Benzoic acid, 2-methyl-

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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 as indicated in comments:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DRB - Donald R. Burgess, Jr.

Quantity Value Units Method Reference Comment
Δfgas-76.63 ± 0.36kcal/molCcbColomina, Jimenez, et al., 1986see Colomina, Boned, et al., 1961 and Colomina, Perez Ossorio, et al., 1959; ALS
Δfgas-76.63kcal/molN/ACorral, 1960Value computed using ΔfHsolid° value of -416.5±0.9 kj/mol from Corral, 1960 and ΔsubH° value of 95.9 kj/mol from Colomina, Jimenez, et al., 1986.; DRB
Δfgas-79.16kcal/molN/ABreitenbach and Derkosch, 1951Value computed using ΔfHsolid° value of -427.1±3.8 kj/mol from Breitenbach and Derkosch, 1951 and ΔsubH° value of 95.9 kj/mol from Colomina, Jimenez, et al., 1986.; DRB

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
Tboil531.7KN/AAldrich Chemical Company Inc., 1990BS
Quantity Value Units Method Reference Comment
Tfus380.KN/ASugunan and Thomas, 1993Uncertainty assigned by TRC = 1.5 K; TRC
Tfus376.50KN/ADomanska and Hofman, 1985Uncertainty assigned by TRC = 0.05 K; TRC
Tfus377.65KN/ADoering and Bragole, 1966Uncertainty assigned by TRC = 2. K; TRC
Tfus376.9KN/AAndrews, Lynn, et al., 1926Uncertainty assigned by TRC = 0.3 K; TRC
Quantity Value Units Method Reference Comment
Δsub22.9 ± 0.02kcal/molMEColomina, Jimenez, et al., 1986, 2Based on data from 297. to 337. K.; AC
Δsub22.9 ± 0.02kcal/molVColomina, Jimenez, et al., 1986see Colomina, Boned, et al., 1961 and Colomina, Perez Ossorio, et al., 1959; ALS
Δsub22.9kcal/molN/AColomina, Jimenez, et al., 1986DRB

Enthalpy of fusion

ΔfusH (kcal/mol) Temperature (K) Reference Comment
4.821376.9Acree, 1991AC
4.8207376.9Andrews, Lynn, et al., 1926, 2DH

Entropy of fusion

ΔfusS (cal/mol*K) Temperature (K) Reference Comment
12.8376.9Andrews, 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

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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

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)200.5kcal/molN/AHunter and Lias, 1998HL
Quantity Value Units Method Reference Comment
Gas basicity193.1kcal/molN/AHunter and Lias, 1998HL

Ionization energy determinations

IE (eV) Method Reference Comment
9.1PEMeeks, Wahlborg, et al., 1981LLK
9.4PEMeeks, Wahlborg, et al., 1981Vertical value; LLK

De-protonation reactions

C8H7O2- + Hydrogen cation = Benzoic acid, 2-methyl-

By formula: C8H7O2- + H+ = C8H8O2

Quantity Value Units Method Reference Comment
Δr339.2 ± 2.2kcal/molG+TSKebarle and McMahon, 1977gas phase; B
Quantity Value Units Method Reference Comment
Δr332.1 ± 2.0kcal/molIMREKebarle and McMahon, 1977gas phase; B
Δr332.4 ± 2.0kcal/molIMREDecouzon, Ertl, et al., 1993gas phase; B

References

Go To: Top, Gas phase thermochemistry data, 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.

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, 126-130. [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]

Colomina, Perez Ossorio, et al., 1959
Colomina, M.; Perez Ossorio, R.; Boned, M.L.; Panea, M.; Turrion, C., Thermochemical investigations on methylsubstituted benzoic acids, Rpt. for the U.S. Dept. of the Army, European Research Office contract no. DA-91-508-EUC-358 by Instituto de Quimica Fisica Madrid, Spain, 1959, 1-36. [all data]

Corral, 1960
Corral, L.B., Investigaciones termoquimicas sobre los acidos toluicos y dimetilbenzoicos, Rev. R. Acad. Cienc., 1960, 54, 365-403. [all data]

Breitenbach and Derkosch, 1951
Breitenbach, J.W.; Derkosch, J., Verbrennungswarmen von peroxyden und verwandten verbindungen sowie von polystrolen, Monatsh. Chem., 1951, 82, 177-179. [all data]

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]

Domanska and Hofman, 1985
Domanska, U.; Hofman, T., Correlations for the solubility of normal alkanoic acids and o-tolui acid in binary solvent mixtures, J. Solution Chem., 1985, 14, 531-47. [all data]

Doering and Bragole, 1966
Doering, W. vonE.; Bragole, R.A., The Carbon Analogue of the Clasien Rearrangement of Phenyl Allyl Ether. Equilibrium of Butenylbenzenes and ortho-Propenyltoluenes, Tetrahedron, 1966, 27, 385. [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, 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. [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]

Meeks, Wahlborg, et al., 1981
Meeks, J.; Wahlborg, A.; McGlynn, S.P., Photoelectron spectroscopy of carbonyls: Benzoic acid and its derivatives, J. Electron Spectrosc. Relat. Phenom., 1981, 22, 43. [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, Ertl, et al., 1993
Decouzon, M.; Ertl, P.; Exner, O.; Gal, J.F.; Maria, P.C., Concepts of Sterically Hindered Resonance and Buttressing Effect - Gas-Phase Acidities of Methyl-Substituted Benzoic Acids and Basicities of, J. Am. Chem. Soc., 1993, 115, 25, 12071, https://doi.org/10.1021/ja00078a052 . [all data]


Notes

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