Benzene, 1,4-difluoro-

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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
Δfgas-73.30 ± 0.25kcal/molCcrGood, Lacina, et al., 1962Corrected for CODATA value of ΔfH

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
Δfliquid-81.81 ± 0.25kcal/molCcrGood, Lacina, et al., 1962Corrected for CODATA value of ΔfH; ALS
Quantity Value Units Method Reference Comment
Δcliquid-704.68 ± 0.13kcal/molCcrGood, Lacina, et al., 1962Corrected for CODATA value of ΔfH; ALS
Δcliquid-706.1kcal/molCcbSwarts, 1919Not corrected for CODATA value of ΔfH; ALS

Constant pressure heat capacity of liquid

Cp,liquid (cal/mol*K) Temperature (K) Reference Comment
38.03298.15Lichanot, 1991T = 186 to 324 K. Cp(liq) = 155.192 + 0.158T(°C) J/mol*K (-35 to 51°C). Cp value calculated from equation.; DH
37.64298.15Good, Lacina, et al., 1962DH

Phase change 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:
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
DH - Eugene S. Domalski and Elizabeth D. Hearing

Quantity Value Units Method Reference Comment
Tboil360. to 361.KN/APCR Inc., 1990BS
Tboil362.2KN/AWeast and Grasselli, 1989BS
Tboil362.KN/AMajer and Svoboda, 1985 
Tboil362.KN/ABergmann, Berkovic, et al., 1956Uncertainty assigned by TRC = 3. K; TRC
Quantity Value Units Method Reference Comment
Tfus249.6KN/AGoates, Ott, et al., 1976Uncertainty assigned by TRC = 0.08 K; TRC
Quantity Value Units Method Reference Comment
Δvap8.513kcal/molN/AMajer and Svoboda, 1985 
Δvap8.56kcal/molN/AOsborn and Scott, 1980Based on data from 300. to 400. K. See also Basarová and Svoboda, 1991.; AC
Δvap8.528kcal/molVFindlay, 1969ALS
Δvap8.51 ± 0.05kcal/molVGood, Lacina, et al., 1962Corrected for CODATA value of ΔfH; ALS

Enthalpy of vaporization

ΔvapH (kcal/mol) Temperature (K) Reference Comment
7.593362.Majer and Svoboda, 1985 

Temperature of phase transition

Ttrs (K) Initial Phase Final Phase Reference Comment
249.45crystaline, IliquidLichanot, 1991DH

Enthalpy of phase transition

ΔHtrs (kcal/mol) Temperature (K) Initial Phase Final Phase Reference Comment
0.00198.crystaline, IIcrystaline, ILichanot, 1991Allotropic transformation.; DH

In addition to the Thermodynamics Research Center (TRC) data available from this site, much more physical and chemical property data is available from the following TRC products:


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

C6H3F2- + Hydrogen cation = Benzene, 1,4-difluoro-

By formula: C6H3F2- + H+ = C6H4F2

Quantity Value Units Method Reference Comment
Δr380.2 ± 2.1kcal/molG+TSBuker, Nibbering, et al., 1997gas phase; B
Δr379.8 ± 3.1kcal/molG+TSBriscese and Riveros, 1975gas phase; < MeOH, <= EtOH; value altered from reference due to change in acidity scale; B
Quantity Value Units Method Reference Comment
Δr372.1 ± 2.0kcal/molIMREBuker, Nibbering, et al., 1997gas phase; B
Δr371.7 ± 3.0kcal/molIMRBBriscese and Riveros, 1975gas phase; < MeOH, <= EtOH; value altered from reference due to change in acidity scale; B

NH4+ + Benzene, 1,4-difluoro- = (NH4+ • Benzene, 1,4-difluoro-)

By formula: H4N+ + C6H4F2 = (H4N+ • C6H4F2)

Quantity Value Units Method Reference Comment
Δr13.kcal/molPHPMSDeakyne and Meot-Ner (Mautner), 1985gas phase; Entropy change calculated or estimated; M
Quantity Value Units Method Reference Comment
Δr20.cal/mol*KN/ADeakyne and Meot-Ner (Mautner), 1985gas phase; Entropy change calculated or estimated; M

Free energy of reaction

ΔrG° (kcal/mol) T (K) Method Reference Comment
5.1395.PHPMSDeakyne and Meot-Ner (Mautner), 1985gas phase; Entropy change calculated or estimated; M

Chlorine anion + Benzene, 1,4-difluoro- = (Chlorine anion • Benzene, 1,4-difluoro-)

By formula: Cl- + C6H4F2 = (Cl- • C6H4F2)

Quantity Value Units Method Reference Comment
Δr13.8 ± 2.0kcal/molIMRELarson and McMahon, 1984gas phase; B,M
Quantity Value Units Method Reference Comment
Δr21.6cal/mol*KN/ALarson and McMahon, 1984gas phase; switching reaction(Cl-)ClCOOCH3, Entropy change calculated or estimated; Larson and McMahon, 1984, 2; M
Quantity Value Units Method Reference Comment
Δr7.3 ± 2.0kcal/molIMRELarson and McMahon, 1984gas phase; B,M

C6H6+ + Benzene, 1,4-difluoro- = (C6H6+ • Benzene, 1,4-difluoro-)

By formula: C6H6+ + C6H4F2 = (C6H6+ • C6H4F2)

Bond type: Charge transfer bond (positive ion)

Quantity Value Units Method Reference Comment
Δr11.3kcal/molMPIErnstberger, Krause, et al., 1990gas phase; M

C6H4F2+ + Benzene, 1,4-difluoro- = (C6H4F2+ • Benzene, 1,4-difluoro-)

By formula: C6H4F2+ + C6H4F2 = (C6H4F2+ • C6H4F2)

Bond type: Charge transfer bond (positive ion)

Quantity Value Units Method Reference Comment
Δr8.8kcal/molMPIErnstberger, Krause, et al., 1990gas phase; M

Chromium ion (1+) + Benzene, 1,4-difluoro- = (Chromium ion (1+) • Benzene, 1,4-difluoro-)

By formula: Cr+ + C6H4F2 = (Cr+ • C6H4F2)

Quantity Value Units Method Reference Comment
Δr29.0kcal/molRAKRyzhov, 1999RCD

Gas phase ion energetics 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 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

Quantity Value Units Method Reference Comment
IE (evaluated)9.1589 ± 0.0005eVN/AN/AL
Quantity Value Units Method Reference Comment
Proton affinity (review)171.8kcal/molN/AHunter and Lias, 1998HL
Quantity Value Units Method Reference Comment
Gas basicity165.6kcal/molN/AHunter and Lias, 1998HL

Ionization energy determinations

IE (eV) Method Reference Comment
9.1590 ± 0.0004TERieger, Reiser, et al., 1992LL
9.1588 ± 0.0002TEReiger, 1990LL
9.14PEBieri, Asbrink, et al., 1981LLK
9.137 ± 0.004EQLias and Ausloos, 1978LLK
9.18SGilbert and Sandorfy, 1974LLK
9.15 ± 0.06PEClark and Frost, 1967RDSH
9.15PIBralsford, Harris, et al., 1960RDSH
9.4PEBieri, Asbrink, et al., 1981Vertical value; LLK
9.29PESell, Mintz, et al., 1978Vertical value; LLK
9.15PEStreets and Ceasar, 1973Vertical value; LLK
9.4 ± 0.03PEKlessinger, 1972Vertical value; LLK

Appearance energy determinations

Ion AE (eV) Other Products MethodReferenceComment
C4H2F2+15.27C2H2EIMomigny and Wirtz-Cordier, 1962RDSH
C6H4F+15.5 ± 0.1FEIMajer and Patrick, 1962RDSH

De-protonation reactions

C6H3F2- + Hydrogen cation = Benzene, 1,4-difluoro-

By formula: C6H3F2- + H+ = C6H4F2

Quantity Value Units Method Reference Comment
Δr380.2 ± 2.1kcal/molG+TSBuker, Nibbering, et al., 1997gas phase; B
Δr379.8 ± 3.1kcal/molG+TSBriscese and Riveros, 1975gas phase; < MeOH, <= EtOH; value altered from reference due to change in acidity scale; B
Quantity Value Units Method Reference Comment
Δr372.1 ± 2.0kcal/molIMREBuker, Nibbering, et al., 1997gas phase; B
Δr371.7 ± 3.0kcal/molIMRBBriscese and Riveros, 1975gas phase; < MeOH, <= EtOH; value altered from reference due to change in acidity scale; B

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

Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. Searches may be limited to ion clustering reactions. A general reaction search form is also available.

Clustering reactions

C6H4F2+ + Benzene, 1,4-difluoro- = (C6H4F2+ • Benzene, 1,4-difluoro-)

By formula: C6H4F2+ + C6H4F2 = (C6H4F2+ • C6H4F2)

Bond type: Charge transfer bond (positive ion)

Quantity Value Units Method Reference Comment
Δr8.8kcal/molMPIErnstberger, Krause, et al., 1990gas phase; M

C6H6+ + Benzene, 1,4-difluoro- = (C6H6+ • Benzene, 1,4-difluoro-)

By formula: C6H6+ + C6H4F2 = (C6H6+ • C6H4F2)

Bond type: Charge transfer bond (positive ion)

Quantity Value Units Method Reference Comment
Δr11.3kcal/molMPIErnstberger, Krause, et al., 1990gas phase; M

Chlorine anion + Benzene, 1,4-difluoro- = (Chlorine anion • Benzene, 1,4-difluoro-)

By formula: Cl- + C6H4F2 = (Cl- • C6H4F2)

Quantity Value Units Method Reference Comment
Δr13.8 ± 2.0kcal/molIMRELarson and McMahon, 1984gas phase; B,M
Quantity Value Units Method Reference Comment
Δr21.6cal/mol*KN/ALarson and McMahon, 1984gas phase; switching reaction(Cl-)ClCOOCH3, Entropy change calculated or estimated; Larson and McMahon, 1984, 2; M
Quantity Value Units Method Reference Comment
Δr7.3 ± 2.0kcal/molIMRELarson and McMahon, 1984gas phase; B,M

Chromium ion (1+) + Benzene, 1,4-difluoro- = (Chromium ion (1+) • Benzene, 1,4-difluoro-)

By formula: Cr+ + C6H4F2 = (Cr+ • C6H4F2)

Quantity Value Units Method Reference Comment
Δr29.0kcal/molRAKRyzhov, 1999RCD

NH4+ + Benzene, 1,4-difluoro- = (NH4+ • Benzene, 1,4-difluoro-)

By formula: H4N+ + C6H4F2 = (H4N+ • C6H4F2)

Quantity Value Units Method Reference Comment
Δr13.kcal/molPHPMSDeakyne and Meot-Ner (Mautner), 1985gas phase; Entropy change calculated or estimated; M
Quantity Value Units Method Reference Comment
Δr20.cal/mol*KN/ADeakyne and Meot-Ner (Mautner), 1985gas phase; Entropy change calculated or estimated; M

Free energy of reaction

ΔrG° (kcal/mol) T (K) Method Reference Comment
5.1395.PHPMSDeakyne and Meot-Ner (Mautner), 1985gas phase; Entropy change calculated or estimated; M

References

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering data, Notes

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

Good, Lacina, et al., 1962
Good, W.D.; Lacina, J.L.; Scott, D.W.; McCullough, J.P., Combustion calorimetry of organic fluorine compounds. The heats of combustion and formation of the difluorobenzenes, 4-fluorotoluene and m-trifluorotoluic acid, J. Phys. Chem., 1962, 66, 1529-1532. [all data]

Swarts, 1919
Swarts, F., Etudes thermochimiques sur les combinaisons organiques fluorees, J. Chim. Phys., 1919, 17, 3-70. [all data]

Lichanot, 1991
Lichanot, A., Heat capacities of fluroaniline, fluorophenol and difluorobenzene in condensed phase, Thermochim. Acta, 1991, 177, 265-272. [all data]

PCR Inc., 1990
PCR Inc., Research Chemicals Catalog 1990-1991, PCR Inc., Gainesville, FL, 1990, 1. [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]

Majer and Svoboda, 1985
Majer, V.; Svoboda, V., Enthalpies of Vaporization of Organic Compounds: A Critical Review and Data Compilation, Blackwell Scientific Publications, Oxford, 1985, 300. [all data]

Bergmann, Berkovic, et al., 1956
Bergmann, E.D.; Berkovic, S.; Ikan, R., A New Method for the Preparation of Aromatic Fluorine Compounds, J. Am. Chem. Soc., 1956, 78, 6037-9. [all data]

Goates, Ott, et al., 1976
Goates, J.R.; Ott, J.B.; Moellmer, J.F., Solid + Liquid Phase Equilibria and Solid-compound Formation in Halobenzenes + Aromatic Hydrocarbons, J. Chem. Thermodyn., 1976, 8, 217. [all data]

Osborn and Scott, 1980
Osborn, A.G.; Scott, D.W., Vapor pressures of 17 miscellanenous organic compounds, J. Chem. Thermodyn., 1980, 12, 429-438. [all data]

Basarová and Svoboda, 1991
Basarová, Pavlína; Svoboda, Václav, Calculation of heats of vaporization of halogenated hydrocarbons from saturated vapour pressure data, Fluid Phase Equilibria, 1991, 68, 13-34, https://doi.org/10.1016/0378-3812(91)85008-I . [all data]

Findlay, 1969
Findlay, T.J.V., Vapor pressures of fluorobenzenes from 5° to 50°C, J. Chem. Eng. Data, 1969, 14, 229. [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]

Deakyne and Meot-Ner (Mautner), 1985
Deakyne, C.A.; Meot-Ner (Mautner), M., Unconventional Ionic Hydrogen Bonds. 2. NH+ pi. Complexes of Onium Ions with Olefins and Benzene Derivatives, J. Am. Chem. Soc., 1985, 107, 2, 474, https://doi.org/10.1021/ja00288a034 . [all data]

Larson and McMahon, 1984
Larson, J.W.; McMahon, T.B., Hydrogen bonding in gas phase anions. An experimental investigation of the interaction between chloride ion and bronsted acids from ICR chloride exchange equilibria, J. Am. Chem. Soc., 1984, 106, 517. [all data]

Larson and McMahon, 1984, 2
Larson, J.W.; McMahon, T.B., Gas phase negative ion chemistry of alkylchloroformates, Can. J. Chem., 1984, 62, 675. [all data]

Ernstberger, Krause, et al., 1990
Ernstberger, B.; Krause, H.; Kiermeier, A.; Neusser, H.J., Multiphoton ionization and dissociation of mixed van der Waals clusters in a linear reflectron time-of-flight mass spectrometer, J. Chem. Phys., 1990, 92, 9, 5285, https://doi.org/10.1063/1.458603 . [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]

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]


Notes

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering data, References