Benzene, 1,3-difluoro-
- Formula: C6H4F2
- Molecular weight: 114.0928
- IUPAC Standard InChIKey: UEMGWPRHOOEKTA-UHFFFAOYSA-N
- CAS Registry Number: 372-18-9
- 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, m-difluoro-; m-Difluorobenzene; 1,3-Difluorobenzene; meta-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
CAL - James S. Chickos, William E. Acree, Jr., Joel F. Liebman, Students of Chem 202 (Introduction to the Literature of Chemistry), University of Missouri -- St. Louis
DH - Eugene S. Domalski and Elizabeth D. Hearing
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
Tboil | 354. to 356. | K | N/A | PCR Inc., 1990 | BS |
Tboil | 356.2 | K | N/A | Weast and Grasselli, 1989 | BS |
Tboil | 355.7 | K | N/A | Majer and Svoboda, 1985 | |
Quantity | Value | Units | Method | Reference | Comment |
Ttriple | 204.03 | K | N/A | Messerly and Finke, 1970 | Crystal phase 1 phase; Uncertainty assigned by TRC = 0.02 K; TRC |
Quantity | Value | Units | Method | Reference | Comment |
ΔvapH° | 8.291 | kcal/mol | N/A | Majer and Svoboda, 1985 | |
ΔvapH° | 8.27 | kcal/mol | N/A | Osborn and Scott, 1980 | Based on data from 310. to 400. K. See also Basarová and Svoboda, 1991.; AC |
ΔvapH° | 8.258 | kcal/mol | V | Findlay, 1969 | ALS |
ΔvapH° | 8.29 ± 0.05 | kcal/mol | V | Good, Lacina, et al., 1962 | Corrected for CODATA value of ΔfH; ALS |
Enthalpy of vaporization
ΔvapH (kcal/mol) | Temperature (K) | Reference | Comment |
---|---|---|---|
7.43 | 355.7 | Majer and Svoboda, 1985 |
Enthalpy of fusion
ΔfusH (kcal/mol) | Temperature (K) | Reference | Comment |
---|---|---|---|
2.05 | 204. | Domalski and Hearing, 1996 | AC |
Entropy of fusion
ΔfusS (cal/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
1.06 | 186.8 | Domalski and Hearing, 1996 | CAL |
10.05 | 204.0 |
Enthalpy of phase transition
ΔHtrs (kcal/mol) | Temperature (K) | Initial Phase | Final Phase | Reference | Comment |
---|---|---|---|---|---|
0.19767 | 186.77 | crystaline, II | crystaline, I | Messerly and Finke, 1970, 2 | DH |
2.0509 | 204.03 | crystaline, I | liquid | Messerly and Finke, 1970, 2 | DH |
Entropy of phase transition
ΔStrs (cal/mol*K) | Temperature (K) | Initial Phase | Final Phase | Reference | Comment |
---|---|---|---|---|---|
1.058 | 186.77 | crystaline, II | crystaline, I | Messerly and Finke, 1970, 2 | DH |
10.05 | 204.03 | crystaline, I | liquid | Messerly and Finke, 1970, 2 | 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) | 9.33 ± 0.02 | eV | N/A | N/A | L |
Quantity | Value | Units | Method | Reference | Comment |
Proton affinity (review) | 179.2 | kcal/mol | N/A | Hunter and Lias, 1998 | HL |
Quantity | Value | Units | Method | Reference | Comment |
Gas basicity | 173. | kcal/mol | N/A | Hunter and Lias, 1998 | HL |
Ionization energy determinations
IE (eV) | Method | Reference | Comment |
---|---|---|---|
9.2 | PE | Maier and Thommen, 1981 | LLK |
9.332 ± 0.004 | EQ | Lias and Ausloos, 1978 | LLK |
9.35 | S | Gilbert and Sandorfy, 1974 | LLK |
9.78 ± 0.02 | EI | Momigny and Wirtz-Cordier, 1962 | RDSH |
9.32 | 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+ | 15.30 | C2H2 | EI | Momigny and Wirtz-Cordier, 1962 | RDSH |
De-protonation reactions
C6H3F2- + =
By formula: C6H3F2- + H+ = C6H4F2
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 374.0 ± 2.1 | kcal/mol | G+TS | Buker, Nibbering, et al., 1997 | gas phase; B |
ΔrH° | <376.55 ± 0.30 | kcal/mol | G+TS | Briscese and Riveros, 1975 | gas phase; < iPrOH; value altered from reference due to change in acidity scale; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 366.3 ± 2.0 | kcal/mol | IMRE | Buker, Nibbering, et al., 1997 | gas phase; B |
ΔrG° | <368.80 | kcal/mol | IMRB | Briscese and Riveros, 1975 | gas phase; < iPrOH; 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.
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]
Messerly and Finke, 1970
Messerly, J.F.; Finke, H.L.,
hexafluorobenzene and 1,3-difluorobenzene low temperature calorimetric studies and chemical thermodynamic properties,
J. Chem. Thermodyn., 1970, 2, 867-80. [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]
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]
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]
Messerly and Finke, 1970, 2
Messerly, J.F.; Finke, H.L.,
Hexafluorobenzene and 1,3-difluorobenzene. Low-temperature calorimetric studies and chemical thermodynamic properties,
J. Chem. Thermodynam., 1970, 2, 867-880. [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]
Maier and Thommen, 1981
Maier, J.P.; Thommen, F.,
Fluorescence quantum yields and lifetimes of fluorobenzene cations in selected levels of their B and C states determined by photoelectron-photoion coincidence spectroscopy,
Chem. Phys., 1981, 57, 319. [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]
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 Ttriple Triple point temperature ΔHtrs Enthalpy of phase transition ΔStrs Entropy of phase transition 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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