L-Cysteine

• Formula: C₃H₇NO₂S
• Molecular weight: 121.158
• IUPAC Standard InChI: InChI=1S/C3H7NO2S/c4-2(1-7)3(5)6/h2,7H,1,4H2,(H,5,6)/t2-/m1/s1 Copy

  
• IUPAC Standard InChIKey: XUJNEKJLAYXESH-UWTATZPHSA-N Copy
• CAS Registry Number: 52-90-4
• Chemical structure:
  This structure is also available as a 2d Mol file or as a computed 3d SD file
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• Stereoisomers:
  • dl-Cysteine
• Other names: Cysteine, L-; β-Mercaptoalanine; Cystein; Cysteine; Half-cystine; L-(+)-Cysteine; L-Alanine, 3-mercapto-; NSC-8746; Propanoic Acid, 2-amino-3-mercapto-, (R)-; Thioserine; (R)-2-Amino-3-mercaptopropanoic acid; α-Amino-β-thiolpropionic acid; (R)-Cysteine; 2-Amino-3-mercaptopropionic acid; L-Cys
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• Information on this page:
  • Condensed phase thermochemistry data
  • Mass spectrum (electron ionization)
  • UV/Visible spectrum
  • References
  • Notes
• Other data available:
  • Reaction thermochemistry data
  • Gas phase ion energetics data
• Data at other public NIST sites:
  • X-ray Photoelectron Spectroscopy Database, version 5.0
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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 as indicated in comments:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DH - Eugene S. Domalski and Elizabeth D. Hearing

Constant pressure heat capacity of solid

Mass spectrum (electron ionization)

Go To: Top, Condensed phase thermochemistry data, UV/Visible spectrum, 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

UV/Visible spectrum

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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: Victor Talrose, Alexander N. Yermakov, Alexy A. Usov, Antonina A. Goncharova, Axlexander N. Leskin, Natalia A. Messineva, Natalia V. Trusova, Margarita V. Efimkina

Spectrum

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Additional Data

References

Go To: Top, Condensed phase thermochemistry data, Mass spectrum (electron ionization), UV/Visible spectrum, 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]

Becker and Roth, 1934
Becker, G.; Roth, W.A., Zur bestimmung der verbrennungswarme von organischen schwefelverbindunge, Z. Phys. Chem., 1934, 169, 287-296. [all data]

Sunner, 1946
Sunner, S., Determination of combustion heats of organo-sulphur compounds, Svensk. Kim. Tidr., 1946, 58, 71-81. [all data]

Cox and Pilcher, 1970
Cox, J.D.; Pilcher, G., Thermochemistry of Organic and Organometallic Compounds, Academic Press, New York, 1970, 1-636. [all data]

Huffman and Ellis, 1935
Huffman, H.M.; Ellis, E.L., Thermal Data. II. The heats of combustion of l-cysteine, of l-cystine, β-thiolactic acid and β,β'-dithiodilactic acid, J. Am. Chem. Soc., 1935, 57, 41-46. [all data]

Huffman and Ellis, 1935, 2
Huffman, H.M.; Ellis, E.L., Thermal data. III. The heat capacities, entropies and free energies of four organic compounds containing sulfur, J. Am. Chem. Soc., 1935, 57, 46-48. [all data]

Johnson, 1971
Johnson, E.A., UV atlas of organic compounds, 1971, 5, J2/3. [all data]

Notes

Go To: Top, Condensed phase thermochemistry data, Mass spectrum (electron ionization), UV/Visible spectrum, References

• Symbols used in this document:
  

  Cp,solid	Constant pressure heat capacity of solid
  S°solid,1 bar	Entropy of solid at standard conditions (1 bar)
  ΔcH°solid	Enthalpy of combustion of solid at standard conditions
  ΔfH°solid	Enthalpy of formation of solid at standard conditions

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