2-Aminopyridine

• Formula: C₅H₆N₂
• Molecular weight: 94.1145
• IUPAC Standard InChI: InChI=1S/C5H6N2/c6-5-3-1-2-4-7-5/h1-4H,(H2,6,7) Copy

  
• IUPAC Standard InChIKey: ICSNLGPSRYBMBD-UHFFFAOYSA-N Copy
• 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
• Permanent link for this species. Use this link for bookmarking this species for future reference.
• Information on this page:
  • Gas phase thermochemistry data
  • Condensed phase thermochemistry data
  • Phase change data
  • Reaction thermochemistry data
  • Gas phase ion energetics data
  • Ion clustering data
  • IR Spectrum
  • Mass spectrum (electron ionization)
  • UV/Visible spectrum
  • References
  • Notes
• Other data available:
  • Gas Chromatography
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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

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

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.

Reduced pressure boiling point

Enthalpy of fusion

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

 +  = ( • )

By formula: Li⁺ + C₅H₆N₂ = (Li⁺ • C₅H₆N₂)

 +  = ( • )

By formula: Na⁺ + C₅H₆N₂ = (Na⁺ • C₅H₆N₂)

 +  = ( • )

By formula: K⁺ + C₅H₆N₂ = (K⁺ • C₅H₆N₂)

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

Ionization energy determinations

De-protonation reactions

C₅H₅N₂^- +  =

By formula: C₅H₅N₂^- + H⁺ = C₅H₆N₂

Ion clustering 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: 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)

 +  = ( • )

By formula: Li⁺ + C₅H₆N₂ = (Li⁺ • C₅H₆N₂)

 +  = ( • )

By formula: Na⁺ + C₅H₆N₂ = (Na⁺ • C₅H₆N₂)

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

• gas; HP-GC/MS/IRD

Mass spectrum (electron ionization)

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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: NIST Mass Spectrometry Data Center, William E. Wallace, director

Spectrum

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Additional Data

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

References

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering data, IR Spectrum, Mass spectrum (electron ionization), UV/Visible spectrum, 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]

Notes

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering data, IR Spectrum, Mass spectrum (electron ionization), UV/Visible spectrum, 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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