Hydroquinone

• Formula: C₆H₆O₂
• Molecular weight: 110.1106
• IUPAC Standard InChI: InChI=1S/C6H6O2/c7-5-1-2-6(8)4-3-5/h1-4,7-8H Copy

  
• IUPAC Standard InChIKey: QIGBRXMKCJKVMJ-UHFFFAOYSA-N Copy
• CAS Registry Number: 123-31-9
• Chemical structure:
  This structure is also available as a 2d Mol file or as a computed 3d SD file
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• Other names: 1,4-Benzenediol; p-Benzenediol; p-Dihydroxybenzene; p-Dioxybenzene; p-Hydroquinone; p-Hydroxyphenol; Arctuvin; Benzohydroquinone; Benzoquinol; Diak 5; Eldopaque; Eldoquin; Hidroquinone; Hydroquinol; HE 5; Phiaquin; Quinol; Tecquinol; Tenox HQ; 1,4-Dihydroxybenzene; 4-Hydroxyphenol; p-Dioxobenzene; Hydrochinone; Benzene, p-dihydroxy-; Black and White Bleaching Cream; Derma-Blanch; Hydrochinon; Hydroquinole; Idrochinone; NCI-C55834; Tequinol; USAF EK-356; 1,4-Dihydroxy-benzeen; 1,4-Dihydroxy-benzol; 1,4-Dihydroxybenzen; 1,4-Diidrobenzene; UN 2662; Dihydroquinone; Aida; Eldopacque; Eldopaque forte; Eldoquin forte; Solaquin forte; p-Dihydroquinone; Black & White Bleaching Cream; 1,4-Benzenediol (hydroquinone); Artra (Salt/Mix)
• Permanent link for this species. Use this link for bookmarking this species for future reference.
• Information on this page:
  • Gas phase thermochemistry data
  • Gas phase ion energetics data
  • IR Spectrum
  • UV/Visible spectrum
  • References
  • Notes
• Other data available:
  • Condensed phase thermochemistry data
  • Phase change data
  • Reaction thermochemistry data
  • Henry's Law data
  • Mass spectrum (electron ionization)
  • Gas Chromatography
• Data at other public NIST sites:
  • X-ray Photoelectron Spectroscopy Database, version 5.0
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Gas phase thermochemistry data

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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data compiled as indicated in comments:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DRB - Donald R. Burgess, Jr.
GT - Glushko Thermocenter, Russian Academy of Sciences, Moscow

Constant pressure heat capacity of gas

Gas phase ion energetics data

Go To: Top, Gas phase thermochemistry data, IR Spectrum, UV/Visible spectrum, References, Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data evaluated as indicated in comments:
L - Sharon G. Lias

Data compiled as indicated in comments:
B - John E. Bartmess
LBLHLM - Sharon G. Lias, John E. Bartmess, Joel F. Liebman, John L. Holmes, Rhoda D. Levin, and W. Gary Mallard
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi

View reactions leading to C₆H₆O₂⁺ (ion structure unspecified)

Ionization energy determinations

De-protonation reactions

C₆H₅O₂^- +  =

By formula: C₆H₅O₂^- + H⁺ = C₆H₆O₂

IR Spectrum

Go To: Top, Gas phase thermochemistry data, Gas phase ion energetics data, UV/Visible spectrum, References, Notes

Data compiled by: Coblentz Society, Inc.

• SOLID (0.5% IN KBr PELLET); BECKMAN IR-7 (GRATING); DIGITIZED BY NIST FROM HARD COPY (FROM TWO SEGMENTS); 4 cm^-1 resolution
• SOLID (SPLIT MULL); DOW KBr FOREPRISM-GRATING; DIGITIZED BY COBLENTZ SOCIETY (BATCH I) FROM HARD COPY; 2 cm^-1 resolution

Data compiled by: NIST Mass Spectrometry Data Center, William E. Wallace, director

• gas

UV/Visible spectrum

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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data compiled by: Victor Talrose, Eugeny B. Stern, Antonina A. Goncharova, Natalia A. Messineva, Natalia V. Trusova, Margarita V. Efimkina

Spectrum

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Additional Data

References

Go To: Top, Gas phase thermochemistry data, Gas phase ion energetics data, IR Spectrum, UV/Visible spectrum, Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Sabbah and Buluku, 1991
Sabbah, R.; Buluku, E.N.L.E., Thermodynamic study of three isomers of dihydroxybenzene, Can. J. Chem., 1991, 69, 481-488. [all data]

Pilcher and Sutton, 1956
Pilcher, G.; Sutton, L.E., The heats of combustion of quinol and p-benzoquinone and the thermodynamic quantities of the oxidation-reduction reaction, J. Chem. Soc., 1956, 2695-2700. [all data]

Parks, Manchester, et al., 1954
Parks, G.S.; Manchester, K.E.; Vaughan, L.M., Heats of combustion and formation of some alcohols, phenols, and ketones, J. Chem. Phys., 1954, 22, 2089-2090. [all data]

Pushin, 1954
Pushin, N.A., Heats of combustion and heats of formation of isomeric organic compounds, Bull. Soc. Chim. Belgrade, 1954, 19, 531-547. [all data]

Schreiner, 1925
Schreiner, E., Thermodynamics of the quinhydrone electrode and the chemical constant of hydrogen, Z. Phys. Chem., 1925, 117, 57-87. [all data]

Kudchadker S.A., 1979
Kudchadker S.A., Ideal gas thermodynamic properties of benzene diols: pyrocatechol, resorcinol, and hydroquinone, Thermochim. Acta, 1979, 30, 319-326. [all data]

Oikawa, Abe, et al., 1985
Oikawa, A.; Abe, H.; Mikami, N.; Ito, M., Electronic spectra and ionization potentials of rotational isomers of severaldDisubstituted benzenes, Chem. Phys. Lett., 1985, 116, 50. [all data]

Potapov, Kardash, et al., 1972
Potapov, V.K.; Kardash, I.E.; Sorokin, V.V.; Sokolov, S.A.; Evlasheva, T.I., Photoionization of heteroaromatic compounds, Khim. Vys. Energ., 1972, 6, 392. [all data]

Potapov and Sorokin, 1971
Potapov, V.K.; Sorokin, V.V., Photoionization and ion-molecule reactions in quinones and alcohols, High Energy Chem., 1971, 5, 435, In original 487. [all data]

Palmer, Moyes, et al., 1979
Palmer, M.H.; Moyes, W.; Speirs, M.; Ridyard, J.N.A., The electronic structure of substituted benzenes; ab initio calculations and photoelectron spectra for phenol, the methyl- and fluoro-derivatives, and the dihydroxybenzenes, J. Mol. Struct., 1979, 52, 293. [all data]

Fujio, McIver, et al., 1981
Fujio, M.; McIver, R.T., Jr.; Taft, R.W., Effects on the acidities of phenols from specific substituent-solvent interactions. Inherent substituent parameters from gas phase acidities, J. Am. Chem. Soc., 1981, 103, 4017. [all data]

Kiss, Molnar, et al., 1949
Kiss, A.; Molnar, J.; Sandorfy, C., Les spectres d'absorption des derives phenoliques, Bull. Soc. Chim. Fr., 1949, 16, 275-280. [all data]

Notes

Go To: Top, Gas phase thermochemistry data, Gas phase ion energetics data, IR Spectrum, UV/Visible spectrum, References

• Symbols used in this document:
  

  Cp,gas	Constant pressure heat capacity of gas
  IE (evaluated)	Recommended ionization energy
  S°gas	Entropy of gas at standard conditions
  ΔfH°gas	Enthalpy of formation of gas at standard conditions
  ΔrG°	Free energy of reaction at standard conditions
  ΔrH°	Enthalpy of reaction at standard conditions

• Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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