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
- IUPAC Standard InChIKey: XUJNEKJLAYXESH-UWTATZPHSA-N
- 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
The 3d structure may be viewed using Java or Javascript. - Stereoisomers:
- 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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Condensed phase thermochemistry data
Go To: Top, 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
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔfH°solid | -534.08 ± 0.62 | kJ/mol | Ccr | Sabbah and Minadakis, 1981 | ALS |
| ΔfH°solid | -567.4 | kJ/mol | Ccb | Becker and Roth, 1934 | hf_H2SO4.10,000H2O=-900.752 kJ/mol; ALS |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔcH°solid | -2248.84 ± 0.55 | kJ/mol | Ccr | Sabbah and Minadakis, 1981 | ALS |
| ΔcH°solid | -2267.7 ± 2.1 | kJ/mol | Ccr | Sunner, 1946 | Reanalyzed by Cox and Pilcher, 1970, Original value = -2268.9 kJ/mol; ALS |
| ΔcH°solid | -2248.9 ± 2.1 | kJ/mol | Ccb | Huffman and Ellis, 1935 | Reanalyzed by Cox and Pilcher, 1970, Original value = -2223.3 ± 2.1 kJ/mol; ALS |
| ΔcH°solid | -2229. ± 3. | kJ/mol | Ccb | Becker and Roth, 1934 | hf_H2SO4.10,000H2O=-900.752 kJ/mol; ALS |
| Quantity | Value | Units | Method | Reference | Comment |
| S°solid,1 bar | 169.9 | J/mol*K | N/A | Huffman and Ellis, 1935, 2 | Extrapolation below 90 K, 48.99 J/mol*K.; DH |
Constant pressure heat capacity of solid
| Cp,solid (J/mol*K) | Temperature (K) | Reference | Comment |
|---|---|---|---|
| 162.3 | 297.6 | Huffman and Ellis, 1935, 2 | T = 85 to 298 K. Value is unsmoothed experimental datum.; DH |
References
Go To: Top, Condensed phase thermochemistry 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]
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]
Notes
Go To: Top, Condensed phase thermochemistry data, 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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