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

Data at NIST subscription sites:

• NIST / TRC Web Thermo Tables, professional edition (thermophysical and thermochemical data)

NIST subscription sites provide data under the NIST Standard Reference Data Program, but require an annual fee to access. The purpose of the fee is to recover costs associated with the development of data collections included in such sites. Your institution may already be a subscriber. Follow the links above to find out more about the data in these sites and their terms of usage.

Condensed phase thermochemistry data

Go To: Top, IR Spectrum, Mass spectrum (electron ionization), UV/Visible spectrum, References, Notes

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

IR Spectrum

Go To: Top, Condensed phase thermochemistry data, Mass spectrum (electron ionization), UV/Visible spectrum, References, Notes

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)

Go To: Top, Condensed phase thermochemistry data, IR Spectrum, UV/Visible spectrum, 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

Notice: This spectrum may be better viewed with a Javascript and HTML 5 enabled browser.

For Zoom

1.) Enter the desired X axis range (e.g., 100, 200)

2.) Check here for automatic Y scaling

3.) Press here to zoom

Additional Data

UV/Visible spectrum

Go To: Top, Condensed phase thermochemistry data, IR Spectrum, 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: Victor Talrose, Alexander N. Yermakov, Alexy A. Usov, Antonina A. Goncharova, Axlexander N. Leskin, Natalia A. Messineva, Natalia V. Trusova, Margarita V. Efimkina

Spectrum

Notice: This spectrum may be better viewed with a Javascript and HTML 5 enabled browser.

For Zoom

1.) Enter the desired X axis range (e.g., 100, 200)

2.) Check here for automatic Y scaling

3.) Press here to zoom

Additional Data

References

Go To: Top, Condensed phase thermochemistry 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.

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]

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]

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]

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

Notes

Go To: Top, Condensed phase thermochemistry data, IR Spectrum, Mass spectrum (electron ionization), UV/Visible spectrum, 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°solid	Enthalpy of formation of solid at standard conditions

• Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
• The National Institute of Standards and Technology (NIST) uses its best efforts to deliver a high quality copy of the Database and to verify that the data contained therein have been selected on the basis of sound scientific judgment. However, NIST makes no warranties to that effect, and NIST shall not be liable for any damage that may result from errors or omissions in the Database.
• Customer support for NIST Standard Reference Data products.