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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Phase change data
Go To: Top, Gas phase ion energetics data, Gas Chromatography, 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:
BS - Robert L. Brown and Stephen E. Stein
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
AC - William E. Acree, Jr., James S. Chickos
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DRB - Donald R. Burgess, Jr.
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
Tboil | 480.2 | K | N/A | Aldrich Chemical Company Inc., 1990 | BS |
Tboil | 477. | K | N/A | Buckingham and Donaghy, 1982 | BS |
Quantity | Value | Units | Method | Reference | Comment |
Tfus | 330.6 | K | N/A | Buckingham and Donaghy, 1982 | BS |
Tfus | 329.15 | K | N/A | Waclawek and Hurwic, 1967 | Uncertainty assigned by TRC = 1.5 K; TRC |
Tfus | 331.65 | K | N/A | Cumper, Ginman, et al., 1963 | Uncertainty assigned by TRC = 0.2 K; TRC |
Quantity | Value | Units | Method | Reference | Comment |
ΔsubH° | 76.5 ± 0.4 | kJ/mol | C | Sabbah and da Silva Eusébio, 1998 | AC |
ΔsubH° | 78.7 ± 0.8 | kJ/mol | C | Bickerton, Pilcher, et al., 1984 | ALS |
ΔsubH° | 78.7 | kJ/mol | N/A | Bickerton, Pilcher, et al., 1984 | DRB |
ΔsubH° | 78.7 ± 0.8 | kJ/mol | C | Bickerton, Pilcher, et al., 1984 | AC |
Reduced pressure boiling point
Tboil (K) | Pressure (bar) | Reference | Comment |
---|---|---|---|
377. to 379. | 0.027 | Buckingham and Donaghy, 1982 | BS |
Enthalpy of fusion
ΔfusH (kJ/mol) | Temperature (K) | Reference | Comment |
---|---|---|---|
15.3 | 331.5 | Sabbah and da Silva Eusébio, 1998 | AC |
Gas phase ion energetics data
Go To: Top, Phase change data, Gas Chromatography, 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 |
Gas Chromatography
Go To: Top, Phase change data, 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 by: NIST Mass Spectrometry Data Center, William E. Wallace, director
Kovats' RI, polar column, isothermal
Column type | Active phase | Temperature (C) | I | Reference | Comment |
---|---|---|---|---|---|
Capillary | PEG-40M | 150. | 1892. | Terenina, Zhuravieva, et al., 1997 | 50. m/0.3 mm/0.4 μm, He |
Packed | PEG-2000 | 179. | 1915. | Anderson, Jurel, et al., 1973 | He, Celite 545 (44-60 mesh); Column length: 3. m |
Packed | PEG-2000 | 180. | 1896. | Anderson, Jurel, et al., 1973 | He, Celite 545 (44-60 mesh); Column length: 3. m |
Packed | PEG-2000 | 200. | 1889. | Anderson, Jurel, et al., 1973 | He, Celite 545 (44-60 mesh); Column length: 3. m |
Packed | PEG-2000 | 200. | 1906. | Anderson, Jurel, et al., 1973 | He, Celite 545 (44-60 mesh); Column length: 3. m |
Van Den Dool and Kratz RI, non-polar column, temperature ramp
Column type | Active phase | I | Reference | Comment |
---|---|---|---|---|
Capillary | DB-5 | 1002. | Premecz and Ford, 1987 | He, 60. C @ 10. min, 10. K/min, 280. C @ 3. min; Column length: 30. m; Column diameter: 0.32 mm |
Van Den Dool and Kratz RI, polar column, temperature ramp
Column type | Active phase | I | Reference | Comment |
---|---|---|---|---|
Capillary | CAM | 1873. | Premecz and Ford, 1987 | He, 60. C @ 5. min, 5. K/min, 240. C @ 21. min; Column length: 15. m; Column diameter: 0.24 mm |
References
Go To: Top, Phase change data, Gas phase ion energetics data, Gas Chromatography, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Aldrich Chemical Company Inc., 1990
Aldrich Chemical Company Inc.,
Catalog Handbook of Fine Chemicals, Aldrich Chemical Company, Inc., Milwaukee WI, 1990, 1. [all data]
Buckingham and Donaghy, 1982
Buckingham, J.; Donaghy, S.M.,
Dictionary of Organic Compounds: Fifth Edition, Chapman and Hall, New York, 1982, 1. [all data]
Waclawek and Hurwic, 1967
Waclawek, Z.; Hurwic, J.,
Dipole moment and spectroscopic studies of the 1,3,5-trinitrobenzene complexes with some pyridine derivatives in nonpolar solvents,
Rocz. Chem., 1967, 41, 1993. [all data]
Cumper, Ginman, et al., 1963
Cumper, C.W.N.; Ginman, R.F.A.; Redford, D.G.; Vogel, A.I.,
Physical Properties and Chemical Constitution. Part XXXVIII. The Electric Dipole Moments of Aminopyridines and Aminoquinolines.,
J. Chem. Soc., 1963, 1963, 1731. [all data]
Sabbah and da Silva Eusébio, 1998
Sabbah, Raphaël; da Silva Eusébio, Maria Ermelinda,
Energétique des liaisons inter- et intramoléculaires dans les trois isomères de l'aminopyridine,
Revue canadienne de chimie, 1998, 76, 1, 18-24, https://doi.org/10.1139/cjc-76-1-18
. [all data]
Bickerton, Pilcher, et al., 1984
Bickerton, J.; Pilcher, G.; Al-Takhin, G.,
Enthalpies of combustion of the three aminopyridines and the three cyanopyridines,
J. Chem. Thermodyn., 1984, 16, 373-378. [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]
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]
Terenina, Zhuravieva, et al., 1997
Terenina, M.B.; Zhuravieva, I.L.; Golovnya, R.V.,
Peculiar features of sorption of positional isomers of formyl-, acetyl-, and aminopyridines in capillary gas-liquid chromatography,
Russ. Chem. Bull. (Engl. Transl.), 1997, 46, 1, 86-89, https://doi.org/10.1007/BF02495353
. [all data]
Anderson, Jurel, et al., 1973
Anderson, A.; Jurel, S.; Shymanska, M.; Golender, L.,
Gas-liquid chromatography of some aliphatic and heterocyclic mono- and pollyfunctional amines. VII. Retention indices of amines in some polar and unpolar stationary phases,
Latv. PSR Zinat. Akad. Vestis Kim. Ser., 1973, 1, 51-63. [all data]
Premecz and Ford, 1987
Premecz, J.E.; Ford, M.E.,
Gas chromatographic separation of substituted pyridines,
J. Chromatogr., 1987, 388, 23-35, https://doi.org/10.1016/S0021-9673(01)94463-2
. [all data]
Notes
Go To: Top, Phase change data, Gas phase ion energetics data, Gas Chromatography, References
- Symbols used in this document:
Tboil Boiling point Tfus Fusion (melting) point ΔfusH Enthalpy of fusion ΔrG° Free energy of reaction at standard conditions ΔrH° Enthalpy of reaction at standard conditions ΔsubH° Enthalpy of sublimation at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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