Benzoic acid, 4-methyl-

• Formula: C₈H₈O₂
• Molecular weight: 136.1479
• IUPAC Standard InChI: InChI=1S/C8H8O2/c1-6-2-4-7(5-3-6)8(9)10/h2-5H,1H3,(H,9,10) Copy

  
• IUPAC Standard InChIKey: LPNBBFKOUUSUDB-UHFFFAOYSA-N Copy
• CAS Registry Number: 99-94-5
• 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: p-Toluic acid; p-Methylbenzoic acid; p-Toluylic acid; Crithminic acid; 4-Methylbenzoic acid; 4-Toluic acid; para-Toluic acid; NSC 2215; p-Carboxytoluene; p-Tolylcarboxylic acid
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• Information on this page:
  • Gas phase thermochemistry data
  • Phase change data
  • Gas phase ion energetics data
  • IR Spectrum
  • Gas Chromatography
  • References
  • Notes
• Other data available:
  • Condensed phase thermochemistry data
  • Reaction thermochemistry data
  • Mass spectrum (electron ionization)
  • UV/Visible spectrum
• Data at other public NIST sites:
  • Gas Phase Kinetics Database
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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.

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

Enthalpy of fusion

Entropy of fusion

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)

Ionization energy determinations

Appearance energy determinations

De-protonation reactions

C₈H₇O₂^- +  =

By formula: C₈H₇O₂^- + H⁺ = C₈H₈O₂

IR Spectrum

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Data compiled by: Coblentz Society, Inc.

• SOLUTION (1% CCl4 FOR 5000-1330, 1% CS2 FOR 1330-625 CM^-1); Not specified, most likely a prism, grating, or hybrid spectrometer.; DIGITIZED BY NIST FROM HARD COPY; 4 cm^-1 resolution

Data compiled by: NIST Mass Spectrometry Data Center, William E. Wallace, director

• gas

Gas Chromatography

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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: NIST Mass Spectrometry Data Center, William E. Wallace, director

Normal alkane RI, non-polar column, temperature ramp

View large format table.

References

Go To: Top, Gas phase thermochemistry data, Phase change data, Gas phase ion energetics data, IR Spectrum, Gas Chromatography, 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]

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]

Ipatieff, Corson, et al., 1936
Ipatieff, V.N.; Corson, B.B.; Pines, H., Influence of Sulfuric Acid Concentration upon Reaction between Olefins and Benzene, J. Am. Chem. Soc., 1936, 58, 919-22. [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]

Monte, Almeida, et al., 2004
Monte, Manuel J.S.; Almeida, Ana R.R.P.; Ribeiro da Silva, Manuel A.V., Thermodynamic study of the sublimation of eight 4-n-alkylbenzoic acids, The Journal of Chemical Thermodynamics, 2004, 36, 5, 385-392, https://doi.org/10.1016/j.jct.2004.02.001 . [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]

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]

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, 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]

Ali, Wurster, et al., 2008
Ali, N.A.A.; Wurster, M.; Arnold, N.; Teichert, A.; Schmidt, J.; Lindequist, U.; Wessjohann, L., Chemical composition and biological activities of essential oils from the oleogum resins of three endemic soqotraen Boswellia species, Rec. Nat. Prod., 2008, 2, 1, 6-12. [all data]

Awadi Ali, Wurster, et al., 2008
Awadi Ali, N.A.; Wurster, M.; Arnold, N.; Teicher, A.; Schmidt, J.; Lindequist, U.; Wessjohann, L., Chemical composition and biological activity of essential oils from the Oleogum resins of three endemic soqotraen Boswellia species, Rec. Nat. Prod., 2008, 2, 1, 6-12. [all data]

Notes

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

• Symbols used in this document:
  

  AE	Appearance energy
  Tboil	Boiling point
  Tfus	Fusion (melting) point
  ΔfH°gas	Enthalpy of formation of gas at standard conditions
  ΔfusH	Enthalpy of fusion
  ΔfusS	Entropy of fusion
  ΔrG°	Free energy of reaction at standard conditions
  ΔrH°	Enthalpy of reaction at standard conditions
  ΔsubH°	Enthalpy of sublimation at standard conditions

• Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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