Benzene, 1,2-difluoro-
- Formula: C6H4F2
- Molecular weight: 114.0928
- IUPAC Standard InChIKey: GOYDNIKZWGIXJT-UHFFFAOYSA-N
- CAS Registry Number: 367-11-3
- 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, o-difluoro-; o-Difluorobenzene; 1,2-Difluorobenzene; ortho-Difluorobenzene
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Phase change data
Go To: Top, 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 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 |
---|---|---|---|---|---|
Tboil | 365.2 | K | N/A | Aldrich Chemical Company Inc., 1990 | BS |
Tboil | 364. to 365. | K | N/A | PCR Inc., 1990 | BS |
Tboil | 367.1 | K | N/A | Majer and Svoboda, 1985 | |
Quantity | Value | Units | Method | Reference | Comment |
Ttriple | 226.010 | K | N/A | Scott, Messerly, et al., 1963 | Uncertainty assigned by TRC = 0.01 K; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Tc | 557.3 | K | N/A | Majer and Svoboda, 1985 | |
Quantity | Value | Units | Method | Reference | Comment |
ΔvapH° | 36.24 | kJ/mol | N/A | Majer and Svoboda, 1985 | |
ΔvapH° | 36.2 | kJ/mol | N/A | Boublik, Fried, et al., 1984 | Based on data from 300. to 400. K. See also Basarová and Svoboda, 1991.; AC |
ΔvapH° | 36.2 | kJ/mol | V | Scott, Messerly, et al., 1963, 2 | hfusion=2.64kcal/mol; ALS |
ΔvapH° | 36.2 ± 0.08 | kJ/mol | V | Good, Lacina, et al., 1962 | Corrected for CODATA value of ΔfH; ALS |
Reduced pressure boiling point
Tboil (K) | Pressure (bar) | Reference | Comment |
---|---|---|---|
364.7 | 1.00 | Weast and Grasselli, 1989 | BS |
Enthalpy of vaporization
ΔvapH (kJ/mol) | Temperature (K) | Method | Reference | Comment |
---|---|---|---|---|
32.21 | 367.1 | N/A | Majer and Svoboda, 1985 | |
35.5 | 319. | EB | Scott, Messerly, et al., 1963, 2 | Based on data from 304. to 403. K. See also Boublik, Fried, et al., 1984.; AC |
34.6 ± 0.1 | 327. | C | Scott, Messerly, et al., 1963, 2 | AC |
33.5 ± 0.1 | 345. | C | Scott, Messerly, et al., 1963, 2 | AC |
32.2 ± 0.1 | 367. | C | Scott, Messerly, et al., 1963, 2 | AC |
Enthalpy of vaporization
ΔvapH =
A exp(-βTr) (1 − Tr)β
ΔvapH =
Enthalpy of vaporization (at saturation pressure)
(kJ/mol)
Tr = reduced temperature (T / Tc)
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Temperature (K) | A (kJ/mol) | β | Tc (K) | Reference | Comment |
---|---|---|---|---|---|
298. to 367. | 51.35 | 0.2691 | 557.3 | Majer and Svoboda, 1985 |
Antoine Equation Parameters
log10(P) = A − (B / (T + C))
P = vapor pressure (bar)
T = temperature (K)
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Temperature (K) | A | B | C | Reference | Comment |
---|---|---|---|---|---|
304.31 to 403.40 | 4.14521 | 1310.271 | -50.563 | Scott, Messerly, et al., 1963, 3 | Coefficents calculated by NIST from author's data. |
Enthalpy of fusion
ΔfusH (kJ/mol) | Temperature (K) | Reference | Comment |
---|---|---|---|
11.046 | 226.01 | Scott, Messerly, et al., 1963, 3 | DH |
11.05 | 226. | Domalski and Hearing, 1996 | AC |
Entropy of fusion
ΔfusS (J/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
48.87 | 226.01 | Scott, Messerly, et al., 1963, 3 | DH |
Gas phase ion energetics data
Go To: Top, Phase change data, 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
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) | 9.29 ± 0.01 | eV | N/A | N/A | L |
Quantity | Value | Units | Method | Reference | Comment |
Proton affinity (review) | 731.2 | kJ/mol | N/A | Hunter and Lias, 1998 | HL |
Quantity | Value | Units | Method | Reference | Comment |
Gas basicity | 703.5 | kJ/mol | N/A | Hunter and Lias, 1998 | HL |
Ionization energy determinations
IE (eV) | Method | Reference | Comment |
---|---|---|---|
9.284 ± 0.008 | EQ | Lias and Ausloos, 1978 | LLK |
9.30 | S | Gilbert and Sandorfy, 1974 | LLK |
9.74 ± 0.02 | EI | Momigny and Wirtz-Cordier, 1962 | RDSH |
9.31 | PI | Bralsford, Harris, et al., 1960 | RDSH |
9.30 | PE | Streets and Ceasar, 1973 | Vertical value; LLK |
9.6 ± 0.03 | PE | Klessinger, 1972 | Vertical value; LLK |
Appearance energy determinations
Ion | AE (eV) | Other Products | Method | Reference | Comment |
---|---|---|---|---|---|
C4H2F2+ | 15.27 | C2H2 | EI | Momigny and Wirtz-Cordier, 1962 | RDSH |
De-protonation reactions
C6H3F2- + =
By formula: C6H3F2- + H+ = C6H4F2
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 1580. ± 9.2 | kJ/mol | G+TS | Buker, Nibbering, et al., 1997 | gas phase; B |
ΔrH° | 1582. ± 13. | kJ/mol | G+TS | Briscese and Riveros, 1975 | gas phase; Between EtO-, iPrO-; value altered from reference due to change in acidity scale; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 1546. ± 8.4 | kJ/mol | IMRE | Buker, Nibbering, et al., 1997 | gas phase; B |
ΔrG° | 1547. ± 13. | kJ/mol | IMRB | Briscese and Riveros, 1975 | gas phase; Between EtO-, iPrO-; value altered from reference due to change in acidity scale; B |
References
Go To: Top, Phase change data, Gas phase ion energetics data, 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]
PCR Inc., 1990
PCR Inc.,
Research Chemicals Catalog 1990-1991, PCR Inc., Gainesville, FL, 1990, 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]
Scott, Messerly, et al., 1963
Scott, D.W.; Messerly, J.F.; Todd, S.S.; Hossenlopp, I.A.; Osborn, A.G.; McCullough, J.P.,
1,2-difluorobenzene: chemical thermodynamic properties and vibrational assignment,
J. Chem. Phys., 1963, 38, 532-9. [all data]
Boublik, Fried, et al., 1984
Boublik, T.; Fried, V.; Hala, E.,
The Vapour Pressures of Pure Substances: Selected Values of the Temperature Dependence of the Vapour Pressures of Some Pure Substances in the Normal and Low Pressure Region, 2nd ed., Elsevier, New York, 1984, 972. [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]
Scott, Messerly, et al., 1963, 2
Scott, D.W.; Messerly, J.F.; Todd, S.S.; Hossenlopp, I.A.; Osborn, A.; McCullough, J.P.,
1,2-Difluorobenzene: Chemical thermodynamic properties and vibrationnal assignment,
J. Chem. Phys., 1963, 38, 532. [all data]
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]
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]
Scott, Messerly, et al., 1963, 3
Scott, D.W.; Messerly, J.F.; Todd, S.S.; Hossenlopp, I.A.; Osborn, A.; McCullough, J.P.,
1,2-Difluorobenzene: Chemical thermodynamic properties and vibrational assignment,
J. Chem. Phys., 1963, 38, 532-539. [all data]
Domalski and Hearing, 1996
Domalski, Eugene S.; Hearing, Elizabeth D.,
Heat Capacities and Entropies of Organic Compounds in the Condensed Phase. Volume III,
J. Phys. Chem. Ref. Data, 1996, 25, 1, 1, https://doi.org/10.1063/1.555985
. [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]
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]
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]
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]
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]
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]
Notes
Go To: Top, Phase change data, Gas phase ion energetics data, References
- Symbols used in this document:
AE Appearance energy IE (evaluated) Recommended ionization energy Tboil Boiling point Tc Critical temperature 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 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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