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
  • Condensed phase thermochemistry data
  • Phase change data
  • Reaction thermochemistry data
  • Gas phase ion energetics data
  • Ion clustering data
  • IR Spectrum
  • Mass spectrum (electron ionization)
  • UV/Visible spectrum
  • References
  • Notes
• Data at other public NIST sites:
  • X-ray Photoelectron Spectroscopy Database, version 5.0
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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 by: 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 solid

Phase change 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:
AC - William E. Acree, Jr., James S. Chickos
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein

Enthalpy of sublimation

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 by: 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: Na⁺ + C₄H₄N₂O₂ = (Na⁺ • C₄H₄N₂O₂)

 +  = ( • )

By formula: K⁺ + C₄H₄N₂O₂ = (K⁺ • C₄H₄N₂O₂)

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

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

Ion clustering 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 by: Robert C. Dunbar

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

 +  = ( • )

By formula: K⁺ + C₄H₄N₂O₂ = (K⁺ • C₄H₄N₂O₂)

 +  = ( • )

By formula: Na⁺ + C₄H₄N₂O₂ = (Na⁺ • C₄H₄N₂O₂)

IR Spectrum

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Data compiled by: Coblentz Society, Inc.

• SOLID (0.7 mg / 650 mg KBr DISC); PERKIN-ELMER 21 (GRATING); (ADJUSTED addcm-115-12-3); 2 cm^-1 resolution
• SOLID (1.2 mg / 400 mg KBr DISC) $$ PURITY - ANALYTICAL; PERKIN-ELMER 180 (GRATING); DIGITIZED BY COBLENTZ SOCIETY (BATCH II) FROM HARD COPY; 2 cm^-1 resolution
• SOLID (SPLIT MULL); DOW KBr FOREPRISM-GRATING; DIGITIZED BY COBLENTZ SOCIETY (BATCH I) FROM HARD COPY; 2 cm^-1 resolution

Mass spectrum (electron ionization)

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

Spectrum

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Additional Data

UV/Visible spectrum

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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 by: Victor Talrose, Alexander N. Yermakov, Alexy A. Usov, Antonina A. Goncharova, Axlexander N. Leskin, Natalia A. Messineva, Natalia V. Trusova, Margarita V. Efimkina

Spectrum

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Additional Data

References

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering data, IR Spectrum, Mass spectrum (electron ionization), UV/Visible spectrum, 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]

Wilson, Watson, et al., 1979
Wilson, S.R.; Watson, I.D.; Malcolm, G.N., Enthalpies of formation of solid cytosine, L-histidine, and uracil, J. Chem. Thermodyn., 1979, 11, 911-912. [all data]

Kilday, 1978
Kilday, M.V., Enthalpies of solution of the nucleic acid bases. 4. Uracil in water, J. Res., 1978, NBS 83, 547-554. [all data]

Bardi, Bencivenni, et al., 1980
Bardi, G.; Bencivenni, L.; Ferro, D.; Martini, B.; Nunziante Cesaro, S.; Teghil, R., Thermodynamic study of the vaporization of uracil, Thermochimica Acta, 1980, 40, 2, 275-282, https://doi.org/10.1016/0040-6031(80)87229-7 . [all data]

Clark, Peschel, et al., 1965
Clark, L.B.; Peschel, G.G.; Tinoco, I., Jr., Vapor spectra and heats of vaporization of some purine and pyrmidine bases, J. Phys. Chem., 1965, 69, 3615. [all data]

de Barros, Medina, et al., 2006
de Barros, A.L.F.; Medina, A.; Zappa, F.; Pereira, J.M.; Bessa, E.; Martins, M.H.P.; Coelho, L.F.S.; Wolff, W.; de Castro Faria, N.V., A simple experimental arrangement for measuring the vapour pressures and sublimation enthalpies by the Knudsen effusion method: Application to DNA and RNA bases, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2006, 560, 2, 219-223, https://doi.org/10.1016/j.nima.2006.01.026 . [all data]

Szterner, Kaminski, et al., 2002
Szterner, Piotr; Kaminski, Miron; Zielenkiewicz, Anna, Vapour pressures, molar enthalpies of sublimation and molar enthalpies of solution in water of five halogenated derivatives of uracil, The Journal of Chemical Thermodynamics, 2002, 34, 7, 1005-1012, https://doi.org/10.1006/jcht.2000.0987 . [all data]

Brunetti, Piacente, et al., 2000
Brunetti, Bruno; Piacente, Vincenzo; Portalone, Gustavo, Sublimation Enthalpies of Some Methyl Derivatives of Uracil from Vapor Pressure Measurements, J. Chem. Eng. Data, 2000, 45, 2, 242-246, https://doi.org/10.1021/je9902802 . [all data]

Teplitsky, Yanson, et al., 1980
Teplitsky, A.B.; Yanson, I.K.; Glukhova, O.T.; Zielenkiwicz, A.; Zielenkiewicz, W.; Wierzchowski, K.L., Thermochemistry of aqueous solutions of alkylated nucleic acid bases, Biophysical Chemistry, 1980, 11, 1, 17-21, https://doi.org/10.1016/0301-4622(80)85003-4 . [all data]

Yanson, Teplitsky, et al., 1979
Yanson, I.K.; Teplitsky, A.B.; Sukhodub, L.F., Experimental studies of molecular interactions between nitrogen bases of nucleic acids, Biopolymers, 1979, 18, 5, 1149-1170, https://doi.org/10.1002/bip.1979.360180510 . [all data]

Nowak, Szczepaniak, et al., 1978
Nowak, M.J.; Szczepaniak, K.; Barski, A.; Shugar, D.Z., Z. Naturforsch. C, 1978, 33C, 876. [all data]

Nabavian, Sabbah, et al., 1977, 2
Nabavian, M.; Sabbah, R.; Chastel, R.; Laffitte, M., J. Chim. Phys.Phys.-Chim. Biol., 1977, 74, 115. [all data]

Yanson and Teplitskii, 1975
Yanson, I.K.; Teplitskii, A.B., Zh. Fiz. Khim., 1975, 49, 736. [all data]

Yanson, Verkin, et al., 1974
Yanson, I.K.; Verkin, B.I.; Shklyarevskii, O.I.; Teplitskii, A.B., Stud. Biophys., 1974, 46, 1, 29. [all data]

Rodgers and Armentrout, 2000
Rodgers, M.T.; Armentrout, P.B., Noncovalent Interactions of Nucleic Acid Bases (Uracil, Thymine, and Adenine) with Alkali Metal Ions. Threshold Collision-Induced Dissociation and Theoretical Studies, J. Am. Chem. Soc., 2000, 121, 35, 8548, https://doi.org/10.1021/ja001638d . [all data]

Cerda and Wesdemiotis, 1996
Cerda, B.A.; Wesdemiotis, C., PAs of Peptides, J. Am. Chem. Soc., 1996, 118, 11884. [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]

Stimson, 1949
Stimson, M.M., J. Am. Chem. Soc., 1949, 71, 1470. [all data]

Notes

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering data, IR Spectrum, Mass spectrum (electron ionization), UV/Visible spectrum, References

• Symbols used in this document:
  

  Cp,solid	Constant pressure heat capacity of solid
  EA	Electron affinity
  ΔcH°solid	Enthalpy of combustion of solid at standard conditions
  ΔfH°gas	Enthalpy of formation of gas at standard conditions
  ΔfH°solid	Enthalpy of formation of solid at standard conditions
  ΔrH°	Enthalpy of reaction at standard conditions
  ΔsubH	Enthalpy of sublimation
  ΔsubH°	Enthalpy of sublimation at standard conditions

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