Cystine

• Formula: C₆H₁₂N₂O₄S₂
• Molecular weight: 240.300
• IUPAC Standard InChI: InChI=1S/C6H12N2O4S2/c7-3(5(9)10)1-13-14-2-4(8)6(11)12/h3-4H,1-2,7-8H2,(H,9,10)(H,11,12)/t3-,4-/m1/s1 Copy

  
• IUPAC Standard InChIKey: LEVWYRKDKASIDU-QWWZWVQMSA-N Copy
• CAS Registry Number: 56-89-3
• Chemical structure:
  This structure is also available as a 2d Mol file
• Stereoisomers:
  • DL-Cystine
• Other names: l-Cystine; β,β'-Diamino-β,β'-dicarboxydiethyl disulfide; β,β'-Dithiodialanine; Alanine, 3,3'-dithiobis-; Alanine, 3,3'-dithiodi-; Bis(β-amino-β-carboxyethyl) disulfide; Cysteine disulfide; Cystin; Cystine acid; Cystine, L-; Dicysteine; Oxidized L-cysteine; Propanoic acid, 3,3'-dithiobis(2-amino-, (R-(R*,R*))-; 3,3'-Dithiobis(2-aminopropanoic acid); 3,3'-Dithiodialanine; β,β'-Dithiobisalanine; 3,3'-Dithiobis(2-aminopropionic acid); L-3,3'-dithiodialanine; (R-(R*,R*))-3,3'-Dithiobis(2-aminopropanoic acid); (-)-Cystine; L-Alanine, 3,3'-dithiobis-; L-Cysteine disulfide; L-Cystin; NSC 13203
• Permanent link for this species. Use this link for bookmarking this species for future reference.
• Information on this page:
  • Condensed phase thermochemistry data
  • Mass spectrum (electron ionization)
  • References
  • Notes
• Other data available:
  • IR Spectrum
  • UV/Visible spectrum
• Data at other public NIST sites:
  • X-ray Photoelectron Spectroscopy Database, version 5.0
  • X-ray Photoelectron Spectroscopy Database, version 5.0
  • X-ray Photoelectron Spectroscopy Database, version 5.0
• Options:
  • Switch to calorie-based 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.

Condensed phase thermochemistry data

Go To: Top, 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:
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, 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

References

Go To: Top, Condensed phase thermochemistry 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.

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]

Emery and Benedict, 1911
Emery, A.G.; Benedict, F.G., The heat of combustion of compounds of physiological importance, Am. J. Physiol., 1911, 28, 301-307. [all data]

Hutchens, Cole, et al., 1964
Hutchens, J.O.; Cole, A.G.; Stout, J.W., Heat capacities and entropies of L-cystine and L-methionine. The transition of L-methionine near 305.5 K, J. Biol. Chem., 1964, 239, 591-595. [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]

Notes

Go To: Top, Condensed phase thermochemistry data, Mass spectrum (electron ionization), 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
• 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.