2-Aminopyridine
- Formula: C5H6N2
- Molecular weight: 94.1145
- IUPAC Standard InChIKey: ICSNLGPSRYBMBD-UHFFFAOYSA-N
- CAS Registry Number: 504-29-0
- 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. - Other names: 2-Pyridinamine; Pyridine, 2-amino-; α-Aminopyridine; α-Pyridinamine; α-Pyridylamine; β-Pyridylamine; o-Aminopyridine; 2-Pyridylamine; Amino-2 pyridine; 1,2-Dihydro-2-iminopyridine; NSC 431
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Gas phase ion energetics data
Go To: Top, Ion clustering data, Mass spectrum (electron ionization), References, Notes
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
LL - Sharon G. Lias and Joel F. Liebman
LBLHLM - Sharon G. Lias, John E. Bartmess, Joel F. Liebman, John L. Holmes, Rhoda D. Levin, and W. Gary Mallard
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
Proton affinity (review) | 226.4 | kcal/mol | N/A | Hunter and Lias, 1998 | HL |
Quantity | Value | Units | Method | Reference | Comment |
Gas basicity | 218.8 | kcal/mol | N/A | Hunter and Lias, 1998 | HL |
Ionization energy determinations
IE (eV) | Method | Reference | Comment |
---|---|---|---|
8.099 ± 0.003 | PE | Kim, Thantu, et al., 1992 | LL |
8.0 | PE | Guimon, Khayar, et al., 1982 | LBLHLM |
9.3 | CTS | Daisey and Sonnessa, 1972 | LLK |
8.4 | PE | Guimon, Khayar, et al., 1982 | Vertical value; LBLHLM |
8.5 ± 0.1 | EI | Stefanovic and Grutzmacher, 1974 | Vertical value; LLK |
8.34 | PE | Kobayashi and Nagakura, 1974 | Vertical value; LLK |
8.85 ± 0.05 | EI | Gronneberg and Undheim, 1973 | Vertical value; LLK |
De-protonation reactions
C5H5N2- + =
By formula: C5H5N2- + H+ = C5H6N2
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 363.1 ± 2.5 | kcal/mol | TDEq | Meot-ner and Kafafi, 1988 | gas phase; anchored to 88MEO scale, not the "87 acidity scale". The Kiefer, Zhang, et al., 1997 BDE is for ortho.; B |
ΔrH° | 362.8 ± 2.1 | kcal/mol | G+TS | Taft and Bordwell, 1988 | gas phase; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 355.8 ± 2.0 | kcal/mol | TDEq | Meot-ner and Kafafi, 1988 | gas phase; anchored to 88MEO scale, not the "87 acidity scale". The Kiefer, Zhang, et al., 1997 BDE is for ortho.; B |
ΔrG° | 355.6 ± 2.0 | kcal/mol | IMRE | Taft and Bordwell, 1988 | gas phase; B |
Ion clustering data
Go To: Top, Gas phase ion energetics data, Mass spectrum (electron ionization), References, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data compiled by: Robert C. Dunbar
Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. Searches may be limited to ion clustering reactions. A general reaction search form is also available.
Clustering reactions
By formula: K+ + C5H6N2 = (K+ • C5H6N2)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 24.7 ± 0.9 | kcal/mol | CIDT | Rodgers, 2001 |
By formula: Li+ + C5H6N2 = (Li+ • C5H6N2)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 56.8 ± 5.0 | kcal/mol | CIDT | Rodgers, 2001 |
By formula: Na+ + C5H6N2 = (Na+ • C5H6N2)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 35.0 ± 1.4 | kcal/mol | CIDT | Rodgers, 2001 |
Mass spectrum (electron ionization)
Go To: Top, Gas phase ion energetics data, Ion clustering 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 by: NIST Mass Spectrometry Data Center, William E. Wallace, director
Spectrum
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Additional Data
View image of digitized spectrum (can be printed in landscape orientation).
Due to licensing restrictions, this spectrum cannot be downloaded.
Owner | NIST Mass Spectrometry Data Center Collection (C) 2014 copyright by the U.S. Secretary of Commerce on behalf of the United States of America. All rights reserved. |
---|---|
Origin | NIST Mass Spectrometry Data Center, 1998. |
NIST MS number | 290677 |
References
Go To: Top, Gas phase ion energetics data, Ion clustering data, Mass spectrum (electron ionization), Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
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]
Kim, Thantu, et al., 1992
Kim, B.; Thantu, N.; Weber, P.M.,
High resolution photoelectron spectroscopy: The vibrational spectrum of the 2-aminopyridine cation,
J. Chem. Phys., 1992, 97, 5384. [all data]
Guimon, Khayar, et al., 1982
Guimon, C.; Khayar, S.; Pfister-Guillouzo, G.; Claramunt, R.M.; Elguero, J.,
A direct photoelectron spectroscopy study of the 1-azidopyridine pyrolysis,
Spectrosc. Lett., 1982, 15, 435. [all data]
Daisey and Sonnessa, 1972
Daisey, J.M.; Sonnessa, A.J.,
A study of the thermodynamic and spectral properties of molecular complexes of iodine with several aminopyridines,
J. Phys. Chem., 1972, 76, 1895. [all data]
Stefanovic and Grutzmacher, 1974
Stefanovic, D.; Grutzmacher, H.F.,
The ionisation potential of some substituted pyridines,
Org. Mass Spectrom., 1974, 9, 1052. [all data]
Kobayashi and Nagakura, 1974
Kobayashi, T.; Nagakura, S.,
Photoelectron spectra of aminopyridines and cyanopyridines,
J. Electron Spectrosc. Relat. Phenom., 1974, 4, 207. [all data]
Gronneberg and Undheim, 1973
Gronneberg, T.; Undheim, K.,
Mass spectrometry of onium compounds - XV. ionization potentials of amino pyridines,
Tetrahedron Lett., 1973, 3193. [all data]
Meot-ner and Kafafi, 1988
Meot-ner, M.; Kafafi, S.A.,
Carbon Acidities of Aromatic Compounds,
J. Am. Chem. Soc., 1988, 110, 19, 6297, https://doi.org/10.1021/ja00227a003
. [all data]
Kiefer, Zhang, et al., 1997
Kiefer, J.H.; Zhang, Q.; Kern, R.D.; Yao, J.; Jursic, B.,
Pyrolysis of Aromatic Azines: Pyrazine, Pyrimidine, and Pyridine,
J. Phys. Chem. A, 1997, 101, 38, 7061, https://doi.org/10.1021/jp970211z
. [all data]
Taft and Bordwell, 1988
Taft, R.W.; Bordwell, F.G.,
Structural and Solvent Effects Evaluated from Acidities Measured in Dimethyl Sulfoxide and in the Gas Phase,
Acc. Chem. Res., 1988, 21, 12, 463, https://doi.org/10.1021/ar00156a005
. [all data]
Rodgers, 2001
Rodgers, M.T.,
Substituent Effects in the Binding of Alkali Metal Ions to Pyridines, Studied by Threshold Collision-Induced Dissociation and ab Initio Theory: The Aminopyridines,
J. Phys. Chem. A, 2001, 105, 35, 8145, https://doi.org/10.1021/jp011555z
. [all data]
Notes
Go To: Top, Gas phase ion energetics data, Ion clustering data, Mass spectrum (electron ionization), 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
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