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
  The 3d structure may be viewed using Java or Javascript.
• 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:
  • Phase change data
  • Gas phase ion energetics data
  • Mass spectrum (electron ionization)
  • References
  • Notes
• Other data available:
  • Gas phase thermochemistry data
  • Condensed phase thermochemistry data
  • Reaction thermochemistry data
  • Henry's Law data
  • IR Spectrum
  • UV/Visible spectrum
  • Gas Chromatography
• Data at other public NIST sites:
  • X-ray Photoelectron Spectroscopy Database, version 5.0
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Phase change data

Go To: Top, Gas phase ion energetics data, Mass spectrum (electron ionization), References, Notes

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:
BS - Robert L. Brown and Stephen E. Stein
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
AC - William E. Acree, Jr., James S. Chickos
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DRB - Donald R. Burgess, Jr.
DH - Eugene S. Domalski and Elizabeth D. Hearing

Reduced pressure boiling point

Enthalpy of vaporization

Antoine Equation Parameters

log₁₀(P) = A − (B / (T + C))
    P = vapor pressure (atm)
    T = temperature (K)

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Enthalpy of sublimation

Enthalpy of fusion

Entropy of fusion

Gas phase ion energetics data

Go To: Top, Phase change data, Mass spectrum (electron ionization), 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

Mass spectrum (electron ionization)

Go To: Top, Phase change data, Gas phase ion energetics data, References, Notes

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

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

Spectrum

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Additional Data

References

Go To: Top, Phase change data, Gas phase ion energetics data, Mass spectrum (electron ionization), Notes

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

Aldrich Chemical Company Inc., 1990
Aldrich Chemical Company Inc., Catalog Handbook of Fine Chemicals, Aldrich Chemical Company, Inc., Milwaukee WI, 1990, 1. [all data]

Krupatkin and Rozhentsova, 1971
Krupatkin, I.L.; Rozhentsova, E.P., Some properties of systems with latent liquid immiscibility, Russ. J. Phys. Chem. (Engl. Transl.), 1971, 45, 1700. [all data]

Bret-Dibat and Lichanot, 1989
Bret-Dibat, P.; Lichanot, A., Proprietes thermodynamiques des isomeres de position de benzenes disubstitues en phase condensee, Thermochim. Acta, 1989, 147, 2, 261, https://doi.org/10.1016/0040-6031(89)85181-0 . [all data]

Buckingham and Donaghy, 1982
Buckingham, J.; Donaghy, S.M., Dictionary of Organic Compounds: Fifth Edition, Chapman and Hall, New York, 1982, 1. [all data]

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

Andrews, Lynn, et al., 1926
Andrews, D.H.; Lynn, G.; Johnston, J., The Heat Capacities and Heat of Crystallization of Some Isomeric Aromatic Compounds, J. Am. Chem. Soc., 1926, 48, 1274. [all data]

Verevkin and Kozlova, 2008
Verevkin, Sergey P.; Kozlova, Svetlana A., Di-hydroxybenzenes: Catechol, resorcinol, and hydroquinone, Thermochimica Acta, 2008, 471, 1-2, 33-42, https://doi.org/10.1016/j.tca.2008.02.016 . [all data]

Sabbah and Buluku, 1991, 2
Sabbah, R.; Buluku, E.N.L.E., Thermodynamic study of three isomers of dihydroxybenzene, Can. J. Chem., 1991, 69, 481-488. [all data]

Magnus, 1956
Magnus, A., Die resonanzenergien der parachinone Aui grund der prazisionsmessungsen ihrer verbrennungswarmen durch herrn gerhard wittwer, Z. Phys. Chem. (Neue Folge), 1956, 9, 141-161. [all data]

Cox and Pilcher, 1970
Cox, J.D.; Pilcher, G., Thermochemistry of Organic and Organometallic Compounds, Academic Press, New York, 1970, 1-636. [all data]

Coolidge and Coolidge, 1927
Coolidge, A.S.; Coolidge, M.S., The sublimation pressures of substituted quinones and hydroquinones, J. Am. Chem. Soc., 1927, 49, 100-104. [all data]

Weast and Grasselli, 1989
CRC Handbook of Data on Organic Compounds, 2nd Editon, Weast,R.C and Grasselli, J.G., ed(s)., CRC Press, Inc., Boca Raton, FL, 1989, 1. [all data]

Stephenson and Malanowski, 1987
Stephenson, Richard M.; Malanowski, Stanislaw, Handbook of the Thermodynamics of Organic Compounds, 1987, https://doi.org/10.1007/978-94-009-3173-2 . [all data]

von Terres, Gebert, et al., 1955
von Terres, E.; Gebert, F.; Hulsemann, H.; Petereit, H.; Toepsch, H.; Ruppert, W., Zur Kenntnis der physikalisch-chemischen Grundlagen der Gewinnung und Zerlegung der Phenolfraktionen von Steinkohlenteer und Braunkohlenschwelteer. IV. Mitteilung Die Dampfdrucke von Phenol und Phenolderivaten, Brennst.-Chem., 1955, 36, 272-274. [all data]

Chen, Oja, et al., 2006
Chen, Xu; Oja, Vahur; Chan, W. Geoffrey; Hajaligol, Mohammad R., Vapor Pressure Characterization of Several Phenolics and Polyhydric Compounds by Knudsen Effusion Method, J. Chem. Eng. Data, 2006, 51, 2, 386-391, https://doi.org/10.1021/je050293h . [all data]

Bender, Bieling, et al., 1983
Bender, R.; Bieling, V.; Maurer, G., The vapour pressures of solids: anthracene, hydroquinone, and resorcinol, The Journal of Chemical Thermodynamics, 1983, 15, 6, 585-594, https://doi.org/10.1016/0021-9614(83)90058-7 . [all data]

de Kruif, 1981
de Kruif, C.G., Thermodynamic properties of 1,4-benzoquinone (BQ), 1,4-hydroquinone (HQ), 1,4-naphthoquinone (NQ), 1,4-naphthohydroquinone (NHQ), and the complexes BQ--HQ 1:1, NQ--HQ 1:1, NQ--NHQ 2:1, and NQ--NHQ 1:1, J. Chem. Phys., 1981, 74, 10, 5838, https://doi.org/10.1063/1.440898 . [all data]

Wolf and Weghofer, 1938
Wolf, K.L.; Weghofer, H., Uber sublimationswarmen, Z. Phys. Chem., 1938, 39, 194-208. [all data]

Bret-Dibat and Lichanot, 1989, 2
Bret-Dibat, P.; Lichanot, A., Thermodynamic properties of positional isomers of disubstituted benzene in condensed phase, Thermochim. Acta, 1989, 147(2), 261-271. [all data]

Andrews, Lynn, et al., 1926, 2
Andrews, D.H.; Lynn, G.; Johnston, J., The heat capacities and heat of crystallization of some isomeric aromatic compounds, J. Am. Chem. Soc., 1926, 48, 1274-1287. [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]

Notes

Go To: Top, Phase change data, Gas phase ion energetics data, Mass spectrum (electron ionization), References

• Symbols used in this document:
  

  IE (evaluated)	Recommended ionization energy
  Tboil	Boiling point
  Tfus	Fusion (melting) point
  Ttriple	Triple point temperature
  ΔfusH	Enthalpy of fusion
  ΔfusS	Entropy of fusion
  ΔrG°	Free energy of reaction at standard conditions
  ΔrH°	Enthalpy of reaction at standard conditions
  ΔsubH	Enthalpy of sublimation
  ΔsubH°	Enthalpy of sublimation at standard conditions
  ΔvapH	Enthalpy of vaporization
  ΔvapH°	Enthalpy of vaporization at standard conditions

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