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
  • IR Spectrum
  • Mass spectrum (electron ionization)
  • References
  • Notes
• Other data available:
  • Gas phase ion energetics data
  • Ion clustering data
  • 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

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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)

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

References

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, IR Spectrum, 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]

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]

Notes

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, IR Spectrum, Mass spectrum (electron ionization), References

• Symbols used in this document:
  

  Cp,solid	Constant pressure heat capacity of solid
  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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