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
  • Mass spectrum (electron ionization)
  • UV/Visible spectrum
  • References
  • Notes
• Options:
  • Switch to SI units

Data at NIST subscription sites:

• NIST / TRC Web Thermo Tables, professional edition (thermophysical and thermochemical data)

NIST subscription sites provide data under the NIST Standard Reference Data Program, but require an annual fee to access. The purpose of the fee is to recover costs associated with the development of data collections included in such sites. Your institution may already be a subscriber. Follow the links above to find out more about the data in these sites and their terms of usage.

Gas phase thermochemistry data

Go To: Top, Condensed phase thermochemistry data, Phase change data, Gas phase ion energetics data, Mass spectrum (electron ionization), UV/Visible spectrum, NIST Free Links, 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

Go To: Top, Gas phase thermochemistry data, Phase change data, Gas phase ion energetics data, Mass spectrum (electron ionization), UV/Visible spectrum, NIST Free Links, 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

Phase change data

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Gas phase ion energetics data, Mass spectrum (electron ionization), UV/Visible spectrum, NIST Free Links, 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:
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

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Mass spectrum (electron ionization), UV/Visible spectrum, NIST Free Links, 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:
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

Mass spectrum (electron ionization)

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Gas phase ion energetics data, UV/Visible spectrum, NIST Free Links, 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

Notice: This spectrum may be better viewed with a Javascript and HTML 5 enabled browser.

For Zoom

1.) Enter the desired X axis range (e.g., 100, 200)

2.) Check here for automatic Y scaling

3.) Press here to zoom

Additional Data

UV/Visible spectrum

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Gas phase ion energetics data, Mass spectrum (electron ionization), NIST Free Links, 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: Victor Talrose, Alexander N. Yermakov, Alexy A. Usov, Antonina A. Goncharova, Axlexander N. Leskin, Natalia A. Messineva, Natalia V. Trusova, Margarita V. Efimkina

Spectrum

Notice: This spectrum may be better viewed with a Javascript and HTML 5 enabled browser.

For Zoom

1.) Enter the desired X axis range (e.g., 100, 200)

2.) Check here for automatic Y scaling

3.) Press here to zoom

Additional Data

References

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Gas phase ion energetics data, Mass spectrum (electron ionization), UV/Visible spectrum, NIST Free Links, 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]

Johnson, 1971
Johnson, E.A., UV atlas of organic compounds, 1971, 5, J2/4. [all data]

Notes

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Gas phase ion energetics data, Mass spectrum (electron ionization), UV/Visible spectrum, NIST Free Links, 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
• The National Institute of Standards and Technology (NIST) uses its best efforts to deliver a high quality copy of the Database and to verify that the data contained therein have been selected on the basis of sound scientific judgment. However, NIST makes no warranties to that effect, and NIST shall not be liable for any damage that may result from errors or omissions in the Database.
• Customer support for NIST Standard Reference Data products.