Leucine

• Formula: C₆H₁₃NO₂
• Molecular weight: 131.1729
• IUPAC Standard InChI: InChI=1S/C6H13NO2/c1-4(2)3-5(7)6(8)9/h4-5H,3,7H2,1-2H3,(H,8,9)/t5-/m1/s1 Copy

  
• IUPAC Standard InChIKey: ROHFNLRQFUQHCH-RXMQYKEDSA-N Copy
• CAS Registry Number: 61-90-5
• Chemical structure:
  This structure is also available as a 2d Mol file
• Stereoisomers:
  • Leucine
  • D-Leucine
  • DL-Leucine
• Other names: L-Leucine; Leucine, L-; L-α-Aminoisocaproic acid; α-Amino-γ-methylvaleric acid; (S)-(+)-Leucine; L-(+)-Leucine; Leu; Pentanoic acid, 2-amino-4-methyl-, (S)-; 2-Amino-4-methylpentanoic acid, (L)-; 2-Amino-4-methylvaleric acid, (L)-; iso-C4H9CH(NH2)COOH; L-(-)-2-Amino-4-methylpentanoic acid; Norvaline, 4-methyl-, (L)-; Valeric acid, 2-amino-4-methyl-, (S)-; Leucin; (S)-2-Amino-4-methylpentanoic acid; (S)-Leucine; (S)-2-Amino-4-methylvaleric acid; L-Norvaline, 4-methyl-; NSC 46709
• Permanent link for this species. Use this link for bookmarking this species for future reference.
• Information on this page:
  • Reaction thermochemistry data
  • Gas phase ion energetics data
  • References
  • Notes
• Other data available:
  • Gas phase thermochemistry data
  • Condensed phase thermochemistry data
  • Phase change data
  • IR Spectrum
  • Mass spectrum (electron ionization)
• Data at other public NIST sites:
  • X-ray Photoelectron Spectroscopy Database, version 5.0
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Reaction thermochemistry data

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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data compiled by: John E. Bartmess

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

C₆H₁₂NO₂^- +  =

By formula: C₆H₁₂NO₂^- + H⁺ = C₆H₁₃NO₂

Gas phase ion energetics data

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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data evaluated as indicated in comments:
HL - Edward P. Hunter and Sharon G. Lias

Data compiled as indicated in comments:
B - John E. Bartmess
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron

Ionization energy determinations

Appearance energy determinations

De-protonation reactions

C₆H₁₂NO₂^- +  =

By formula: C₆H₁₂NO₂^- + H⁺ = C₆H₁₃NO₂

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]

Hunter and Lias, 1998
Hunter, E.P.; Lias, S.G., Evaluated Gas Phase Basicities and Proton Affinities of Molecules: An Update, J. Phys. Chem. Ref. Data, 1998, 27, 3, 413-656, https://doi.org/10.1063/1.556018 . [all data]

Klasinc, 1976
Klasinc, L., Application of photoelectron spectroscopy to biologically active molecules and their constituent parts, J. Electron Spectrosc. Relat. Phenom., 1976, 8, 161. [all data]

Junk and Svec, 1963
Junk, G.; Svec, H., The mass spectra of the α-amino acids, J. Am. Chem. Soc., 1963, 85, 839. [all data]

Notes

Go To: Top, Reaction thermochemistry data, Gas phase ion energetics data, References

• Symbols used in this document:
  

  AE	Appearance energy
  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
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