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
- IUPAC Standard InChIKey: LEVWYRKDKASIDU-QWWZWVQMSA-N
- CAS Registry Number: 56-89-3
- Chemical structure:
This structure is also available as a 2d Mol file - Stereoisomers:
- 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
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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 | -264.1 | kcal/mol | Ccb | Becker and Roth, 1934 | hf_H2SO4.10,000H2O=-900.752 kJ/mol; ALS |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔcH°solid | -1015.30 ± 0.90 | kcal/mol | Ccr | Sunner, 1946 | Reanalyzed by Cox and Pilcher, 1970, Original value = -1020.37 kcal/mol; ALS |
| ΔcH°solid | -1011.00 ± 0.90 | kcal/mol | Ccb | Huffman and Ellis, 1935 | Reanalyzed by Cox and Pilcher, 1970, Original value = -996.39 ± 0.90 kcal/mol; ALS |
| ΔcH°solid | -1004.1 | kcal/mol | Ccb | Becker and Roth, 1934 | hf_H2SO4.10,000H2O=-900.752 kJ/mol; ALS |
| ΔcH°solid | -993.83 | kcal/mol | Ccb | Emery and Benedict, 1911 | ALS |
| Quantity | Value | Units | Method | Reference | Comment |
| S°solid,1 bar | 67.060 | cal/mol*K | N/A | Hutchens, Cole, et al., 1964 | DH |
| S°solid,1 bar | 68.50 | cal/mol*K | N/A | Huffman and Ellis, 1935, 2 | Extrapolation below 90 K, 79.45 J/mol*K.; DH |
Constant pressure heat capacity of solid
| Cp,solid (cal/mol*K) | Temperature (K) | Reference | Comment |
|---|---|---|---|
| 62.600 | 298.15 | Hutchens, Cole, et al., 1964 | T = 10 to 310 K.; DH |
| 64.20 | 297.3 | 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.
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, 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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