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
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• Information on this page:
  • Gas phase ion energetics data
  • References
  • Notes
• Other data available:
  • Gas phase thermochemistry data
  • Condensed phase thermochemistry data
  • Phase change data
  • Reaction thermochemistry 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 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
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 ion energetics data, Notes

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

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]

Klasinc, Sabljic, et al., 1982
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]

Galasso, Klasinc, et al., 1981
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]

Willett and Baer, 1980
Willett, G.D.; Baer, T., Thermochemistry and dissociation dynamics of state-selected C₄H₄X ions. 3. C₄H₅N⁺, J. Am. Chem. Soc., 1980, 102, 6774. [all data]

Tedder and Vidaud, 1980
Tedder, J.M.; Vidaud, P.H., Charge exchange mass spectra of thiophene, pyrrole and furan, J. Chem. Soc. Faraday Trans. 2, 1980, 76, 1516. [all data]

Cooper, Williamson, et al., 1980
Cooper, C.D.; Williamson, A.D.; Miller, J.C.; Compton, R.N., Resonantly enhanced multiphoton ionization of pyrrole, N-methyl pyrrole, and furan, J. Chem. Phys., 1980, 73, 1527. [all data]

Williamson, Compton, et al., 1979
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]

Van Veen, 1976
Van Veen, E.H., Triplet π-π^* transitions in thiophene, furan and pyrrole by low-energy electron-impact spectroscopy, Chem. Phys. Lett., 1976, 41, 535. [all data]

Thorstad and Undheim, 1974
Thorstad, O.; Undheim, K., Mass spectrometry of onium compounds. XXIV. Ionisation potential in structure analysis of pyridodiazo-oxides, Chem. Scr., 1974, 6, 222. [all data]

Linda, Marino, et al., 1971
Linda, P.; Marino, G.; Pignataro, S., A comparison of sensitivities to substituent effects of five- membered heteroaromatic rings in gas phase ionization, J. Chem. Soc. B, 1971, 1585. [all data]

Derrick, Asbrink, et al., 1971
Derrick, P.J.; Asbrink, L.; Edqvist, O.; Jonsson, B.-O.; Lindholm, E., Rydberg series in small molecules. XII. Photoelectron spectroscopy and electronic structure of pyrrole, Intern. J. Mass Spectrom. Ion Phys., 1971, 6, 191. [all data]

Potapov and Yuzhakova, 1970
Potapov, V.K.; Yuzhakova, O.A., Photoionization and electronic structure of pyrrole and its methyl derivatives, Dokl. Akad. Nauk SSSR, 1970, 192, 131, In original 365. [all data]

Potapov and Bazhenov, 1970
Potapov, V.K.; Bazhenov, B.A., The photionization of pyrrole, furan, and thiophene, High Energy Chem., 1970, 505, In original 553. [all data]

Watanabe, Nakayama, et al., 1962
Watanabe, K.; Nakayama, T.; Mottl, J., Ionization potentials of some molecules, J. Quant. Spectry. Radiative Transfer, 1962, 2, 369. [all data]

Cradock, Findlay, et al., 1973
Cradock, S.; Findlay, R.H.; Palmer, M.H., The molecular energy levels of the azoles: A study by photoelectron spectroscopy and ab initio molecular orbital calculations, Tetrahedron, 1973, 29, 2173. [all data]

Sakurai and Jennings, 1981
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]

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]

Notes

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• Symbols used in this document:
  

  AE	Appearance energy
  IE (evaluated)	Recommended ionization energy
  ΔrG°	Free energy of reaction at standard conditions
  ΔrH°	Enthalpy of reaction at standard conditions

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