Benzene, 1,4-difluoro-

• Formula: C₆H₄F₂
• Molecular weight: 114.0928
• IUPAC Standard InChI: InChI=1S/C6H4F2/c7-5-1-2-6(8)4-3-5/h1-4H Copy

  
• IUPAC Standard InChIKey: QUGUFLJIAFISSW-UHFFFAOYSA-N Copy
• CAS Registry Number: 540-36-3
• 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: Benzene, p-difluoro-; p-Difluorobenzene; 1,4-Difluorobenzene; para-Difluorobenzene
• Permanent link for this species. Use this link for bookmarking this species for future reference.
• Information on this page:
  • Gas phase ion energetics data
  • Mass spectrum (electron ionization)
  • Gas Chromatography
  • References
  • Notes
• Other data available:
  • Gas phase thermochemistry data
  • Condensed phase thermochemistry data
  • Phase change data
  • Reaction thermochemistry data
  • Henry's Law data
  • Ion clustering data
  • IR Spectrum
• Data at other public NIST sites:
  • Gas Phase Kinetics Database
• Options:
  • Switch to SI 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 ion energetics data

Go To: Top, Mass spectrum (electron ionization), Gas Chromatography, 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:
HL - Edward P. Hunter and Sharon G. Lias
L - Sharon G. Lias

Data compiled as indicated in comments:
B - John E. Bartmess
LL - Sharon G. Lias and Joel F. Liebman
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron

Ionization energy determinations

Appearance energy determinations

De-protonation reactions

C₆H₃F₂^- +  =

By formula: C₆H₃F₂^- + H⁺ = C₆H₄F₂

Mass spectrum (electron ionization)

Go To: Top, Gas phase ion energetics data, Gas Chromatography, 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

Notice: This spectrum may be better viewed with a Javascript and HTML 5 enabled browser.

For Zoom

1.) Enter the desired X axis range (e.g., 100, 200)

2.) Check here for automatic Y scaling

3.) Press here to zoom

Additional Data

Gas Chromatography

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

Van Den Dool and Kratz RI, non-polar column, temperature ramp

View large format table.

Normal alkane RI, non-polar column, temperature ramp

View large format table.

References

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

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

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]

Rieger, Reiser, et al., 1992
Rieger, D.; Reiser, G.; Muller-Dethlefs, K.; Schlag, E.W., Zero kinetic energy photoelectron spectroscopy of p-difluorobenzene, J. Phys. Chem., 1992, 96, 12. [all data]

Reiger, 1990
Reiger, D., [Title unavailable], Diplomarbeit, Techn. Universitat Munich, 1990. [all data]

Bieri, Asbrink, et al., 1981
Bieri, G.; Asbrink, L.; Von Niessen, W., 30.4 nm He(II) photoelectron spectra of organic molecules. Part IV. Fluoro-compounds (C,H,F), J. Electron Spectrosc. Relat. Phenom., 1981, 23, 281. [all data]

Lias and Ausloos, 1978
Lias, S.G.; Ausloos, P.J., eIonization energies of organic compounds by equilibrium measurements, J. Am. Chem. Soc., 1978, 100, 6027. [all data]

Gilbert and Sandorfy, 1974
Gilbert, R.; Sandorfy, C., Rydberg transitions in the ultraviolet spectra of difluorobenzenes, Chem. Phys. Lett., 1974, 27, 457. [all data]

Clark and Frost, 1967
Clark, I.D.; Frost, D.C., A study of the energy levels in benzene and some fluorobenzenes by photoelectron spectroscopy, J. Am. Chem. Soc., 1967, 89, 244. [all data]

Bralsford, Harris, et al., 1960
Bralsford, R.; Harris, P.V.; Price, W.C., The effect of fluorine on the electronic spectra and ionization potentials of molecules, Proc. Roy. Soc. (London), 1960, A258, 459. [all data]

Sell, Mintz, et al., 1978
Sell, J.A.; Mintz, D.M.; Kupperman, A., Photoelectron angular distributions of carbon-carbon π electrons in ethylene, benzene, and their fluorinated derivatives, Chem. Phys. Lett., 1978, 58, 601. [all data]

Streets and Ceasar, 1973
Streets, D.G.; Ceasar, G.P., Inductive mesomeric effects on the π orbitals of halobenzenes, Mol. Phys., 1973, 26, 1037. [all data]

Klessinger, 1972
Klessinger, M., Ionization potentials of substituted benzenes, Angew. Chem. Int. Ed. Engl., 1972, 11, 525. [all data]

Momigny and Wirtz-Cordier, 1962
Momigny, J.; Wirtz-Cordier, A.M., Les effets de l'impact electronique sur des derives dihalogenes du benzene, Ann. Soc. Sci. Bruxelles, 1962, 76, 164. [all data]

Majer and Patrick, 1962
Majer, J.R.; Patrick, C.R., Electron impact on some halogenated aromatic compounds, J. Chem. Soc. Faraday Trans., 1962, 58, 17. [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]

Briscese and Riveros, 1975
Briscese, S.M.J.; Riveros, J.M., Gas phase nucleophilic reactions of aromatic systems, J. Am. Chem. Soc., 1975, 97, 230. [all data]

Peng, Ding, et al., 1988
Peng, C.T.; Ding, S.F.; Hua, R.L.; Yang, Z.C., Prediction of Retention Indexes I. Structure-Retention Index Relationship on Apolar Columns, J. Chromatogr., 1988, 436, 137-172, https://doi.org/10.1016/S0021-9673(00)94575-8 . [all data]

Zenkevich, 2005
Zenkevich, I.G., Experimentally measured retention indices., 2005. [all data]

Notes

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

• Symbols used in this document:
  

  AE	Appearance energy
  IE (evaluated)	Recommended ionization energy
  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
• 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.