Pyridine

• Formula: C₅H₅N
• Molecular weight: 79.0999
• IUPAC Standard InChI: InChI=1S/C5H5N/c1-2-4-6-5-3-1/h1-5H Copy

  
• IUPAC Standard InChIKey: JUJWROOIHBZHMG-UHFFFAOYSA-N Copy
• CAS Registry Number: 110-86-1
• 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.
• Isotopologues:
  • Pyridine-D5-
• Other names: Azabenzene; Azine; NCI-C55301; Piridina; Pirydyna; Pyridin; Rcra waste number U196; UN 1282; Pyr; CP 32; NSC 406123
• Permanent link for this species. Use this link for bookmarking this species for future reference.
• Information on this page:
  • Condensed phase thermochemistry data
  • Reaction thermochemistry data
  • Gas phase ion energetics data
  • References
  • Notes
• Other data available:
  • Gas phase thermochemistry data
  • Phase change data
  • Henry's Law data
  • Ion clustering data
  • IR Spectrum
  • Mass spectrum (electron ionization)
  • UV/Visible spectrum
  • Gas Chromatography
• Data at other public NIST sites:
  • Gas Phase Kinetics Database
  • X-ray Photoelectron Spectroscopy Database, version 5.0
• Options:
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Condensed phase thermochemistry data

Go To: Top, Reaction thermochemistry 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 as indicated in comments:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DH - Eugene S. Domalski and Elizabeth D. Hearing

Constant pressure heat capacity of liquid

Reaction thermochemistry data

Go To: Top, Condensed phase thermochemistry 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 as indicated in comments:
B - John E. Bartmess
M - Michael M. Meot-Ner (Mautner) and Sharon G. Lias
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
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

C₅H₄N^- +  =

By formula: C₅H₄N^- + H⁺ = C₅H₅N

C₅H₆N⁺ +  = (C₅H₆N⁺ • )

By formula: C₅H₆N⁺ + C₅H₅N = (C₅H₆N⁺ • C₅H₅N)

 + 3 =

By formula: C₅H₅N + 3H₂ = C₅H₁₁N

 +  = ( • )

By formula: Cl^- + C₅H₅N = (Cl^- • C₅H₅N)

(C₅H₆N⁺ • 2) +  = (C₅H₆N⁺ • 3)

By formula: (C₅H₆N⁺ • 2C₅H₅N) + C₅H₅N = (C₅H₆N⁺ • 3C₅H₅N)

 +  = ( • )

By formula: Li⁺ + C₅H₅N = (Li⁺ • C₅H₅N)

 +  = ( • )

By formula: K⁺ + C₅H₅N = (K⁺ • C₅H₅N)

( • 2) +  = ( • 3)

By formula: (Ag⁺ • 2C₅H₅N) + C₅H₅N = (Ag⁺ • 3C₅H₅N)

( • 3) +  = ( • 4)

By formula: (Ag⁺ • 3C₅H₅N) + C₅H₅N = (Ag⁺ • 4C₅H₅N)

( • ) +  = ( • 2)

By formula: (Cl^- • C₅H₅N) + C₅H₅N = (Cl^- • 2C₅H₅N)

(C₅H₆N⁺ • ) +  = (C₅H₆N⁺ • 2)

By formula: (C₅H₆N⁺ • C₅H₅N) + C₅H₅N = (C₅H₆N⁺ • 2C₅H₅N)

H₂O₃^- +  +  = C₅H₇NO₃^-

By formula: H₂O₃^- + C₅H₅N + H₂O = C₅H₇NO₃^-

 +  = C₅H₅NO₂^-

By formula: O₂^- + C₅H₅N = C₅H₅NO₂^-

 +  = C₅H₅N₂O^-

By formula: NO^- + C₅H₅N = C₅H₅N₂O^-

3 +  = 3 + KClO₃

By formula: 3C₅H₅NO + ClK = 3C₅H₅N + KClO₃

3 +  = 3 + KBrO₃

By formula: 3C₅H₅NO + BrK = 3C₅H₅N + KBrO₃

 +  = ( • )

By formula: Fe⁺ + C₅H₅N = (Fe⁺ • C₅H₅N)

 +  = ( • )

By formula: Cr⁺ + C₅H₅N = (Cr⁺ • C₅H₅N)

 +  = ( • )

By formula: Ti⁺ + C₅H₅N = (Ti⁺ • C₅H₅N)

 +  = ( • )

By formula: Mn⁺ + C₅H₅N = (Mn⁺ • C₅H₅N)

 +  = ( • )

By formula: Sc⁺ + C₅H₅N = (Sc⁺ • C₅H₅N)

 +  = ( • )

By formula: Mg⁺ + C₅H₅N = (Mg⁺ • C₅H₅N)

 +  = ( • )

By formula: V⁺ + C₅H₅N = (V⁺ • C₅H₅N)

 +  = ( • )

By formula: Ni⁺ + C₅H₅N = (Ni⁺ • C₅H₅N)

 +  = ( • )

By formula: Al⁺ + C₅H₅N = (Al⁺ • C₅H₅N)

 +  = ( • )

By formula: Zn⁺ + C₅H₅N = (Zn⁺ • C₅H₅N)

 +  = ( • )

By formula: Co⁺ + C₅H₅N = (Co⁺ • C₅H₅N)

 +  = ( • )

By formula: Cu⁺ + C₅H₅N = (Cu⁺ • C₅H₅N)

 +  = ( • )

By formula: Na⁺ + C₅H₅N = (Na⁺ • C₅H₅N)

Gas phase ion energetics data

Go To: Top, Condensed phase thermochemistry data, Reaction thermochemistry data, 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
L - Sharon G. Lias

Data compiled as indicated in comments:
B - John E. Bartmess
MM - Michael M. Meot-Ner (Mautner)
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
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron

Proton affinity at 298K

Protonation entropy at 298K

Ionization energy determinations

Appearance energy determinations

De-protonation reactions

C₅H₄N^- +  =

By formula: C₅H₄N^- + H⁺ = C₅H₅N

References

Go To: Top, Condensed phase thermochemistry data, Reaction thermochemistry data, 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.

Hubbard, Frow, et al., 1961
Hubbard, W.N.; Frow, F.R.; Waddington, G., The heats of combustion and formation of pyridine and hippuric acid, J. Phys. Chem., 1961, 65, 1326-1328. [all data]

Cox, Challoner, et al., 1954
Cox, J.D.; Challoner, A.R.; Meetham, A.R., The heats of combustion of pyridine and certain of its derivatives, J. Chem. Soc., 1954, 265-271. [all data]

Constam and White, 1903
Constam, E.J.; White, J., Physico-chemical investigations in the pyridine series, Am. Chem. J., 1903, 29, 1-49. [all data]

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Strepikheev, Yu.A.; Baranov, Yu.I.; Burmistrova, O.A., Determination of the heats of combustion and the heat capacities of several mono- and di-isocyanates, Izv. Vyssh. Uchebn. Zaved., Khim. Khim. Tekhnol., 1962, 5, 387-390. [all data]

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McCullough, J.P.; Douslin, D.R.; Messerly, J.F.; Hossenlopp, I.A.; Kincheloe, T.C.; Waddington, G., Pyridine: experimental and calculated chemical thermodynamic properties between 0 and 1500 K., a revised vibrational assignment, J. Am. Chem. Soc., 1957, 79, 4289-4295. [all data]

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Parks, G.S.; Todd, S.S.; Moore, W.A., Thermal data on organic compounds. XVI. Some heat capacity, entropy and free energy data for typical benzene derivatives and heterocyclic compounds, J. Am. Chem. Soc., 1936, 58, 398-401. [all data]

Pearce and Bakke, 1936
Pearce, J.N.; Bakke, H.M., The heat capacity and the free energy of formation of pyridine, Proc. Iowa Acad. Sci., 1936, 43, 171-174. [all data]

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Meot-Ner (Mautner), 1992
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Meot-Ner M.; Sieck, L.W., The Ionic Hydrogen Bond. 1. Sterically Hindered Bonds. Solvation and Clustering of Sterically Hindered Amines and Pyridines, J. Am. Chem. Soc., 1983, 105, 10, 2956, https://doi.org/10.1021/ja00348a005 . [all data]

Holland and Castleman, 1982
Holland, P.M.; Castleman, A.W., The Thermochemical Properties of Gas - Phase Transition Metal Ion Complexes, J. Chem. Phys., 1982, 76, 8, 4195, https://doi.org/10.1063/1.443497 . [all data]

Meot-Ner (Mautner), 1979
Meot-Ner (Mautner), M., Ion Thermochemistry of Low Volatility Compounds in the Gas Phase. II. Intrinsic Basicities and Hydrogen Bonded Dimers of Nitrogen Heterocyclics and Nucleic Bases, J. Am. Chem. Soc., 1979, 101, 9, 2396, https://doi.org/10.1021/ja00503a027 . [all data]

Hales and Herington, 1957
Hales, J.L.; Herington, E.F.G., Equilibrium between pyridine and piperidine, Trans. Faraday Soc., 1957, 53, 616-622. [all data]

Cox and Pilcher, 1970
Cox, J.D.; Pilcher, G., Thermochemistry of Organic and Organometallic Compounds, Academic Press, New York, 1970, 1-636. [all data]

Burrows and King, 1935
Burrows, G.H.; King, L.A., Jr., The free energy change that accompanies hydrogenation of pyridine to piperidine, J. Am. Chem. Soc., 1935, 57, 1789-1791. [all data]

Hiraoka, Mizuse, et al., 1988
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Amunugama and Rodgers, 2000
Amunugama, R.; Rodgers, M.T., Absolute Alkali Metal Ion Binding Affinities of Several Azines Determined by Threshold Collision-Induced Dissociation and Ab Initio Theory, Int. J. Mass Spectrom., 2000, 195/196, 439, https://doi.org/10.1016/S1387-3806(99)00145-1 . [all data]

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Staley, R.H.; Beauchamp, J.L., Intrinsic Acid - Base Properties of Molecules. Binding Energies of Li+ to pi - and n - Donor Bases, J. Am. Chem. Soc., 1975, 97, 20, 5920, https://doi.org/10.1021/ja00853a050 . [all data]

Dzidic and Kebarle, 1970
Dzidic, I.; Kebarle, P., Hydration of the Alkali Ions in the Gas Phase. Enthalpies and Entropies of Reactions M+(H2O)n-1 + H2O = M+(H2O)n, J. Phys. Chem., 1970, 74, 7, 1466, https://doi.org/10.1021/j100702a013 . [all data]

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Davidson, W.R.; Kebarle, P., Binding Energies and Stabilities of Potassium Ion Complexes from Studies of Gas Phase Ion Equilibria K+ + M = K+.M, J. Am. Chem. Soc., 1976, 98, 20, 6133, https://doi.org/10.1021/ja00436a011 . [all data]

Le Barbu, Schiedt, et al., 2002
Le Barbu, K.; Schiedt, J.; Weinkauf, R.; Schlag, E.W.; Nilles, J.M.; Xu, S.J.; Thomas, O.C.; Bowen, K.H., Microsolvation of small anions by aromatic molecules: An exploratory study, J. Chem. Phys., 2002, 116, 22, 9663-9671, https://doi.org/10.1063/1.1475750 . [all data]

Shaofeng and Pilcher, 1988
Shaofeng, L.; Pilcher, G., Enthalpy of formation of pyridine-N-oxide: the dissociation enthalpy of the (N-O) bond, J. Chem. Thermodyn., 1988, 20, 463-465. [all data]

Rodgers, Stanley, et al., 2000
Rodgers, M.T.; Stanley, J.R.; Amunugama, R., Periodic Trends in the Binding of Metal Ions to Pyridine Studied by Threshold Collision-Induced Dissociation and Density Functional Theory, J. Am. Chem. Soc., 2000, 122, 44, 10969, https://doi.org/10.1021/ja0027923 . [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]

Wind, Papp, et al., 2005
Wind, J.J.; Papp, L.; Happel, M.; Hahn, K.; Andriole, E.J.; Poutsma, J.C., Proton Affinity of beta-Oxalylaminoalanine (BOAA): Incorporation of Direct Entropy Correction into the Single-Reference Kinetic Method, J. Am. Soc. Mass Spectrom., 2005, 16, 1151. [all data]

Arimura and Yoshikawa, 1984
Arimura, M.; Yoshikawa, Y., Ionization efficiency and ionization energy of cyclic compounds by electron impact, Mass Spectrosc. (Tokyo), 1984, 32, 375. [all data]

Lifshitz, 1982
Lifshitz, C., Time-dependent mass spectra and breakdown graphs. 2. The kinetic shift in pyridine, J. Phys. Chem., 1982, 86, 606. [all data]

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Kimura, K.; Katsumata, S.; Achiba, Y.; Yamazaki, T.; Iwata, S., Ionization energies, Ab initio assignments, and valence electronic structure for 200 molecules in Handbook of HeI Photoelectron Spectra of Fundamental Organic Compounds, Japan Scientific Soc. Press, Tokyo, 1981. [all data]

Utsunomiya, Kobayashi, et al., 1978
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Eland, Berkowitz, et al., 1978
Eland, J.H.D.; Berkowitz, J.; Schulte, H.; Frey, R., Rates of unimolecular pyridine ion decay and the heat of formation of C₄H₄⁺, Int. J. Mass Spectrom. Ion Phys., 1978, 28, 297. [all data]

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Distefano, Foffani, et al., 1971, 2
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Rosenstock, McCulloh, et al., 1977
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Beynon, Hopkinson, et al., 1969
Beynon, J.H.; Hopkinson, J.A.; Lester, G.R., Mass spectrometry-the appearance potentials of "meta-stable peaks" in some aromatic nitro compounds - a chemical reaction in the mass spectrometer, Intern. J. Mass Spectrom. Ion Phys., 1969, 2, 291. [all data]

Notes

Go To: Top, Condensed phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, References

• Symbols used in this document:
  

  AE	Appearance energy
  Cp,liquid	Constant pressure heat capacity of liquid
  IE (evaluated)	Recommended ionization energy
  S°liquid	Entropy of liquid at standard conditions
  ΔcH°liquid	Enthalpy of combustion of liquid at standard conditions
  ΔfH°liquid	Enthalpy of formation of liquid at standard conditions
  ΔrG°	Free energy of reaction at standard conditions
  ΔrH°	Enthalpy of reaction at standard conditions
  ΔrS°	Entropy of reaction at standard conditions

• Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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