Tryptophan
- Formula: C11H12N2O2
- Molecular weight: 204.2252
- IUPAC Standard InChI: InChI=1S/C11H12N2O2/c12-9(11(14)15)5-7-6-13-10-4-2-1-3-8(7)10/h1-4,6,9,13H,5,12H2,(H,14,15)
- IUPAC Standard InChIKey: QIVBCDIJIAJPQS-UHFFFAOYSA-N
- CAS Registry Number: 54-12-6
- 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: DL-Tryptophan; DL-α-Amino-3-indolepropionic acid; DL-Trytophan; DL-Trytophane; Racemic Tryptophan; Tryptophan, DL-; Tryptophane; (.+/-.)-Tryptophan; NSC 13118; DL-Tryptophane
- Permanent link for this species. Use this link for bookmarking this species for future reference.
- Information on this page:
- Other data available:
- Options:
Reaction thermochemistry data
Go To: Top, Gas phase ion energetics 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 as indicated in comments:
B - John E. Bartmess
RCD - Robert C. Dunbar
Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. A general reaction search form is also available. Future versions of this site may rely on reaction search pages in place of the enumerated reaction displays seen below.
Individual Reactions
+
=
By formula: C11H11N2O2- + H+ = C11H12N2O2
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 339.6 ± 2.2 | kcal/mol | CIDC | Jones, Bernier, et al., 2007 | gas phase; B |
| ΔrH° | 336.7 ± 3.1 | kcal/mol | G+TS | O'Hair, Bowie, et al., 1992 | gas phase; B |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔrG° | 329.9 ± 3.0 | kcal/mol | CIDC | O'Hair, Bowie, et al., 1992 | gas phase; B |
+
= (
•
)
By formula: Na+ + C11H12N2O2 = (Na+ • C11H12N2O2)
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 49.0 ± 3.0 | kcal/mol | IMRE | Gapeev and Dunbar, 2003 | Anchor glycine=38.5+-2.6; RCD |
| ΔrH° | 50.2 | kcal/mol | CIDC | Kish, Ohanessian, et al., 2003 | Anchor alanine=39.89; RCD |
Gas phase ion energetics data
Go To: Top, Reaction 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 as indicated in comments:
B - John E. Bartmess
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
Ionization energy determinations
| IE (eV) | Method | Reference | Comment |
|---|---|---|---|
| 8.43 | CTS | Slifkin and Allison, 1967 | RDSH |
| ≤7.5 | EI | Akopyan and Loginov, 1967 | RDSH |
De-protonation reactions
+
=
By formula: C11H11N2O2- + H+ = C11H12N2O2
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 339.6 ± 2.2 | kcal/mol | CIDC | Jones, Bernier, et al., 2007 | gas phase; B |
| ΔrH° | 336.7 ± 3.1 | kcal/mol | G+TS | O'Hair, Bowie, et al., 1992 | gas phase; B |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔrG° | 329.9 ± 3.0 | kcal/mol | CIDC | O'Hair, Bowie, et al., 1992 | gas phase; B |
References
Go To: Top, Reaction thermochemistry data, Gas phase ion energetics data, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Jones, Bernier, et al., 2007
Jones, C.M.; Bernier, M.; Carson, E.; Colyer, K.E.; Metz, R.; Pawlow, A.; Wischow, E.D.; Webb, I.; Andriole, E.J.; Poutsma, J.C.,
Gas-phase Acities of the 20 Protein Amino Acids,
Int. J. Mass Spectrom., 2007, 267, 1-3, 54-62, https://doi.org/10.1016/j.ijms.2007.02.018
. [all data]
O'Hair, Bowie, et al., 1992
O'Hair, R.J.; Bowie, J.H.; Gronert, S.,
Gas Phase Acidity of the alpha-Amino Acids,
Int. J. Mass Spectrom. Ion Proc., 1992, 117, 23, https://doi.org/10.1016/0168-1176(92)80083-D
. [all data]
Gapeev and Dunbar, 2003
Gapeev, A.; Dunbar, R.C.,
Na+ Affinities of Gas-Phase Amino Acids by Ligand Exchange Equilibrium,
Int. J. Mass Spectrom., 2003, 228, 2-3, 825, https://doi.org/10.1016/S1387-3806(03)00242-2
. [all data]
Kish, Ohanessian, et al., 2003
Kish, M.M.; Ohanessian, G.; Wesdemiotis, C.,
The Na+ affinities of a-amino acids: side-chain substituent effects,
Int. J. Mass Spectrom., 2003, 227, 3, 509, https://doi.org/10.1016/S1387-3806(03)00082-4
. [all data]
Slifkin and Allison, 1967
Slifkin, M.A.; Allison, A.C.,
Measurement of ionization potentials from contact charge transfer spectra,
Nature, 1967, 215, 949. [all data]
Akopyan and Loginov, 1967
Akopyan, M.E.; Loginov, Yy.V.,
Mass-spectrometric study of the phoionization of free α-aminoacids,
High Energy Chem., 1967, 1, 83, In original 97. [all data]
Notes
Go To: Top, Reaction thermochemistry data, Gas phase ion energetics data, References
- Symbols used in this document:
ΔrG° Free energy of reaction at standard conditions ΔrH° Enthalpy of reaction 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.