Molecular properties
- Formula
- C3H7NO2S
- Molar mass
- 121.16 g·mol−1
- Exact mass
- 121.0197 Da
- 1
- 3
- 4
- 64.30 Ų
- -2.5 (PubChem computed XLogP3-AA descriptor)
- CAS
- 52-90-4
- PubChem CID
- 5862
Molecule record
cysteine
C3H7NO2S
121.16 g/mol
Interactions
- Polarity
- Often polar; exact polarity depends on size, substitution, and ionization state.
- Acid-base behavior
- Review ionizable groups and pKa data where available; ChemForge does not infer definitive acid-base state from identity alone.
- Intermolecular forces
- Assess dispersion, dipole interactions, hydrogen bonding, and ionic character from the functional groups shown.
Functional groups
Alcohol
Amine
Carboxylic acid
Physical properties
| Property | Value | Conditions | Source |
|---|---|---|---|
| Logp | -2.5 | PubChem computed XLogP3-AA descriptor | PubChem(link only) |
Common names and synonyms
- (2R)-2-amino-3-sulfanylpropanoic acid
- (R)-2-Amino-3-mercaptopropanoic acid
- 2-Amino-3-mercaptopropionic acid
- 52-90-4
- Cisteinum
- Cisteinum [Latin]
- Cystein
- Cysteinum
Show all 23 synonyms
- FEMA No. 3263
- FREE CYSTEINE
- Half cystine
- Half-cystine
- L-(+)-Cysteine
- L-2-Amino-3-mercaptopropionic acid
- L-Alanine, 3-mercapto-
- L-Cys
- L-Cystein
- L-cysteine
- NSC-8746
- Thioserine
- alpha-Amino-beta-thiolpropionic acid
- beta-Mercaptoalanine
- cisteina
Structure identifiers
- Canonical SMILES
- C([C@@H](C(=O)O)N)S
- Isomeric SMILES
- C([C@@H](C(=O)O)N)S
- InChI
- InChI=1S/C3H7NO2S/c4-2(1-7)3(5)6/h2,7H,1,4H2,(H,5,6)/t2-/m0/s1
- InChIKey
- XUJNEKJLAYXESH-REOHCLBHSA-N
- PubChem CID
- 5862
Spectroscopy
Tabs appear only for spectra stored with clear provenance.
Simulated FTIR trace
Predicted FTIR / %T
4 cm-1 resolution / deterministic instrument profile
Hover for cursor
Peak assignments
3350 cm−1broad O-H (simulated)
3000 cm−1broad acid O-H (simulated)
1710 cm−1C=O acid (simulated)
2960 cm−1sp3 C-H (simulated)
Simulated NMR
On-demand educational prediction for cysteine; not experimental data.
Simulated EI mass spectrum
On-demand educational fragmentation for cysteine; not experimental data.
Sources
Molecule identity
Retrieved 8/7/2026. Reuse status is summarized by the badge; open the source for full details.
simulated IR
ChemForge original educational simulation.