Uracil

• Formula: C₄H₄N₂O₂
• Molecular weight: 112.0868
• IUPAC Standard InChI: InChI=1S/C4H4N2O2/c7-3-1-2-5-4(8)6-3/h1-2H,(H2,5,6,7,8) Copy

  
• IUPAC Standard InChIKey: ISAKRJDGNUQOIC-UHFFFAOYSA-N Copy
• CAS Registry Number: 66-22-8
• Chemical structure:
  This structure is also available as a 2d Mol file
• Other names: 2,4(1H,3H)-Pyrimidinedione; Pirod; Pyrod; RU 12709; Ura; 2,4-Dihydroxypyrimidine; 2,4-Dioxopyrimidine; 2,4-Pyrimidinediol; 2,4-Pyrimidinedione; 2,6-Dihydroxypyrimidine; Hybar X; 1H-Pyrimidine-2,4-dione; 2-Hydroxy-4(1H)-pyrimidinone; 2-Hydroxy-4(3H)-pyrimidinone; 2,4-Dioxypyrimidine; 4-Hydroxy-2(1H)-pyrimidinone; NSC 3970
• Permanent link for this species. Use this link for bookmarking this species for future reference.
• Information on this page:
  • Gas phase thermochemistry data
  • Gas phase ion energetics data
  • Mass spectrum (electron ionization)
  • References
  • Notes
• Other data available:
  • Condensed phase thermochemistry data
  • Phase change data
  • Reaction thermochemistry data
  • Ion clustering data
  • IR Spectrum
  • UV/Visible spectrum
• Data at other public NIST sites:
  • X-ray Photoelectron Spectroscopy Database, version 5.0
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Gas phase thermochemistry data

Go To: Top, Gas phase ion energetics data, Mass spectrum (electron ionization), References, Notes

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

Gas phase ion energetics data

Go To: Top, Gas phase thermochemistry data, Mass spectrum (electron ionization), 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

Data compiled as indicated in comments:
MM - Michael M. Meot-Ner (Mautner)
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
B - John E. Bartmess

Electron affinity determinations

Proton affinity at 298K

Ionization energy determinations

Mass spectrum (electron ionization)

Go To: Top, Gas 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 by: NIST Mass Spectrometry Data Center, William E. Wallace, director

Spectrum

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Additional Data

References

Go To: Top, Gas phase thermochemistry data, Gas phase ion energetics data, Mass spectrum (electron ionization), Notes

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

Nabavian, Sabbah, et al., 1977
Nabavian, P.M.; Sabbah, R.; Chastel, R.; Laffitte, M., Thermodynamique de composes azotes. II. Etude thermochimique des acides aminobenzoiques, de la pyrimidine, de l'uracile et de la thymine., J. Chim. Phys., 1977, 74, 115-126. [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]

Desfrancois, Abdoul-Carime, et al., 1999
Desfrancois, C.; Abdoul-Carime, H.; Carles, S.; Periquet, V.; Schermann, J.P.; Smith, D.M.A.; Adamowicz, L., Experimental and theoretical ab initio study of the influence of N-methylation on the dipole-bound electron affinities of thymine and uracil, J. Chem. Phys., 1999, 110, 24, 11876-11883, https://doi.org/10.1063/1.479175 . [all data]

Schiedt, Weinkauf, et al., 1998
Schiedt, J.; Weinkauf, R.; Neumark, D.M.; Schlag, E.W., Anion spectroscopy of uracil, thymine and the amino-oxo and amino-hydroxy tautomers of cytosine and their water clusters, Chem. Phys., 1998, 239, 1-3, 511-524, https://doi.org/10.1016/S0301-0104(98)00361-9 . [all data]

Desfrancois, Abdoul-Carime, et al., 1996
Desfrancois, C.; Abdoul-Carime, H.; Schermann, J.P., Electron Attachment to Isolated Nucleic Acid Bases, J. Chem. Phys., 1996, 104, 19, 7792, https://doi.org/10.1063/1.471484 . [all data]

Hendricks, Lyapustina, et al., 1996
Hendricks, J.H.; Lyapustina, S.A.; de Clercq, H.L.; Snodgrass, J.T.; Bowen, K.H., Dipole bound, nucleic Acid Base Anions Studied via Negative Ion Photoelectron Spectroscopy, J. Chem. Phys., 1996, 104, 19, 7788, https://doi.org/10.1063/1.471482 . [all data]

Aflatooni, Gallup, et al., 1998
Aflatooni, K.; Gallup, G.A.; Burrows, P.D., Electron Attachment Energies of the DNA Bases, J. Phys. Chem., 1998, 102, 31, 6205, https://doi.org/10.1021/jp980865n . [all data]

Li, Bowen, et al., 2007
Li, X.; Bowen, K.H.; Haranczyk, M.; Bachorz, R.A.; Mazurkiewicz, K.; Rak, J.; Gutowski, M., Photoelectron spectroscopy of adiabatically bound valence anions of rare tautomers of the nucleic acid bases, J. Chem. Phys., 2007, 127, 17, 174309, https://doi.org/10.1063/1.2795719 . [all data]

Wolken and Turecek, 2000
Wolken, J.K.; Turecek, F., Proton affinity of uracil. A computational study of protonation sites, J. Am. Soc. Mass Spectrom., 2000, 11, 1065. [all data]

Yu, O'Donnell, et al., 1981
Yu, C.; O'Donnell, T.J.; LeBreton, P.R., Ultraviolet photoelectron studies of volatile nucleoside models. Vertical ionization potential measurements of methylated uridine, thymidine, cytidine, and adenosine, J. Phys. Chem., 1981, 85, 3851. [all data]

Verkin, Sukodub, et al., 1976
Verkin, B.I.; Sukodub, L.F.; Yanson, I.K., Ionization potentials of nitrogenous bases of of nucleic acids, Dokl. Akad. Nauk SSSR, 1976, 228, 1452. [all data]

Zaretskii, Sadovskaya, et al., 1971
Zaretskii, V.I.; Sadovskaya, V.L.; Wulfson, N.S.; Sizoy, V.F.; Merimson, V.G., Mass spectrometry of steroid systems-XXI. Appearance and ionization potentials for the stereoisomers of the D-homoestrane series, Org. Mass Spectrom., 1971, 5, 1179. [all data]

Lifschitz, Bergmann, et al., 1967
Lifschitz, C.; Bergmann, E.D.; Pullman, B., The ionization potentials of biological purines and pyrimidines, Tetrahedron Lett., 1967, 4583. [all data]

Palmer, Simpson, et al., 1980
Palmer, M.H.; Simpson, I.; Platenkamp, R.J., The electronic structure of flavin derivatives, J. Mol. Struct., 1980, 66, 243. [all data]

Dougherty, Wittel, et al., 1976
Dougherty, D.; Wittel, K.; Meeks, J.; McGlynn, S.P., Photoelectron spectroscopy of carbonyls. Ureas, uracils, and thymine, J. Am. Chem. Soc., 1976, 98, 3815. [all data]

Lauer, Schafer, et al., 1975
Lauer, G.; Schafer, W.; Schweig, A., Functional subunits in the nucleic acid bases uracil and thymine, Tetrahedron Lett., 1975, 45, 3939. [all data]

Hush and Cheung, 1975
Hush, N.S.; Cheung, A.S., Ionization potentials and donor properties of nucleic acid bases and related compounds, Chem. Phys. Lett., 1975, 34, 11. [all data]

Padva, LeBreton, et al., 1974
Padva, A.; LeBreton, P.R.; Dinerstein, R.J.; Ridyard, J.N.A., UV photoelectron studies of biological pyrimidines: The electronic structure of uracil, Biochem. Biophys. Res. Commun., 1974, 60, 1262. [all data]

Notes

Go To: Top, Gas phase thermochemistry data, Gas phase ion energetics data, Mass spectrum (electron ionization), References

• Symbols used in this document:
  

  EA	Electron affinity
  ΔfH°gas	Enthalpy of formation of gas at standard conditions

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