Barbituric acid

• Formula: C₄H₄N₂O₃
• Molecular weight: 128.0862
• IUPAC Standard InChI: InChI=1S/C4H4N2O3/c7-2-1-3(8)6-4(9)5-2/h1H2,(H2,5,6,7,8,9) Copy

  
• IUPAC Standard InChIKey: HNYOPLTXPVRDBG-UHFFFAOYSA-N Copy
• CAS Registry Number: 67-52-7
• Chemical structure:
  This structure is also available as a 2d Mol file
• Species with the same structure:
  • Barbituric acid
• Other names: 2,4,6(1H,3H,5H)-Pyrimidinetrione; Malonylurea; Pyrimidinetrione; Urea, N,N'-(1,3-dioxo-1,3-propanediyl)-; 2,4,6-Pyrimidinetriol; 2,4,6-Trihydroxypyrimidine; 2,4,6-Trioxohexahydropyrimidine; 6-Hydroxyuracil; 2,4,6-Pyrimidinetrione(1H,3H,5H)
• Information on this page:
  • Condensed phase thermochemistry data
  • Phase change data
  • Gas phase ion energetics data
  • Mass spectrum (electron ionization)
  • References
  • Notes
• Other data available:
  • Gas phase thermochemistry data
  • Reaction thermochemistry data
  • IR Spectrum
  • UV/Visible spectrum
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Condensed phase thermochemistry data

Go To: Top, Phase change data, 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 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 by: William E. Acree, Jr., James S. Chickos

Enthalpy of sublimation

Enthalpy of fusion

Gas phase ion energetics data

Go To: Top, Condensed phase thermochemistry data, Phase change 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 as indicated in comments:
B - John E. Bartmess
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi

Ionization energy determinations

De-protonation reactions

C₄H₃N₂O₃^- +  =

By formula: C₄H₃N₂O₃^- + H⁺ = C₄H₄N₂O₃

Mass spectrum (electron ionization)

Go To: Top, Condensed phase thermochemistry data, Phase change 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, Condensed phase thermochemistry data, Phase change 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.

Soldatova, Kabo, et al., 1990
Soldatova, T.V.; Kabo, G.Ya.; Kozyro, A.A.; Frenkel, M.L., Thermodynamic properties and tautomerism of barbituric acid, Russ. J. Phys. Chem. (Engl. Transl.), 1990, 64, 177-180. [all data]

Lemoult, 1904
Lemoult, M.P., Remarques sur une serie recenie de determinations calorimetriques, Compt. Rend., 1904, 663-635. [all data]

Soldatova, Kabo, et al., 1990, 2
Soldatova, T.V.; Kabo, G.Ya.; Kozyro, A.A.; Frenkel, M.L., Thermodynamic properties and tautomerism of barbituric acid, Zhur. Fiz. Khim., 1990, 64(2), 336-343. [all data]

Koshchenko, Ismailov, et al., 1985
Koshchenko, V.I.; Ismailov, T.S.; Potekhin, V.M.; Razikov, K.Kh., Thermodynamic functions of barbituric acid, Zhur. Prikl. Khim. (Leningrad), 1985, 58, 445-456. [all data]

Brunetti and Piacente, 1999
Brunetti, B.; Piacente, V., Sublimation Enthalpies Study for Barbituric, Tiobarbituric, and Selenobarbituric Acids from Their Vapor Pressure Measurements, J. Chem. Eng. Data, 1999, 44, 4, 809-812, https://doi.org/10.1021/je980300k . [all data]

Zielenkiewicz, Perlovich, et al., 1999
Zielenkiewicz, X.; Perlovich, G.L.; Wszelaka-Rylik, M., Journal of Thermal Analysis and Calorimetry, 1999, 57, 1, 225-234, https://doi.org/10.1023/A:1010179814511 . [all data]

Soldatova, Kabo, et al., 1990, 3
Soldatova, T.V.; Kabo, G.Ya.; Kozyro, A.A.; Frenkel, M.L., Thermodynamic properties and tautomerism of barbituric acid, Zh. Fiz. Khim., 1990, 64, 2, 336. [all data]

Roux, Temprado, et al., 2008
Roux, Maria Victoria; Temprado, Manuel; Notario, Rafael; Foces-Foces, Concepcion; Emel'yanenko, Vladimir N.; Verevkin, Sergey P., Structure-Energy Relationship in Barbituric Acid: A Calorimetric, Computational, and Crystallographic Study, J. Phys. Chem. A, 2008, 112, 32, 7455-7465, https://doi.org/10.1021/jp803370u . [all data]

Dougherty, Younathan, et al., 1978
Dougherty, D.; Younathan, E.S.; Voll, R.; Abdulnur, S.; McGlynn, S.P., Photoelectron spectroscopy of some biological molecules, J. Electron Spectrosc. Relat. Phenom., 1978, 13, 379. [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]

Notes

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

• Symbols used in this document:
  

  Cp,solid	Constant pressure heat capacity of solid
  S°solid,1 bar	Entropy of solid at standard conditions (1 bar)
  ΔcH°solid	Enthalpy of combustion of solid at standard conditions
  ΔfH°solid	Enthalpy of formation of solid at standard conditions
  ΔfusH	Enthalpy of fusion
  ΔrG°	Free energy of reaction at standard conditions
  ΔrH°	Enthalpy of reaction at standard conditions
  ΔsubH	Enthalpy of sublimation

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