Pyrrole

• Formula: C₄H₅N
• Molecular weight: 67.0892
• IUPAC Standard InChI: InChI=1S/C4H5N/c1-2-4-5-3-1/h1-5H Copy

  
• IUPAC Standard InChIKey: KAESVJOAVNADME-UHFFFAOYSA-N Copy
• CAS Registry Number: 109-97-7
• 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: 1H-Pyrrole; Azole; Divinylenimine; Imidole; Monopyrrole; Pyrrol; 1-Aza-2,4-cyclopentadiene; Divinyleneimine; Parzate; NSC 62777
• 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
  • Reaction thermochemistry data
  • Gas phase ion energetics data
  • References
  • Notes
• Other data available:
  • Phase change 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
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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 as indicated in comments:
DRB - Donald R. Burgess, Jr.
ALS - 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 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

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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
M - Michael M. Meot-Ner (Mautner) and Sharon G. Lias
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

 +  =

By formula: C₄H₄N^- + H⁺ = C₄H₅N

CN^- +  = (CN^- • )

By formula: CN^- + C₄H₅N = (CN^- • C₄H₅N)

 +  = ( • )

By formula: F^- + C₄H₅N = (F^- • C₄H₅N)

 +  = ( • )

By formula: Cl^- + C₄H₅N = (Cl^- • C₄H₅N)

Free energy of reaction

HS^- +  = (HS^- • )

By formula: HS^- + C₄H₅N = (HS^- • C₄H₅N)

 +  = ( • )

By formula: C₄H₄N^- + C₄H₅N = (C₄H₄N^- • C₄H₅N)

 +  = ( • )

By formula: C₂H₃O₂^- + C₄H₅N = (C₂H₃O₂^- • C₄H₅N)

(C₄H₅N⁺ • ) +  = (C₄H₅N⁺ • 2)

By formula: (C₄H₅N⁺ • C₄H₅N) + C₄H₅N = (C₄H₅N⁺ • 2C₄H₅N)

Bond type: Charge transfer bond (positive ion)

C₄H₅N⁺ +  = (C₄H₅N⁺ • )

By formula: C₄H₅N⁺ + C₄H₅N = (C₄H₅N⁺ • C₄H₅N)

Bond type: Charge transfer bond (positive ion)

(C₄H₆N⁺ • ) +  = (C₄H₆N⁺ • 2)

By formula: (C₄H₆N⁺ • C₄H₅N) + C₄H₅N = (C₄H₆N⁺ • 2C₄H₅N)

( • ) +  = ( • 2)

By formula: (C₄H₄N^- • C₄H₅N) + C₄H₅N = (C₄H₄N^- • 2C₄H₅N)

C₄H₆N⁺ +  = (C₄H₆N⁺ • )

By formula: C₄H₆N⁺ + C₄H₅N = (C₄H₆N⁺ • C₄H₅N)

( • ) +  = ( • 2)

By formula: (C₂H₃O₂^- • C₄H₅N) + C₄H₅N = (C₂H₃O₂^- • 2C₄H₅N)

CH₆N⁺ +  = (CH₆N⁺ • )

By formula: CH₆N⁺ + C₄H₅N = (CH₆N⁺ • C₄H₅N)

 +  = ( • )

By formula: C₆H₁₁NO₃ + C₄H₅N = (C₆H₁₁NO₃ • C₄H₅N)

( • ) +  = ( • 2)

By formula: (Fe⁺ • C₄H₅N) + C₄H₅N = (Fe⁺ • 2C₄H₅N)

( • ) +  = ( • 2)

By formula: (Cr⁺ • C₄H₅N) + C₄H₅N = (Cr⁺ • 2C₄H₅N)

( • ) +  = ( • 2)

By formula: (Mn⁺ • C₄H₅N) + C₄H₅N = (Mn⁺ • 2C₄H₅N)

( • ) +  = ( • 2)

By formula: (Ni⁺ • C₄H₅N) + C₄H₅N = (Ni⁺ • 2C₄H₅N)

( • ) +  = ( • 2)

By formula: (Co⁺ • C₄H₅N) + C₄H₅N = (Co⁺ • 2C₄H₅N)

( • ) +  = ( • 2)

By formula: (Cu⁺ • C₄H₅N) + C₄H₅N = (Cu⁺ • 2C₄H₅N)

 +  = ( • )

By formula: Li⁺ + C₄H₅N = (Li⁺ • C₄H₅N)

 +  = ( • )

By formula: Na⁺ + C₄H₅N = (Na⁺ • C₄H₅N)

 +  = ( • )

By formula: K⁺ + C₄H₅N = (K⁺ • C₄H₅N)

 +  = ( • )

By formula: V⁺ + C₄H₅N = (V⁺ • C₄H₅N)

 +  = ( • )

By formula: Ni⁺ + C₄H₅N = (Ni⁺ • C₄H₅N)

 +  = ( • )

By formula: W⁺ + C₄H₅N = (W⁺ • C₄H₅N)

 +  = ( • )

By formula: Co⁺ + C₄H₅N = (Co⁺ • C₄H₅N)

 +  = ( • )

By formula: Mo⁺ + C₄H₅N = (Mo⁺ • C₄H₅N)

 +  = ( • )

By formula: Fe⁺ + C₄H₅N = (Fe⁺ • C₄H₅N)

 +  = ( • )

By formula: Cr⁺ + C₄H₅N = (Cr⁺ • C₄H₅N)

 +  = ( • )

By formula: Mn⁺ + C₄H₅N = (Mn⁺ • C₄H₅N)

 +  = ( • )

By formula: Mg⁺ + C₄H₅N = (Mg⁺ • C₄H₅N)

 +  = ( • )

By formula: Al⁺ + C₄H₅N = (Al⁺ • C₄H₅N)

 +  = ( • )

By formula: Cu⁺ + C₄H₅N = (Cu⁺ • C₄H₅N)

Gas phase ion energetics data

Go To: Top, Gas phase thermochemistry data, 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
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

Ionization energy determinations

Appearance energy determinations

De-protonation reactions

 +  =

By formula: C₄H₄N^- + H⁺ = C₄H₅N

References

Go To: Top, Gas phase thermochemistry data, 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.

Zaheeruddin and Lodhi, 1991
Zaheeruddin, M.; Lodhi, Z.H., Enthalpies of formation of some cyclic compounds, Phys. Chem. (Peshawar Pak.), 1991, 10, 111-118. [all data]

Scott, Berg, et al., 1967
Scott, D.W.; Berg, W.T.; Hossenlopp, I.A.; Hubbard, W.N.; Messerly, J.F.; Todd, S.S.; Douslin, D.R.; McCullough, J.P.; Waddington, G., Pyrrole: Chemical thermodynamic properties, J. Phys. Chem., 1967, 71, 2263-2270. [all data]

Zimmerman and Geisenfelder, 1961
Zimmerman, H.; Geisenfelder, H., Uber die Mesomerieenergie von Azolen, Z. Electrochem., 1961, 65, 368-371. [all data]

Gianola, Ichino, et al., 2004
Gianola, A.J.; Ichino, T.; Hoenigman, R.L.; Kato, S.; Bierbaum, V.M.; Lineberger, W.C., Thermochemistry and electronic structure of the pyrrolyl radical, J. Phys. Chem. A, 2004, 108, 46, 10326-10335, https://doi.org/10.1021/jp047790+ . [all data]

Bartmess, Scott, et al., 1979
Bartmess, J.E.; Scott, J.A.; McIver, R.T., Jr., The gas phase acidity scale from methanol to phenol, J. Am. Chem. Soc., 1979, 101, 6047. [all data]

Cumming and Kebarle, 1978
Cumming, J.B.; Kebarle, P., Summary of gas phase measurements involving acids AH. Entropy changes in proton transfer reactions involving negative ions. Bond dissociation energies D(A-H) and electron affinities EA(A), Can. J. Chem., 1978, 56, 1. [all data]

Muftakhov, Vasil'ev, et al., 1999
Muftakhov, M.V.; Vasil'ev, Y.V.; Khatymov, R.V.; Mazunov, V.A.; Takhistov, V.V.; Travkin, O.V.; Yakovleva, E.V., Thermochemistry of negatively charged ions. II. Energetics of formation of negative ions from acridanone and some of its derivatives, Rapid Commun. Mass Spectrom., 1999, 13, 10, 912-923, https://doi.org/10.1002/(SICI)1097-0231(19990530)13:10<912::AID-RCM585>3.0.CO;2-W . [all data]

Meot-ner, 1988
Meot-ner, M., Ionic Hydrogen Bond and Ion Solvation. ₆. Interaction Energies of the Acetate Ion with Organic Molecules. Comparison of CH₃COO^- with Cl^-, CN^-, and SH^-, J. Am. Chem. Soc., 1988, 110, 12, 3854, https://doi.org/10.1021/ja00220a022 . [all data]

Larson and McMahon, 1987
Larson, J.W.; McMahon, T.B., Hydrogen bonding in gas phase anions. The energetics of interaction between cyanide ion and bronsted acids, J. Am. Chem. Soc., 1987, 109, 6230. [all data]

Payzant, Yamdagni, et al., 1971
Payzant, J.D.; Yamdagni, R.; Kebarle, P., Hydration of CN-, NO₂-, NO₃-, and HO- in the gas phase, Can. J. Chem., 1971, 49, 3308. [all data]

Larson and McMahon, 1983
Larson, J.W.; McMahon, T.B., Strong hydrogen bonding in gas-phase anions. An ion cyclotron resonance determination of fluoride binding energetics to bronsted acids from gas-phase fluoride exchange equilibria measurements, J. Am. Chem. Soc., 1983, 105, 2944. [all data]

Arshadi, Yamdagni, et al., 1970
Arshadi, M.; Yamdagni, R.; Kebarle, P., Hydration of Halide Negative Ions in the Gas Phase. II. Comparison of Hydration Energies for the Alkali Positive and Halide Negative Ions, J. Phys. Chem., 1970, 74, 7, 1475, https://doi.org/10.1021/j100702a014 . [all data]

Larson and McMahon, 1984
Larson, J.W.; McMahon, T.B., Hydrogen bonding in gas phase anions. An experimental investigation of the interaction between chloride ion and bronsted acids from ICR chloride exchange equilibria, J. Am. Chem. Soc., 1984, 106, 517. [all data]

French, Ikuta, et al., 1982
French, M.A.; Ikuta, S.; Kebarle, P., Hydrogen bonding of O-H and C-H hydrogen donors to Cl^-. Results from mass spectrometric measurement of the ion-molecule equilibria RH + Cl^- = RHCl^-, Can. J. Chem., 1982, 60, 1907. [all data]

Meot-ner, 1988, 2
Meot-ner, M., The Ionic Hydrogen Bond and Solvation. 7. Interaction Energies of Carbanions with Solvent Molecules, J. Am. Chem. Soc., 1988, 110, 12, 3858, https://doi.org/10.1021/ja00220a022 . [all data]

Hiraoka, Takimoto, et al., 1987
Hiraoka, K.; Takimoto, H.; Yamabe, S., Stabilities and Structures in Cluster Ions of Five-Membered Heterocyclic Compounds Containing O, N and S Atoms, J. Am. Chem. Soc., 1987, 109, 24, 7346, https://doi.org/10.1021/ja00258a018 . [all data]

Deakyne and Meot-Ner (Mautner), 1985
Deakyne, C.A.; Meot-Ner (Mautner), M., Unconventional Ionic Hydrogen Bonds. 2. NH+ pi. Complexes of Onium Ions with Olefins and Benzene Derivatives, J. Am. Chem. Soc., 1985, 107, 2, 474, https://doi.org/10.1021/ja00288a034 . [all data]

Meot-Ner (Mautner), 1988
Meot-Ner (Mautner), M., Models for Strong Interactions in Proteins and Enzymes. 2. Interactions of Ions with the Peptide Link and Imidazole, J. Am. Chem. Soc., 1988, 110, 10, 3075, https://doi.org/10.1021/ja00218a014 . [all data]

Gapeev and Yang, 2000
Gapeev, A.; Yang, C.-N., Binding Energies of Gas-Phase Ions with Pyrrole. Experimental and Quantum Chemical Results, J. Phys. Chem. A, 2000, 104, 14, 3246, https://doi.org/10.1021/jp992627d . [all data]

Huang and Rodgers, 2002
Huang, H.; Rodgers, M.T., Sigma versus Pi interactions in alkali metal ion binding to azoles: Threshold collision-induced dissociation and ab initio theory studies, J. Phys. Chem. A, 2002, 106, 16, 4277, https://doi.org/10.1021/jp013630b . [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]

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Klasinc, L.; Sabljic, A.; Kluge, G.; Rieger, J.; Scholz, M., Chemistry of excited states. Part 13. Assignment of lowest .PI.-ionizations in photoelectron spectra of thiophen, furan, and pyrrole, J. Chem. Soc. Perkin Trans. 2, 1982, 539. [all data]

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Galasso, V.; Klasinc, L.; Sabluic, A.; Trinajstic, N.; Pappalardo, G.C.; Steglich, W., Conformation and photoelectron spectra of 2-(2-Furyl)pyrrole and 2-(2-tThienyl)pyrrole, J. Chem. Soc. Perkin Trans. 2, 1981, 127. [all data]

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Williamson, A.D.; Compton, R.N.; Eland, J.H.D., Accurate photoionization thresholds by multiphoton ionization: Pyrrole, J. Chem. Phys., 1979, 70, 590. [all data]

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Sakurai, H.; Jennings, K.R., A study of the structures of decomposing and non-decomposing [C₄H₅N]⁺ ions formed from different neutral species, Org. Mass Spectrom., 1981, 16, 393. [all data]

Notes

Go To: Top, Gas phase thermochemistry data, 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
  T	Temperature
  ΔcH°liquid	Enthalpy of combustion of liquid at standard conditions
  ΔfH°gas	Enthalpy of formation of gas 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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