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, 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) | 947.2 | kJ/mol | N/A | Hunter and Lias, 1998 | HL |
Quantity | Value | Units | Method | Reference | Comment |
Gas basicity | 915.3 | kJ/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° | 1519. ± 10. | kJ/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° | 1518. ± 8.8 | kJ/mol | G+TS | Taft and Bordwell, 1988 | gas phase; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 1489. ± 8.4 | kJ/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° | 1488. ± 8.4 | kJ/mol | IMRE | Taft and Bordwell, 1988 | gas phase; B |
References
Go To: Top, 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.
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]
Notes
Go To: Top, 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
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