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:
  • Gas phase thermochemistry data
  • Condensed phase thermochemistry data
  • Gas phase ion energetics data
  • References
  • Notes
• Other data available:
  • Phase change data
  • Reaction thermochemistry data
  • IR Spectrum
  • Mass spectrum (electron ionization)
  • UV/Visible spectrum
• Options:
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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

Gas phase ion energetics data

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry 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 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

References

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Gas phase ion energetics data, 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]

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, Gas phase thermochemistry data, Condensed phase thermochemistry data, Gas phase ion energetics data, 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°gas	Enthalpy of formation of gas at standard conditions
  ΔfH°solid	Enthalpy of formation of solid at standard conditions
  ΔrG°	Free energy of reaction at standard conditions
  ΔrH°	Enthalpy of reaction at standard conditions

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