Benzoic acid, 3-methyl-

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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
DRB - Donald R. Burgess, Jr.
DH - Eugene S. Domalski and Elizabeth D. Hearing

Quantity Value Units Method Reference Comment
Tboil536.2KN/AAldrich Chemical Company Inc., 1990BS
Quantity Value Units Method Reference Comment
Tfus384.KN/ASugunan and Thomas, 1993Uncertainty assigned by TRC = 1.5 K; TRC
Tfus384.4KN/ANoyce and Nagle, 1953Uncertainty assigned by TRC = 2. K; TRC
Tfus381.9KN/AAndrews, Lynn, et al., 1926Uncertainty assigned by TRC = 0.2 K; TRC
Quantity Value Units Method Reference Comment
Δsub23.2 ± 0.07kcal/molMEColomina, Jimenez, et al., 1986Based on data from 303. to 323. K.; AC
Δsub23.2 ± 0.07kcal/molVColomina, Jimenez, et al., 1986, 2see Colomina, Boned, et al., 1961; ALS
Δsub23.2kcal/molN/AColomina, Jimenez, et al., 1986, 2DRB

Enthalpy of vaporization

ΔvapH (kcal/mol) Temperature (K) Method Reference Comment
15.0503.AStephenson and Malanowski, 1987Based on data from 473. to 533. K. See also Mullayanov, Galagan, et al., 1970.; AC

Enthalpy of fusion

ΔfusH (kcal/mol) Temperature (K) Reference Comment
3.760381.9Acree, 1991AC
3.7596381.9Andrews, Lynn, et al., 1926, 2DH

Entropy of fusion

ΔfusS (cal/mol*K) Temperature (K) Reference Comment
9.85381.9Andrews, Lynn, et al., 1926, 2DH

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:


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

Data compiled as indicated in comments:
B - John E. Bartmess
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi

View reactions leading to C8H8O2+ (ion structure unspecified)

Quantity Value Units Method Reference Comment
Proton affinity (review)198.3kcal/molN/AHunter and Lias, 1998HL
Quantity Value Units Method Reference Comment
Gas basicity190.9kcal/molN/AHunter and Lias, 1998HL

Ionization energy determinations

IE (eV) Method Reference Comment
9.4 ± 0.2EIBenoit, 1973LLK

Appearance energy determinations

Ion AE (eV) Other Products MethodReferenceComment
C7H7+12.5 ± 0.2COOHEIBenoit, 1973LLK
C8H7O+12.4 ± 0.2OHEIBenoit, 1973LLK

De-protonation reactions

C8H7O2- + Hydrogen cation = Benzoic acid, 3-methyl-

By formula: C8H7O2- + H+ = C8H8O2

Quantity Value Units Method Reference Comment
Δr340.6 ± 2.1kcal/molG+TSKebarle and McMahon, 1977gas phase; B
Δr340.4 ± 2.1kcal/molG+TSDecouzon, Exner, et al., 1996gas phase; Relative to benzoate at 333.0 kcal/mol; B
Quantity Value Units Method Reference Comment
Δr333.6 ± 2.0kcal/molIMREKebarle and McMahon, 1977gas phase; B
Δr333.4 ± 2.0kcal/molIMREDecouzon, Exner, et al., 1996gas phase; Relative to benzoate at 333.0 kcal/mol; 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]

Sugunan and Thomas, 1993
Sugunan, S.; Thomas, B., Salting Coefficients of 2-, 3-, and 4-Methylbenzoic Acids, J. Chem. Eng. Data, 1993, 38, 520-1. [all data]

Noyce and Nagle, 1953
Noyce, D.S.; Nagle, R.J., Studies of Configuration II. The Configurations of the 3-Methylcyclohexylamines, J. Am. Chem. Soc., 1953, 75, 127. [all data]

Andrews, Lynn, et al., 1926
Andrews, D.H.; Lynn, G.; Johnston, J., The Heat Capacities and Heat of Crystallization of Some Isomeric Aromatic Compounds, J. Am. Chem. Soc., 1926, 48, 1274. [all data]

Colomina, Jimenez, et al., 1986
Colomina, M.; Jimenez, P.; Roux, M.V.; Turrion, C., Propiedades termoquimicas de derivados del acido benzoico. XIII. Presiones de vapor y entalpias de sublimacion y formacion de los acidos toluicos, An. Quim., 1986, 82, 126. [all data]

Colomina, Jimenez, et al., 1986, 2
Colomina, M.; Jimenez, P.; Roux, M.V.; Turrion, C., Propiedades termoquimicas de derivados del acido benzoico. XIII. Presiones de vapor y entalpias de sublimacion y formacion de los acidos toluicos, An. Quim., 1986, 82, 126-130. [all data]

Colomina, Boned, et al., 1961
Colomina, M.; Boned, M.L.; Turrion, C., Investigaciones termoquimicas sobre los acidos alquilbenzoicos. I. Acidos toluicos, An. Fis. Quim., 1961, 57, 655-664. [all data]

Stephenson and Malanowski, 1987
Stephenson, Richard M.; Malanowski, Stanislaw, Handbook of the Thermodynamics of Organic Compounds, 1987, https://doi.org/10.1007/978-94-009-3173-2 . [all data]

Mullayanov, Galagan, et al., 1970
Mullayanov, F.I.; Galagan, G.V.; Buz'ko, M.F.; Churkin, Yu.V.; Shiryaeva, A.A., Tr. Nauch. Issled. Inst. Neftekhim. Proizvod., 1970, 2, 95. [all data]

Acree, 1991
Acree, William E., Thermodynamic properties of organic compounds: enthalpy of fusion and melting point temperature compilation, Thermochimica Acta, 1991, 189, 1, 37-56, https://doi.org/10.1016/0040-6031(91)87098-H . [all data]

Andrews, Lynn, et al., 1926, 2
Andrews, D.H.; Lynn, G.; Johnston, J., The heat capacities and heat of crystallization of some isomeric aromatic compounds, J. Am. Chem. Soc., 1926, 48, 1274-1287. [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]

Benoit, 1973
Benoit, F., Substituent effects in mass spectrometry. III. Substituent effects in the dissociation of the molecular ions of para and meta subtituted benzoic acids, Org. Mass Spectrom., 1973, 7, 295. [all data]

Kebarle and McMahon, 1977
Kebarle, P.; McMahon, T.B., Intrinsic Acidities of Substituted Phenols and Benzoic Acids Determined by Gas Phase Proton Transfer Equilibria, J. Am. Chem. Soc., 1977, 99, 7, 2222, https://doi.org/10.1021/ja00449a032 . [all data]

Decouzon, Exner, et al., 1996
Decouzon, M.; Exner, O.; Gal, J.-F.; Maria, P.-C., Non-classical Buttressing Effect: Gas-phase Ionization of Some Methyl Substituted Benzoic Acids, J. Chem. Soc. Perkin Trans., 1996, 2, 4, 475, https://doi.org/10.1039/p29960000475 . [all data]


Notes

Go To: Top, Phase change data, Gas phase ion energetics data, References