2-Propenoic acid, 2-methyl-

• Formula: C₄H₆O₂
• Molecular weight: 86.0892
• IUPAC Standard InChI: InChI=1S/C4H6O2/c1-3(2)4(5)6/h1H2,2H3,(H,5,6) Copy

  
• IUPAC Standard InChIKey: CERQOIWHTDAKMF-UHFFFAOYSA-N Copy
• CAS Registry Number: 79-41-4
• 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: Methacrylic acid; α-Methylacrylic acid; Methylacrylic acid; 2-Methyl-2-propenoic acid; 2-Methylacrylic acid; CH2=C(CH3)COOH; 2-Methylpropenoic acid; Methacrylic acid glacial; α-Methacrylic acid; Acrylic acid, 2-methyl-; Propionic acid, 2-methylene-; Kyselina methakrylova; NSC 7393
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• Information on this page:
  • Reaction thermochemistry data
  • Gas phase ion energetics data
  • Gas Chromatography
  • References
  • Notes
• Other data available:
  • Gas phase thermochemistry data
  • Condensed phase thermochemistry data
  • Phase change data
  • IR Spectrum
  • Mass spectrum (electron ionization)
  • UV/Visible spectrum
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Reaction 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:
B - John E. Bartmess
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein

Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. A general reaction search form is also available. Future versions of this site may rely on reaction search pages in place of the enumerated reaction displays seen below.

Individual Reactions

C₄H₅O₂^- +  =

By formula: C₄H₅O₂^- + H⁺ = C₄H₆O₂

 +  =

By formula: H₂ + C₄H₆O₂ = C₄H₈O₂

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
LBLHLM - Sharon G. Lias, John E. Bartmess, Joel F. Liebman, John L. Holmes, Rhoda D. Levin, and W. Gary Mallard

Ionization energy determinations

Appearance energy determinations

De-protonation reactions

C₄H₅O₂^- +  =

By formula: C₄H₅O₂^- + H⁺ = C₄H₆O₂

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

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References

Go To: Top, Reaction thermochemistry data, Gas phase ion energetics data, Gas Chromatography, Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Graul, Schnute, et al., 1990
Graul, S.T.; Schnute, M.E.; Squires, R.R., Gas-Phase Acidities of Carboxylic Acids and Alcohols from Collision-Induced Dissociation of Dimer Cluster Ions, Int. J. Mass Spectrom. Ion Proc., 1990, 96, 2, 181, https://doi.org/10.1016/0168-1176(90)87028-F . [all data]

Skinner and Snelson, 1959
Skinner, H.A.; Snelson, A., Heats of hydrogenation Part 3., Trans. Faraday Soc., 1959, 55, 405-407. [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]

Holmes, Terlouw, et al., 1979
Holmes, J.L.; Terlouw, J.K.; Vijfhuizen, P.C.; A'Campo, C., Metastable ion studies XII-Molecular and fragment ion structures for isomeric C₄H₆O₂ acids, Org. Mass Spectrom., 1979, 14, 204. [all data]

Burgers, Holmes, et al., 1982
Burgers, P.C.; Holmes, J.L.; Lossing, F.P.; Mommers, A.A.; Povel, F.R.; Terlouw, J.K., Isomeric and tautomeric [C₄H₄O]⁺ ions. Their thermochemistry and collisionally induced fragmentation characteristics, Can. J. Chem., 1982, 60, 2246. [all data]

Meynier, Novelli, et al., 1999
Meynier, A.; Novelli, E.; Chissolinim, R.; Zanardi, E.; Gandemer, G., Volatile compounds of commercial Milano salami, Meat Sci., 1999, 51, 2, 175-183, https://doi.org/10.1016/S0309-1740(98)00122-3 . [all data]

Notes

Go To: Top, Reaction thermochemistry data, Gas phase ion energetics data, Gas Chromatography, References

• Symbols used in this document:
  

  AE	Appearance energy
  ΔrG°	Free energy of reaction at standard conditions
  ΔrH°	Enthalpy of reaction at standard conditions

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