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:
  • Gas phase thermochemistry data
  • Reaction thermochemistry data
  • Gas phase ion energetics data
  • Ion clustering data
  • IR Spectrum
  • References
  • Notes
• Other data available:
  • Condensed phase thermochemistry data
  • Phase change data
  • Henry's Law data
  • 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:
  • Switch to SI units

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• NIST / TRC Web Thermo Tables, professional edition (thermophysical and thermochemical data)

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Gas phase thermochemistry data

Go To: Top, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering data, IR 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 as indicated in comments:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DRB - Donald R. Burgess, Jr.

Reaction thermochemistry data

Go To: Top, Gas phase thermochemistry data, Gas phase ion energetics data, Ion clustering data, IR 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 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, Gas phase thermochemistry data, Reaction thermochemistry data, Ion clustering data, IR Spectrum, 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

Ion clustering data

Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, IR 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 as indicated in comments:
M - Michael M. Meot-Ner (Mautner) and Sharon G. Lias
RCD - Robert C. Dunbar
B - John E. Bartmess

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

( • 2) +  = ( • 3)

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

( • 3) +  = ( • 4)

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

 +  = ( • )

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

C₅H₆N⁺ +  = (C₅H₆N⁺ • )

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

(C₅H₆N⁺ • ) +  = (C₅H₆N⁺ • 2)

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

(C₅H₆N⁺ • 2) +  = (C₅H₆N⁺ • 3)

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

 +  = ( • )

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

( • ) +  = ( • 2)

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

 +  = ( • )

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

 +  = ( • )

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

 +  = ( • )

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

 +  = ( • )

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

H₂O₃^- +  +  = C₅H₇NO₃^-

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

 +  = ( • )

By formula: K⁺ + C₅H₅N = (K⁺ • C₅H₅N)

 +  = ( • )

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

 +  = ( • )

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

 +  = ( • )

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

 +  = C₅H₅N₂O^-

By formula: NO^- + C₅H₅N = C₅H₅N₂O^-

 +  = ( • )

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

 +  = ( • )

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

 +  = C₅H₅NO₂^-

By formula: O₂^- + C₅H₅N = C₅H₅NO₂^-

 +  = ( • )

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

 +  = ( • )

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

 +  = ( • )

By formula: V⁺ + C₅H₅N = (V⁺ • C₅H₅N)

 +  = ( • )

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

IR Spectrum

Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering data, References, Notes

Data compiled by: Coblentz Society, Inc.

• GAS (15 mmHg, N2 ADDED, TOTAL PRESSURE 600 mmHg); DOW KBr FOREPRISM-GRATING; DIGITIZED BY COBLENTZ SOCIETY (BATCH II) FROM HARD COPY; 2 cm^-1 resolution
• SOLUTION (10% IN CCl4 FOR 3800-1300, 10% IN CS2 FOR 1300-650, 10% IN CCl4 FOR 650-250 CM^-1) VERSUS SOLVENT; PERKIN-ELMER 521 (GRATING); DIGITIZED BY NIST FROM HARD COPY (FROM TWO SEGMENTS); 4 cm^-1 resolution
• VAPOR (0.5 MICROLITER AT 150 C); NICOLET FTIR; DIGITIZED BY NIST FROM HARD COPY (FROM TWO SEGMENTS); 4 CM^-1 cm^-1 resolution

Data compiled by: Tanya L. Myers, Russell G. Tonkyn, Ashley M. Oeck, Tyler O. Danby, John S. Loring, Matthew S. Taubman, Stephen W. Sharpe, Jerome C. Birnbaum, and Timothy J. Johnson

• liquid; Bruker Tensor 27 FTIR; 0.4821395 cm^-1 resolution

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

• gas

References

Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering data, IR Spectrum, Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

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Cox, Challoner, et al., 1954
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Klasinc, Novak, et al., 1978
Klasinc, L.; Novak, I.; Scholz, M.; Kluge, G., Photoelektronenspektren substituierter Pyridine und Benzole und ihre Interpretation durch die CNDO/SWW-Methode, Croat. Chem. Acta, 1978, 51, 43. [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]

Batich, Heilbronner, et al., 1973
Batich, C.; Heilbronner, E.; Hornung, V.; Ashe, A.J.; Clark, D.T.; Cobley, U.T.; Kilcast, D.; Scanlan, I., Photoelectron spectra of phosphabenzen, arsabenzene, and stibabenzene, J. Am. Chem. Soc., 1973, 95, 928. [all data]

Heilbronner, Hornung, et al., 1972
Heilbronner, E.; Hornung, V.; Pinkerton, F.H.; Thames, S.F., 31. Photoelectron spectra of azabenzenes and azanaphthalenes: III. The orbital sequence in methyl- and trimethylsilyl- substituted pyridines, Helv. Chim. Acta, 1972, 55, 289. [all data]

Gleiter, Heilbronner, et al., 1970
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Momigny, Urbain, et al., 1965
Momigny, J.; Urbain, J.; Wankenne, H., Les effets de l'impact electronique sur la pyridine et les diazines isomeres, Bull. Soc. Roy. Sci. Liege, 1965, 34, 337. [all data]

Lifshitz and Malinovich, 1984
Lifshitz, C.; Malinovich, Y., Time resolved photoionization mass spectrometry in the millisecond range, Int. J. Mass Spectrom. Ion Processes, 1984, 60, 99. [all data]

Burgers and Holmes, 1984
Burgers, P.C.; Holmes, J.L., Fragmentation rate constants and appearance energies for reactions having a large kinetic shift and the energy partitioning in their metastable decomposition, Int. J. Mass Spectrom. Ion Processes, 1984, 58, 15. [all data]

Rosenstock, Stockbauer, et al., 1981
Rosenstock, H.M.; Stockbauer, R.; Parr, A.C., Unimolecular kinetis of pyridine ion fragmentation, Int. J. Mass Spectrom. Ion Phys., 1981, 38, 323. [all data]

Rosenstock, McCulloh, et al., 1977
Rosenstock, H.M.; McCulloh, K.E.; Lossing, F.P., On the mechanisms of C₆H₆ ionization fragmentation, Int. J. Mass Spectrom. Ion Phys., 1977, 25, 327. [all data]

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

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• Symbols used in this document:
  

  AE	Appearance energy
  IE (evaluated)	Recommended ionization energy
  ΔfH°gas	Enthalpy of formation of gas 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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