Benzene, pentafluoro-

• Formula: C₆HF₅
• Molecular weight: 168.0642
• IUPAC Standard InChI:
  

  InChI=1S/C6HF5/c7-2-1-3(8)5(10)6(11)4(2)9/h1H Download the identifier in a file.

• IUPAC Standard InChIKey: WACNXHCZHTVBJM-UHFFFAOYSA-N
• CAS Registry Number: 363-72-4
• 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: Pentafluorobenzene; 1,2,3,4,5-Pentafluorobenzene
• Permanent link for this species. Use this link for bookmarking this species for future reference.
• Information on this page:
  • Gas phase thermochemistry data
  • Condensed phase thermochemistry data
  • Reaction thermochemistry data
  • References
  • Notes
• Other data available:
  • Phase change data
  • Gas phase ion energetics data
  • Ion clustering data
  • IR Spectrum
  • Mass spectrum (electron ionization)
  • UV/Visible spectrum
  • Gas Chromatography
• Data at other public NIST sites:
  • Gas Phase Kinetics Database
  • X-ray Photoelectron Spectroscopy Database, version 4.1
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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 by: Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein

Quantity	Value	Units	Method	Reference	Comment
fH°gas	-806.0 ± 1.4	kJ/mol	Ccr	Cox, Gundry, et al., 1969

Condensed 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
DH - Eugene S. Domalski and Elizabeth D. Hearing

Quantity	Value	Units	Method	Reference	Comment
fH°liquid	-842.2 ± 1.4	kJ/mol	Ccr	Cox, Gundry, et al., 1969	ALS
Quantity	Value	Units	Method	Reference	Comment
cH°liquid	-2557.0 ± 1.4	kJ/mol	Ccr	Cox, Gundry, et al., 1969	ALS
Quantity	Value	Units	Method	Reference	Comment
S°liquid	279.49	J/mol*K	N/A	Paukov and Lavrent'eva, 1969	DH
S°liquid	275.9	J/mol*K	N/A	Counsell, Hales, et al., 1968	DH

Constant pressure heat capacity of liquid

Reaction 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:
B - John E. Bartmess
M - Michael M. Meot-Ner (Mautner) and Sharon G. Lias
RCD - Robert C. Dunbar

Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. A general reaction search form is also available. Future versions of this site may rely on reaction search pages in place of the enumerated reaction displays seen below.

Individual Reactions

 +  = (  )

By formula: F^- + C₆HF₅ = (F^-  C₆HF₅)

Quantity	Value	Units	Method	Reference	Comment
rH°	122. ± 8.4	kJ/mol	IMRE	Dillow and Kebarle, 1988	gas phase; Anchored to C6F6..F- in Hiraoka, Mizuse, et al., 1987; B,M
Quantity	Value	Units	Method	Reference	Comment
rS°	84.1	J/mol*K	N/A	Dillow and Kebarle, 1988	gas phase; switching reaction,Thermochemical ladder(F-)C6F6, Entropy change calculated or estimated; Hiraoka, Mizuse, et al., 1987; M
Quantity	Value	Units	Method	Reference	Comment
rG°	86.6 ± 8.4	kJ/mol	IMRE	Dillow and Kebarle, 1988	gas phase; Anchored to C6F6..F- in Hiraoka, Mizuse, et al., 1987; B

Free energy of reaction

rG° (kJ/mol)	T (K)	Method	Reference	Comment
86.6	423.	PHPMS	Dillow and Kebarle, 1988	gas phase; switching reaction,Thermochemical ladder(F-)C6F6, Entropy change calculated or estimated; Hiraoka, Mizuse, et al., 1987; M

C₆F₅^- +  =

By formula: C₆F₅^- + H⁺ = C₆HF₅

Quantity	Value	Units	Method	Reference	Comment
rH°	1492. ± 8.8	kJ/mol	G+TS	Buker, Nibbering, et al., 1997	gas phase; B
rH°	<1559.6 ± 1.3	kJ/mol	G+TS	Herd, Adams, et al., 1989	gas phase; More acidic than HF, less than HCl; B
rH°	1539. ± 21.	kJ/mol	D-EA	Compton and Reinhardt, 1982	gas phase; From perfluorobenzene; B
Quantity	Value	Units	Method	Reference	Comment
rG°	1460. ± 8.4	kJ/mol	IMRE	Buker, Nibbering, et al., 1997	gas phase; B
rG°	<1527.2	kJ/mol	IMRB	Herd, Adams, et al., 1989	gas phase; More acidic than HF, less than HCl; B
rG°	1507. ± 21.	kJ/mol	H-TS	Compton and Reinhardt, 1982	gas phase; From perfluorobenzene; B

C₆H₆⁺ +  = (C₆H₆⁺  )

By formula: C₆H₆⁺ + C₆HF₅ = (C₆H₆⁺  C₆HF₅)

Bond type: Charge transfer bond (positive ion)

Quantity	Value	Units	Method	Reference	Comment
rH°	46.9	kJ/mol	PHPMS	Meot-Ner (Mautner), Hamlet, et al., 1978	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
rS°	110.	J/mol*K	N/A	Meot-Ner (Mautner), Hamlet, et al., 1978	gas phase; Entropy change calculated or estimated; M

Free energy of reaction

rG° (kJ/mol)	T (K)	Method	Reference	Comment
13.	300.	PHPMS	Meot-Ner (Mautner), Hamlet, et al., 1978	gas phase; Entropy change calculated or estimated; M

 +  = (  )

By formula: Cr⁺ + C₆HF₅ = (Cr⁺  C₆HF₅)

Quantity	Value	Units	Method	Reference	Comment
rH°	99.2	kJ/mol	RAK	Ryzhov, 1999	RCD

References

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

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

Cox, Gundry, et al., 1969
Cox, J.D.; Gundry, H.A.; Harrop, D.; Head, A.J., Thermodynamic properties of fluorine compounds. 9. Enthalpies of formation of some compounds containing the pentafluorophenyl group, J. Chem. Thermodyn., 1969, 1, 77-87. [all data]

Paukov and Lavrent'eva, 1969
Paukov, I.E.; Lavrent'eva, M.N., Thermodynamic properties of pentafluorobenzene over the range 12-300K, Zhur. Fiz. Khim., 1969, 43, 2938-2941. [all data]

Counsell, Hales, et al., 1968
Counsell, J.F.; Hales, J.L.; Martin, J.F., Thermodynamic properties of fluorine compounds. Part VI. The heat capacity and entropy of pentafluorobenzene, J. Chem. Soc. A, 1968, 2042-2044. [all data]

Dillow and Kebarle, 1988
Dillow, G.W.; Kebarle, P., Fluoride Affinities of Perfluorobenzenes C₆F₅X. Meisenheimer Complexes in the Gas Phase and Solution, J. Am. Chem. Soc., 1988, 110, 15, 4877, https://doi.org/10.1021/ja00223a001 . [all data]

Hiraoka, Mizuse, et al., 1987
Hiraoka, K.; Mizuse, S.; Yamabe, S., A Determination of the Stability and Structure of F^-(C₆H₆) and F^-(C₆F₆) Clusters, J. Chem. Phys., 1987, 86, 7, 4102, https://doi.org/10.1063/1.451920 . [all data]

Buker, Nibbering, et al., 1997
Buker, H.H.; Nibbering, N.M.M.; Espinosa, D.; Mongin, F.; Schlosser, M., Additivity of substituent effects in the fluoroarene series: Equilibrium acidity in the gas phase and deprotonation rates in ethereal solution, Tetrahed. Lett., 1997, 38, 49, 8519-8522, https://doi.org/10.1016/S0040-4039(97)10303-3 . [all data]

Herd, Adams, et al., 1989
Herd, C.R.; Adams, N.G.; Smith, D., FALP Studies of Electron Attachment Reactions of C6F5Cl, C6F5Br, and C6F5I, Int. J. Mass Spectrom. Ion Proc., 1989, 87, 3, 331, https://doi.org/10.1016/0168-1176(89)80032-1 . [all data]

Compton and Reinhardt, 1982
Compton, R.N.; Reinhardt, P.W., Collisonal ionization between fast alkali atoms and hexafluorobenzene, Chem. Phys. Lett., 1982, 91, 268. [all data]

Meot-Ner (Mautner), Hamlet, et al., 1978
Meot-Ner (Mautner), M.; Hamlet, P.; Hunter, E.P.; Field, F.H., Bonding Energies in Association Ions of Aromatic Molecules. Correlations with Ionization Energies, J. Am. Chem. Soc., 1978, 100, 17, 5466, https://doi.org/10.1021/ja00485a034 . [all data]

Ryzhov, 1999
Ryzhov, V., Binding Energies of Chromium Cations with Fluorobenzenes from Radiative Association Kinetics, Int. J. Mass Spectrom., 1999, 185/186/187, 913. [all data]

Notes

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

• Symbols used in this document:
  

  Cp,liquid	Constant pressure heat capacity of liquid
  S°liquid	Entropy of liquid at standard conditions
  T	Temperature
  cH°liquid	Enthalpy of combustion of liquid at standard conditions
  fH°gas	Enthalpy of formation of gas at standard conditions
  fH°liquid	Enthalpy of formation of liquid at standard conditions
  rG°	Free energy of reaction at standard conditions
  rH°	Enthalpy of reaction at standard conditions
  rS°	Entropy of reaction at standard conditions

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