p-Benzoquinone

Formula: C₆H₄O₂
Molecular weight: 108.0948
IUPAC Standard InChI: InChI=1S/C6H4O2/c7-5-1-2-6(8)4-3-5/h1-4H
IUPAC Standard InChIKey: AZQWKYJCGOJGHM-UHFFFAOYSA-N
CAS Registry Number: 106-51-4
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: 2,5-Cyclohexadiene-1,4-dione; p-Quinone; Chinone; Quinone; 1,4-Benzoquinone; 1,4-Cyclohexadienedione; Benzoquinone; Benzo-chinon; Chinon; Cyclohexadienedione; NCI-C55845; 1,4-Benzoquine; 1,4-Cyclohexadiene dioxide; 1,4-Diossibenzene; 1,4-Dioxy-benzol; p-Chinon; Rcra waste number U197; UN 2587; USAF P-220; Steara PBQ; NSC 36324
Permanent link for this species. Use this link for bookmarking this species for future reference.
Information on this page:
Other data available:
Data at other public NIST sites:
- Gas Phase Kinetics Database
- X-ray Photoelectron Spectroscopy Database, version 5.0
Options:
- Switch to calorie-based units

Data at NIST subscription sites:

NIST / TRC Web Thermo Tables, professional edition (thermophysical and thermochemical data)

NIST subscription sites provide data under the NIST Standard Reference Data Program, but require an annual fee to access. The purpose of the fee is to recover costs associated with the development of data collections included in such sites. Your institution may already be a subscriber. Follow the links above to find out more about the data in these sites and their terms of usage.

Gas phase thermochemistry data

Go To: Top, Condensed phase thermochemistry data, Gas phase ion energetics data, References, Notes

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

Quantity	Value	Units	Method	Reference	Comment
Δ_cH°_gas	-2810. ± 4.	kJ/mol	Ccb	Wassermann, 1935	Corresponding Δ_fHº_gas = -120. kJ/mol (simple calculation by NIST; no Washburn corrections); ALS

Constant pressure heat capacity of gas

C_p,gas (J/mol*K)	Temperature (K)	Reference	Comment
37.66	50.	Becker E.D., 1965	GT
47.65	100.
61.20	150.
76.51	200.
99.66	273.15
107.39	298.15
107.95	300.
136.31	400.
159.73	500.
178.51	600.
193.57	700.
205.80	800.
215.86	900.
224.22	1000.
231.23	1100.
237.15	1200.
242.19	1300.
246.49	1400.
250.18	1500.

Condensed phase thermochemistry data

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

Data compiled as indicated in comments:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DH - Eugene S. Domalski and Elizabeth D. Hearing

Quantity	Value	Units	Method	Reference	Comment
Δ_fH°_solid	-186.8 ± 0.71	kJ/mol	Ccb	Pilcher and Sutton, 1956	ALS
Δ_fH°_solid	-184.5 ± 0.63	kJ/mol	Ccb	Parks, Manchester, et al., 1954	ALS
Δ_fH°_solid	-184.5	kJ/mol	Ccb	Schreiner, 1925	ALS
Quantity	Value	Units	Method	Reference	Comment
Δ_cH°_solid	-2725.80	kJ/mol	Ccb	Magnus, 1956	Corresponding Δ_fHº_solid = -206.92 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS
Δ_cH°_solid	-2745.9 ± 0.42	kJ/mol	Ccb	Pilcher and Sutton, 1956	Corresponding Δ_fHº_solid = -186.8 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS
Δ_cH°_solid	-2748.2	kJ/mol	Ccb	Parks, Manchester, et al., 1954	Corresponding Δ_fHº_solid = -184.5 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS
Δ_cH°_solid	-2748.3	kJ/mol	Ccb	Schreiner, 1925	Corresponding Δ_fHº_solid = -184.5 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS
Δ_cH°_solid	-2753.	kJ/mol	Ccb	Swietoslawski and Starczedska, 1925	Corresponding Δ_fHº_solid = -179. kJ/mol (simple calculation by NIST; no Washburn corrections); ALS

Constant pressure heat capacity of solid

C_p,solid (J/mol*K)	Temperature (K)	Reference	Comment
126.4	298.15	Ueberreiter and Orthmann, 1950	T = 293 to 368 K. Equation only.; DH
132.2	298.	Andrews, Lynn, et al., 1926	T = 22 to 160°C.; DH
129.7	291.2	Lange, 1924	T = 22 to 291 K. Value is unsmoothed experimental datum.; DH

Gas phase ion energetics data

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, References, Notes

Data evaluated as indicated in comments:
HL - Edward P. Hunter and Sharon G. Lias
L - Sharon G. Lias

Data compiled as indicated in comments:
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
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
B - John E. Bartmess

Quantity	Value	Units	Method	Reference	Comment
IE (evaluated)	10.0 ± 0.1	eV	N/A	N/A	L
Quantity	Value	Units	Method	Reference	Comment
Proton affinity (review)	799.1	kJ/mol	N/A	Hunter and Lias, 1998	HL
Quantity	Value	Units	Method	Reference	Comment
Gas basicity	769.3	kJ/mol	N/A	Hunter and Lias, 1998	HL

Electron affinity determinations

EA (eV)	Method	Reference	Comment
1.850 ± 0.010	LPES	Fu, Yang, et al., 2011	Triplet state of neutral 2.32 eV up; B
1.8600 ± 0.0050	LPES	Schiedt and Weinkauf, 1999	Neutral T1 state is 2.3 eV up: Siegert, Vogeler, et al., 20112; B
1.91 ± 0.10	TDEq	Heinis, Chowdhury, et al., 1988	ΔGea(423 K) = -42.4 kcal/mol; ΔSea = -4.0 eu.; B
1.930 ± 0.048	IMRE	Fukuda and McIver, 1985	ΔGea(355 K) = -43.1 kcal/mol; ΔSea =-4.0, est. from data in Heinis, Chowdhury, et al., 1988; B
1.990 ± 0.048	LPD	Marks, Comita, et al., 1985	B
1.89 ± 0.30	NBIE	Cooper, Naff, et al., 1975	B
1.370 ± 0.078	SI	Farragher and Page, 1966	The Magnetron method, lacking mass analysis, is not considered reliable.; B

Ionization energy determinations

IE (eV)	Method	Reference	Comment
10.11	PE	Lauer, Schafer, et al., 1975	LLK
10.01	PE	Kobayashi, 1975	LLK
9.96 ± 0.01	PI	Kotov and Potapov, 1972	LLK
9.96 ± 0.01	PI	Potapov and Sorokin, 1971	LLK
9.95	PE	Dewar and Worley, 1969	RDSH
9.7	PI	Terenin, 1961	RDSH
9.67 ± 0.02	PI	Vilesov and Terenin, 1957	RDSH
10.1	PE	Bock, Mohmand, et al., 1983	Vertical value; LBLHLM
9.99 ± 0.05	PE	Dougherty and McGlynn, 1977	Vertical value; LLK
10.03	PE	Cowan, Gleiter, et al., 1971	Vertical value; LLK

Appearance energy determinations

Ion	AE (eV)	Other Products	Method	Reference	Comment
C₄H₂O₂⁺	11.2 ± 0.05	C₂H₂	PI	Potapov and Sorokin, 1971	LLK
C₅H₄O⁺	11.10 ± 0.05	CO	PI	Potapov and Sorokin, 1971	LLK

References

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Gas phase ion energetics data, Notes

Wassermann, 1935
Wassermann, A., The mechanism of additions to double bonds. Part I. Thermochemistry and kinetics of a diene synthesis, J. Chem. Soc., 1935, 828-838. [all data]

Becker E.D., 1965
Becker E.D., Molecular vibrations of quinones. VI. A vibrational assignment for p-benzoquinone and six isotopic derivatives. Thermodynamic functions of p-benzoquinone, J. Chem. Phys., 1965, 42, 942-949. [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]

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

Swietoslawski and Starczedska, 1925
Swietoslawski, W.; Starczedska, H., Correction des donnees thermochimiques de M.A. Valeur, J. Chem. Phys., 1925, 22, 399-401. [all data]

Ueberreiter and Orthmann, 1950
Ueberreiter, K.; Orthmann, H.-J., Specifische Wärme, spezifisches Volumen, Temperatur- und Wärme-leittähigkeit einiger disubstituierter Benzole und polycyclischer Systeme, Z. Natursforsch. 5a, 1950, 101-108. [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, 1274-1287. [all data]

Lange, 1924
Lange, F., Untersuchungen über die spezifische Wärme bei tiefen Temperaturen, Z. Phys. Chem., 1924, 110, 343-362. [all data]

Hunter and Lias, 1998
Hunter, E.P.; Lias, S.G., Evaluated Gas Phase Basicities and Proton Affinities of Molecules: An Update, J. Phys. Chem. Ref. Data, 1998, 27, 3, 413-656, https://doi.org/10.1063/1.556018 . [all data]

Fu, Yang, et al., 2011
Fu, Q.A.; Yang, J.L.; Wang, X.B., On the Electronic Structures and Electron Affinities of the m-Benzoquinone (BQ) Diradical and the o-, p-BQ Molecules: A Synergetic Photoelectron Spectroscopic and Theoretical Study, J. Phys. Chem. A, 2011, 115, 15, 3201-3207, https://doi.org/10.1021/jp1120542 . [all data]

Schiedt and Weinkauf, 1999
Schiedt, J.; Weinkauf, R., Resonant Photodetachment via Shape and Feshbach Resonances: p-Benzoquinone Anions as a Model System, J. Chem. Phys., 1999, 110, 1, 304, https://doi.org/10.1063/1.478066 . [all data]

Siegert, Vogeler, et al., 2011
Siegert, S.; Vogeler, F.; Marian, C.M.; Weinkauf, R., Throwing light on dark states of alpha-oligothiophenes of chain lengths 2 to 6: radical anion photoelectron spectroscopy and excited-state theory, Phys. Chem. Chem. Phys., 2011, 13, 21, 10350-10363, https://doi.org/10.1039/c0cp02712j . [all data]

Heinis, Chowdhury, et al., 1988
Heinis, T.; Chowdhury, S.; Scott, S.L.; Kebarle, P., Electron Affinities of Benzo-, Naphtho-, and Anthraquinones Determined from Gas-Phase Equilibria Measurements, J. Am. Chem. Soc., 1988, 110, 2, 400, https://doi.org/10.1021/ja00210a015 . [all data]

Fukuda and McIver, 1985
Fukuda, E.K.; McIver, R.T., Jr., Relative electron affinities of substituted benzophenones, nitrobenzenes, and quinones. [Anchored to EA(SO₂) from 74CEL/BEN], J. Am. Chem. Soc., 1985, 107, 2291. [all data]

Marks, Comita, et al., 1985
Marks, J.; Comita, P.B.; Brauman, J.I., Threshold resonances in electron photodetachment spectra. Structural evidence for dipole-supported states, J. Am. Chem. Soc., 1985, 107, 3718. [all data]

Cooper, Naff, et al., 1975
Cooper, C.D.; Naff, W.T.; Compton, R.N., Negative ion properties of p-benzoquinone: Electron affinity and compound states, J. Chem. Phys., 1975, 63, 2752. [all data]

Farragher and Page, 1966
Farragher, A.L.; Page, F.M., Experimental Determination of Electron Affinities. Part 9. - Benzoquinone, Chloranil and Related Compounds, Trans. Farad. Soc., 1966, 62, 3072, https://doi.org/10.1039/tf9666203072 . [all data]

Lauer, Schafer, et al., 1975
Lauer, G.; Schafer, W.; Schweig, A., Assignment of the four lowest ionized states of p-benzoquinone and the question of "lone pair" splitting in this system, Chem. Phys. Lett., 1975, 33, 312. [all data]

Kobayashi, 1975
Kobayashi, T., Photoelectron spectra of p-benzoquinones, J. Electron. Spectrosc. Relat. Phenom., 1975, 7, 349. [all data]

Kotov and Potapov, 1972
Kotov, B.V.; Potapov, V.K., Ionization potentials of strong organic electron acceptors, Khim. Vys. Energ., 1972, 6, 375. [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]

Dewar and Worley, 1969
Dewar, M.J.S.; Worley, S.D., Photoelectron spectra of molecules. I. Ionization potentials of some organic molecules and their interpretation, J. Chem. Phys., 1969, 50, 654. [all data]

Terenin, 1961
Terenin, A., Charge transfer in organic solids, induced by light, Proc. Chem. Soc., London, 1961, 321. [all data]

Vilesov and Terenin, 1957
Vilesov, F.I.; Terenin, A.N., The photoionization of the vapors of certain organic compounds, Dokl. Akad. Nauk SSSR, 1957, 115, 744, In original 539. [all data]

Bock, Mohmand, et al., 1983
Bock, H.; Mohmand, S.; Hirabayashi, T.; Maier, G.; Reisenauer, H.P., Photoelektronen-spektroskopischer nachweis und matrix-isolierung von thio-para-benzochinonen, Chem. Ber., 1983, 116, 273. [all data]

Dougherty and McGlynn, 1977
Dougherty, D.; McGlynn, S.P., Photoelectron spectroscopy of carbonyls. 1,4-Benzoquinones, J. Am. Chem. Soc., 1977, 99, 3234. [all data]

Cowan, Gleiter, et al., 1971
Cowan, D.O.; Gleiter, R.; Hashmall, J.A.; Heilbronner, E.; Hornung, V., Interaction between the orbitals of lone pair electrons in dicarbonyl compounds, Angew. Chem. Int. Ed. Engl., 1971, 10, 401. [all data]

Notes

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Gas phase ion energetics data, References

Symbols used in this document:

AE	Appearance energy
C_p,gas	Constant pressure heat capacity of gas
C_p,solid	Constant pressure heat capacity of solid
EA	Electron affinity
IE (evaluated)	Recommended ionization energy
Δ_cH°_gas	Enthalpy of combustion of gas at standard conditions
Δ_cH°_solid	Enthalpy of combustion of solid at standard conditions
Δ_fH°_solid	Enthalpy of formation of solid at standard conditions

Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
The National Institute of Standards and Technology (NIST) uses its best efforts to deliver a high quality copy of the Database and to verify that the data contained therein have been selected on the basis of sound scientific judgment. However, NIST makes no warranties to that effect, and NIST shall not be liable for any damage that may result from errors or omissions in the Database.
Customer support for NIST Standard Reference Data products.