, P304+P340, P305+P351+P338, P311, P312, P321, P330, P332+P313, P337+P313, P362, P391, P403+P233, P405, P501
Flash point 38 to 93 °C; 100 to 200 °F; 311 to 366 K[2]
Lethal dose or concentration (LD, LC):
296 mg/kg (mammal, subcutaneous)
93.8 mg/kg (mouse, subcutaneous)
8.5 mg/kg (mouse, IP)
5.6 mg/kg (rat)
130 mg/kg (rat, oral)
25 mg/kg (rat, IV)[3]
NIOSH (US health exposure limits):
PEL (Permissible)
 TWA 0.4 mg/m3 (0.1 ppm)[2]
REL (Recommended)
 TWA 0.4 mg/m3 (0.1 ppm)[2]
IDLH (Immediate danger)
 100 mg/m3[2]
Related compounds
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).
☒N verify (what is checkY☒N ?)

1,4-Benzoquinone, commonly known as para-quinone, is a chemical compound with the formula C6H4O2. In a pure state, it forms bright-yellow crystals with a characteristic irritating odor, resembling that of chlorine, bleach, and hot plastic or formaldehyde. This six-membered ring compound is the oxidized derivative of 1,4-hydroquinone.[4] The molecule is multifunctional: it exhibits properties of a ketone, being able to form oximes; an oxidant, forming the dihydroxy derivative; and an alkene, undergoing addition reactions, especially those typical for α,β-unsaturated ketones. 1,4-Benzoquinone is sensitive toward both strong mineral acids and alkali, which cause condensation and decomposition of the compound.[5][6]

  1. ^ a b Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. pp. 723–724. doi:10.1039/9781849733069-FP001. ISBN 978-0-85404-182-4.
  2. ^ a b c d e f NIOSH Pocket Guide to Chemical Hazards. "#0542". National Institute for Occupational Safety and Health (NIOSH).
  3. ^ "Quinone". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
  4. ^ Underwood, H. W. Jr.; Walsh, W. L. (1936). "Quinone". Organic Syntheses. 16: 73. doi:10.15227/orgsyn.002.0085; Collected Volumes, vol. 2, p. 553.
  5. ^ Patai, Saul; Rappoport, Zvi, eds. (1988). The Quinonoid Compounds: Vol. 1 (1988). doi:10.1002/9780470772119. ISBN 978-0-470-77211-9.
  6. ^ Patai, Saul; Rappoport, Zvi, eds. (1988). The Quinonoid Compounds: Vol. 2 (1988). doi:10.1002/9780470772126. ISBN 978-0-470-77212-6.