L-Methionine

• Formula: C₅H₁₁NO₂S
• Molecular weight: 149.211
• IUPAC Standard InChI: InChI=1S/C5H11NO2S/c1-9-3-2-4(6)5(7)8/h4H,2-3,6H2,1H3,(H,7,8)/t4-/m1/s1 Copy

  
• IUPAC Standard InChIKey: FFEARJCKVFRZRR-SCSAIBSYSA-N Copy
• CAS Registry Number: 63-68-3
• Chemical structure:
  This structure is also available as a 2d Mol file
• Stereoisomers:
  • Methionine
  • D-Methionine
  • DL-Methionine
• Other names: Methionine; Methionine, L-; γ-Methylthio-α-aminobutyric acid; Butanoic acid, 2-amino-4-(methylthio)-, (S)-; Cymethion; L-(-)-Methionine; Met; S-Methionine; 2-Amino-4-(methylthio)butyric acid; Butyric acid, 2-amino-4-(methylthio)-; L(-)-Amino-γ-methylthiobutyric acid; L-α-Amino-γ-methylmercaptobutyric acid; L-γ-Methylthio-α-aminobutyric acid; 2-Amino-4-methylthiobutanoic acid; Liquimeth; Acimethin; L-2-Amino-4-(methylthio)butyric acid; (S)-2-Amino-4-(methylthio)butanoic acid; h-Met-oh; L-Homocysteine, S-methyl-; NSC 22946; 2-Amino-4-methylthiobutanoic acid (S)-
• Permanent link for this species. Use this link for bookmarking this species for future reference.
• Information on this page:
  • Gas phase thermochemistry data
  • Condensed phase thermochemistry data
  • Phase change data
  • Gas phase ion energetics data
  • References
  • Notes
• Other data available:
  • Mass spectrum (electron ionization)
  • UV/Visible spectrum
• Data at other public NIST sites:
  • X-ray Photoelectron Spectroscopy Database, version 5.0
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Gas phase thermochemistry data

Go To: Top, Condensed phase thermochemistry data, 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: Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein

Condensed 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 by: Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein

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:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
AC - William E. Acree, Jr., James S. Chickos

Enthalpy of sublimation

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:
LBLHLM - Sharon G. Lias, John E. Bartmess, Joel F. Liebman, John L. Holmes, Rhoda D. Levin, and W. Gary Mallard
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron

Ionization energy determinations

Appearance energy determinations

References

Go To: Top, Gas phase thermochemistry data, Condensed 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.

Sabbah and Minadakis, 1981
Sabbah, R.; Minadakis, C., Thermodynamique de substances soufrees. II. Etude thermochimique de la l-cysteine et de la l-methionine, Thermochim. Acta, 1981, 43, 269-277. [all data]

Tsuzuki, Harper, et al., 1958
Tsuzuki, T.; Harper, D.O.; Hunt, H., Heats of combustion. VII. The heats of combustion of some amino acids, J. Phys. Chem., 1958, 62, 1594-1595. [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]

Svec and Clyde, 1965
Svec, H.J.; Clyde, D.D., Vapor pressures of some α-amino acids, J. Chem. Eng. Data, 1965, 10, 151. [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]

Cannington and Ham, 1983
Cannington, P.H.; Ham, N.S., He(I) and He(II) photoelectron spectra of glycine and related molecules, J. Electron Spectrosc. Relat. Phenom., 1983, 32, 139. [all data]

Svec and Junk, 1967
Svec, H.J.; Junk, G.A., Electron-impact studies of substituted alkanes, J. Am. Chem. Soc., 1967, 89, 790. [all data]

Akopyan and Loginov, 1967
Akopyan, M.E.; Loginov, Yy.V., Mass-spectrometric study of the phoionization of free α-aminoacids, High Energy Chem., 1967, 1, 83, In original 97. [all data]

Notes

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

• Symbols used in this document:
  

  AE	Appearance energy
  ΔcH°solid	Enthalpy of combustion of solid at standard conditions
  ΔfH°gas	Enthalpy of formation of gas at standard conditions
  ΔfH°solid	Enthalpy of formation of solid at standard conditions
  ΔsubH	Enthalpy of sublimation
  ΔsubH°	Enthalpy of sublimation at standard conditions

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