2-Butenoic acid, 3-methyl-

• Formula: C₅H₈O₂
• Molecular weight: 100.1158
• IUPAC Standard InChI: InChI=1S/C5H8O2/c1-4(2)3-5(6)7/h3H,1-2H3,(H,6,7) Copy

  
• IUPAC Standard InChIKey: YYPNJNDODFVZLE-UHFFFAOYSA-N Copy
• CAS Registry Number: 541-47-9
• Chemical structure:
  This structure is also available as a 2d Mol file
• Other names: Crotonic acid, 3-methyl-; β-Methylcrotonic acid; β,β-Dimethylacrylic acid; Senecioic acid; 3-Methyl-2-butenoic acid; 3-Methylcrotonic acid; 3,3-Dimethylacrylic acid; (CH3)2C=CHCOOH; β,β-Dimethacrylic acid; Senecic acid; Kyselina 3-methyl-2-butenova; 3-Methylbut-2-enoic acid; NSC 2549; 3-methyl-buten-2-oic-acid
• Permanent link for this species. Use this link for bookmarking this species for future reference.
• Information on this page:
  • Phase change data
  • Gas phase ion energetics data
  • Mass spectrum (electron ionization)
  • References
  • Notes
• Other data available:
  • Reaction thermochemistry data
  • UV/Visible spectrum
  • Gas Chromatography
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Phase change data

Go To: Top, Gas phase ion energetics data, Mass spectrum (electron ionization), 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

Enthalpy of vaporization

Gas phase ion energetics data

Go To: Top, Phase change data, Mass spectrum (electron ionization), 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

Ionization energy determinations

De-protonation reactions

C₅H₇O₂^- +  =

By formula: C₅H₇O₂^- + H⁺ = C₅H₈O₂

Mass spectrum (electron ionization)

Go To: Top, Phase change data, 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 by: NIST Mass Spectrometry Data Center, William E. Wallace, director

Spectrum

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Additional Data

References

Go To: Top, Phase change data, Gas phase ion energetics data, Mass spectrum (electron ionization), Notes

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

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]

D'Souza and Teja, 1987
D'Souza, R.; Teja, A.S., The prediction of the vapor pressures of carboxylic acids, Chem. Eng. Commun., 1987, 61, 13. [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]

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]

Caldwell, Renneboog, et al., 1989
Caldwell, G.; Renneboog, R.; Kebarle, P., Gas Phase Acidities of Aliphatic Carboxylic Acids, Based on Measurements of Proton Transfer Equilibria, Can. J. Chem., 1989, 67, 4, 661, https://doi.org/10.1139/v89-092 . [all data]

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]

Notes

Go To: Top, Phase change data, Gas phase ion energetics data, Mass spectrum (electron ionization), References

• Symbols used in this document:
  

  Pc	Critical pressure
  Tboil	Boiling point
  Tc	Critical temperature
  ΔrG°	Free energy of reaction at standard conditions
  ΔrH°	Enthalpy of reaction at standard conditions
  ΔvapH	Enthalpy of vaporization

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