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 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: Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔfH°gas | 28.23 ± 0.26 | kcal/mol | Ccb | Bickerton, Pilcher, et al., 1984 |
Condensed phase 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: Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔfH°solid | 9.4 ± 0.2 | kcal/mol | Ccb | Bickerton, Pilcher, et al., 1984 | |
Quantity | Value | Units | Method | Reference | Comment |
ΔcH°solid | -684.6 ± 0.1 | kcal/mol | Ccb | Bickerton, Pilcher, et al., 1984 |
Phase change 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 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° | 18.3 ± 0.1 | kcal/mol | C | Sabbah and da Silva Eusébio, 1998 | AC |
ΔsubH° | 18.8 ± 0.2 | kcal/mol | C | Bickerton, Pilcher, et al., 1984 | ALS |
ΔsubH° | 18.8 | kcal/mol | N/A | Bickerton, Pilcher, et al., 1984 | DRB |
ΔsubH° | 18.8 ± 0.2 | kcal/mol | C | Bickerton, Pilcher, et al., 1984 | AC |
Reduced pressure boiling point
Tboil (K) | Pressure (atm) | Reference | Comment |
---|---|---|---|
377. to 379. | 0.026 | Buckingham and Donaghy, 1982 | BS |
Enthalpy of fusion
ΔfusH (kcal/mol) | Temperature (K) | Reference | Comment |
---|---|---|---|
3.66 | 331.5 | Sabbah and da Silva Eusébio, 1998 | AC |
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 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
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 |
By formula: Li+ + C5H6N2 = (Li+ • C5H6N2)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 56.8 ± 5.0 | kcal/mol | CIDT | Rodgers, 2001 | RCD |
By formula: Na+ + C5H6N2 = (Na+ • C5H6N2)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 35.0 ± 1.4 | kcal/mol | CIDT | Rodgers, 2001 | RCD |
By formula: K+ + C5H6N2 = (K+ • C5H6N2)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 24.7 ± 0.9 | kcal/mol | CIDT | Rodgers, 2001 | RCD |
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
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 |
IR Spectrum
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Data compiled by: Coblentz Society, Inc.
- SOLID (MINERAL OIL MULL); Not specified, most likely a prism, grating, or hybrid spectrometer.; DIGITIZED BY NIST FROM HARD COPY; 4 cm-1 resolution
- SOLUTION (2% IN CCl4 FOR 3800-1330, 2% IN CS2 FOR 1330-400 CM-1); DOW KBr FOREPRISM-GRATING; DIGITIZED BY NIST FROM HARD COPY (FROM TWO SEGMENTS); 4 cm-1 resolution
Data compiled by: NIST Mass Spectrometry Data Center, William E. Wallace, director
UV/Visible spectrum
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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: Victor Talrose, Eugeny B. Stern, Antonina A. Goncharova, Natalia A. Messineva, Natalia V. Trusova, Margarita V. Efimkina
Spectrum
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Additional Data
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Source | Steck and Ewing, 1948 |
---|---|
Owner | INEP CP RAS, NIST OSRD Collection (C) 2007 copyright by the U.S. Secretary of Commerce on behalf of the United States of America. All rights reserved. |
Origin | INSTITUTE OF ENERGY PROBLEMS OF CHEMICAL PHYSICS, RAS |
Source reference | RAS UV No. 43 |
Instrument | n.i.g. |
Melting point | 57.5 |
Boiling point | 105(20) |
Gas Chromatography
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, Gas phase ion energetics data, IR Spectrum, UV/Visible spectrum, 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, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, Gas phase ion energetics data, IR Spectrum, UV/Visible spectrum, Gas Chromatography, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
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]
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]
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]
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]
Steck and Ewing, 1948
Steck, E.A.; Ewing, G.W.,
Absorption spectra of heterocyclic compounds. II. Amino-derivatives of pyridine, quinoline and isoquinoline,
J. Am. Chem. Soc., 1948, 70, 3397-3406. [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, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, Gas phase ion energetics data, IR Spectrum, UV/Visible spectrum, Gas Chromatography, References
- Symbols used in this document:
Tboil Boiling point Tfus Fusion (melting) point ΔcH°solid Enthalpy of combustion of solid at standard conditions ΔfH°gas Enthalpy of formation of gas at standard conditions ΔfH°solid Enthalpy of formation of solid at standard conditions 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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